granicus.if.org Git - postgresql/blob - src/backend/optimizer/plan/createplan.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * createplan.c
   4  *        Routines to create the desired plan for processing a query.
   5  *        Planning is complete, we just need to convert the selected
   6  *        Path into a Plan.
   7  *
   8  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
   9  * Portions Copyright (c) 1994, Regents of the University of California
  10  *
  11  *
  12  * IDENTIFICATION
  13  *        src/backend/optimizer/plan/createplan.c
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <limits.h>
  20 #include <math.h>
  21
  22 #include "access/skey.h"
  23 #include "foreign/fdwapi.h"
  24 #include "miscadmin.h"
  25 #include "nodes/makefuncs.h"
  26 #include "nodes/nodeFuncs.h"
  27 #include "optimizer/clauses.h"
  28 #include "optimizer/cost.h"
  29 #include "optimizer/paths.h"
  30 #include "optimizer/plancat.h"
  31 #include "optimizer/planmain.h"
  32 #include "optimizer/predtest.h"
  33 #include "optimizer/restrictinfo.h"
  34 #include "optimizer/subselect.h"
  35 #include "optimizer/tlist.h"
  36 #include "optimizer/var.h"
  37 #include "parser/parse_clause.h"
  38 #include "parser/parsetree.h"
  39 #include "utils/lsyscache.h"
  40
  41
  42 static Plan *create_plan_recurse(PlannerInfo *root, Path *best_path);
  43 static Plan *create_scan_plan(PlannerInfo *root, Path *best_path);
  44 static List *build_relation_tlist(RelOptInfo *rel);
  45 static bool use_physical_tlist(PlannerInfo *root, RelOptInfo *rel);
  46 static void disuse_physical_tlist(Plan *plan, Path *path);
  47 static Plan *create_gating_plan(PlannerInfo *root, Plan *plan, List *quals);
  48 static Plan *create_join_plan(PlannerInfo *root, JoinPath *best_path);
  49 static Plan *create_append_plan(PlannerInfo *root, AppendPath *best_path);
  50 static Plan *create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path);
  51 static Result *create_result_plan(PlannerInfo *root, ResultPath *best_path);
  52 static Material *create_material_plan(PlannerInfo *root, MaterialPath *best_path);
  53 static Plan *create_unique_plan(PlannerInfo *root, UniquePath *best_path);
  54 static SeqScan *create_seqscan_plan(PlannerInfo *root, Path *best_path,
  55                                         List *tlist, List *scan_clauses);
  56 static IndexScan *create_indexscan_plan(PlannerInfo *root, IndexPath *best_path,
  57                                           List *tlist, List *scan_clauses);
  58 static BitmapHeapScan *create_bitmap_scan_plan(PlannerInfo *root,
  59                                                 BitmapHeapPath *best_path,
  60                                                 List *tlist, List *scan_clauses);
  61 static Plan *create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
  62                                           List **qual, List **indexqual);
  63 static TidScan *create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
  64                                         List *tlist, List *scan_clauses);
  65 static SubqueryScan *create_subqueryscan_plan(PlannerInfo *root, Path *best_path,
  66                                                  List *tlist, List *scan_clauses);
  67 static FunctionScan *create_functionscan_plan(PlannerInfo *root, Path *best_path,
  68                                                  List *tlist, List *scan_clauses);
  69 static ValuesScan *create_valuesscan_plan(PlannerInfo *root, Path *best_path,
  70                                            List *tlist, List *scan_clauses);
  71 static CteScan *create_ctescan_plan(PlannerInfo *root, Path *best_path,
  72                                         List *tlist, List *scan_clauses);
  73 static WorkTableScan *create_worktablescan_plan(PlannerInfo *root, Path *best_path,
  74                                                   List *tlist, List *scan_clauses);
  75 static ForeignScan *create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
  76                                                 List *tlist, List *scan_clauses);
  77 static NestLoop *create_nestloop_plan(PlannerInfo *root, NestPath *best_path,
  78                                          Plan *outer_plan, Plan *inner_plan);
  79 static MergeJoin *create_mergejoin_plan(PlannerInfo *root, MergePath *best_path,
  80                                           Plan *outer_plan, Plan *inner_plan);
  81 static HashJoin *create_hashjoin_plan(PlannerInfo *root, HashPath *best_path,
  82                                          Plan *outer_plan, Plan *inner_plan);
  83 static Node *replace_nestloop_params(PlannerInfo *root, Node *expr);
  84 static Node *replace_nestloop_params_mutator(Node *node, PlannerInfo *root);
  85 static List *fix_indexqual_references(PlannerInfo *root, IndexPath *index_path,
  86                                                  List *indexquals);
  87 static List *fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path,
  88                                                         List *indexorderbys);
  89 static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index);
  90 static List *get_switched_clauses(List *clauses, Relids outerrelids);
  91 static List *order_qual_clauses(PlannerInfo *root, List *clauses);
  92 static void copy_path_costsize(Plan *dest, Path *src);
  93 static void copy_plan_costsize(Plan *dest, Plan *src);
  94 static SeqScan *make_seqscan(List *qptlist, List *qpqual, Index scanrelid);
  95 static IndexScan *make_indexscan(List *qptlist, List *qpqual, Index scanrelid,
  96                            Oid indexid, List *indexqual, List *indexqualorig,
  97                            List *indexorderby, List *indexorderbyorig,
  98                            ScanDirection indexscandir);
  99 static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
 100                                           List *indexqual,
 101                                           List *indexqualorig);
 102 static BitmapHeapScan *make_bitmap_heapscan(List *qptlist,
 103                                          List *qpqual,
 104                                          Plan *lefttree,
 105                                          List *bitmapqualorig,
 106                                          Index scanrelid);
 107 static TidScan *make_tidscan(List *qptlist, List *qpqual, Index scanrelid,
 108                          List *tidquals);
 109 static FunctionScan *make_functionscan(List *qptlist, List *qpqual,
 110                                   Index scanrelid, Node *funcexpr, List *funccolnames,
 111                                   List *funccoltypes, List *funccoltypmods,
 112                                   List *funccolcollations);
 113 static ValuesScan *make_valuesscan(List *qptlist, List *qpqual,
 114                                 Index scanrelid, List *values_lists);
 115 static CteScan *make_ctescan(List *qptlist, List *qpqual,
 116                          Index scanrelid, int ctePlanId, int cteParam);
 117 static WorkTableScan *make_worktablescan(List *qptlist, List *qpqual,
 118                                    Index scanrelid, int wtParam);
 119 static ForeignScan *make_foreignscan(List *qptlist, List *qpqual,
 120                                  Index scanrelid, bool fsSystemCol, FdwPlan *fdwplan);
 121 static BitmapAnd *make_bitmap_and(List *bitmapplans);
 122 static BitmapOr *make_bitmap_or(List *bitmapplans);
 123 static NestLoop *make_nestloop(List *tlist,
 124                           List *joinclauses, List *otherclauses, List *nestParams,
 125                           Plan *lefttree, Plan *righttree,
 126                           JoinType jointype);
 127 static HashJoin *make_hashjoin(List *tlist,
 128                           List *joinclauses, List *otherclauses,
 129                           List *hashclauses,
 130                           Plan *lefttree, Plan *righttree,
 131                           JoinType jointype);
 132 static Hash *make_hash(Plan *lefttree,
 133                   Oid skewTable,
 134                   AttrNumber skewColumn,
 135                   bool skewInherit,
 136                   Oid skewColType,
 137                   int32 skewColTypmod);
 138 static MergeJoin *make_mergejoin(List *tlist,
 139                            List *joinclauses, List *otherclauses,
 140                            List *mergeclauses,
 141                            Oid *mergefamilies,
 142                            Oid *mergecollations,
 143                            int *mergestrategies,
 144                            bool *mergenullsfirst,
 145                            Plan *lefttree, Plan *righttree,
 146                            JoinType jointype);
 147 static Sort *make_sort(PlannerInfo *root, Plan *lefttree, int numCols,
 148                   AttrNumber *sortColIdx, Oid *sortOperators,
 149                   Oid *collations, bool *nullsFirst,
 150                   double limit_tuples);
 151 static Plan *prepare_sort_from_pathkeys(PlannerInfo *root,
 152                                                    Plan *lefttree, List *pathkeys,
 153                                                    bool adjust_tlist_in_place,
 154                                                    int *p_numsortkeys,
 155                                                    AttrNumber **p_sortColIdx,
 156                                                    Oid **p_sortOperators,
 157                                                    Oid **p_collations,
 158                                                    bool **p_nullsFirst);
 159 static Material *make_material(Plan *lefttree);
 160
 161
 162 /*
 163  * create_plan
 164  *        Creates the access plan for a query by recursively processing the
 165  *        desired tree of pathnodes, starting at the node 'best_path'.  For
 166  *        every pathnode found, we create a corresponding plan node containing
 167  *        appropriate id, target list, and qualification information.
 168  *
 169  *        The tlists and quals in the plan tree are still in planner format,
 170  *        ie, Vars still correspond to the parser's numbering.  This will be
 171  *        fixed later by setrefs.c.
 172  *
 173  *        best_path is the best access path
 174  *
 175  *        Returns a Plan tree.
 176  */
 177 Plan *
 178 create_plan(PlannerInfo *root, Path *best_path)
 179 {
 180         Plan       *plan;
 181
 182         /* Initialize this module's private workspace in PlannerInfo */
 183         root->curOuterRels = NULL;
 184         root->curOuterParams = NIL;
 185
 186         /* Recursively process the path tree */
 187         plan = create_plan_recurse(root, best_path);
 188
 189         /* Check we successfully assigned all NestLoopParams to plan nodes */
 190         if (root->curOuterParams != NIL)
 191                 elog(ERROR, "failed to assign all NestLoopParams to plan nodes");
 192
 193         return plan;
 194 }
 195
 196 /*
 197  * create_plan_recurse
 198  *        Recursive guts of create_plan().
 199  */
 200 static Plan *
 201 create_plan_recurse(PlannerInfo *root, Path *best_path)
 202 {
 203         Plan       *plan;
 204
 205         switch (best_path->pathtype)
 206         {
 207                 case T_SeqScan:
 208                 case T_IndexScan:
 209                 case T_BitmapHeapScan:
 210                 case T_TidScan:
 211                 case T_SubqueryScan:
 212                 case T_FunctionScan:
 213                 case T_ValuesScan:
 214                 case T_CteScan:
 215                 case T_WorkTableScan:
 216                 case T_ForeignScan:
 217                         plan = create_scan_plan(root, best_path);
 218                         break;
 219                 case T_HashJoin:
 220                 case T_MergeJoin:
 221                 case T_NestLoop:
 222                         plan = create_join_plan(root,
 223                                                                         (JoinPath *) best_path);
 224                         break;
 225                 case T_Append:
 226                         plan = create_append_plan(root,
 227                                                                           (AppendPath *) best_path);
 228                         break;
 229                 case T_MergeAppend:
 230                         plan = create_merge_append_plan(root,
 231                                                                                         (MergeAppendPath *) best_path);
 232                         break;
 233                 case T_Result:
 234                         plan = (Plan *) create_result_plan(root,
 235                                                                                            (ResultPath *) best_path);
 236                         break;
 237                 case T_Material:
 238                         plan = (Plan *) create_material_plan(root,
 239                                                                                                  (MaterialPath *) best_path);
 240                         break;
 241                 case T_Unique:
 242                         plan = create_unique_plan(root,
 243                                                                           (UniquePath *) best_path);
 244                         break;
 245                 default:
 246                         elog(ERROR, "unrecognized node type: %d",
 247                                  (int) best_path->pathtype);
 248                         plan = NULL;            /* keep compiler quiet */
 249                         break;
 250         }
 251
 252         return plan;
 253 }
 254
 255 /*
 256  * create_scan_plan
 257  *       Create a scan plan for the parent relation of 'best_path'.
 258  */
 259 static Plan *
 260 create_scan_plan(PlannerInfo *root, Path *best_path)
 261 {
 262         RelOptInfo *rel = best_path->parent;
 263         List       *tlist;
 264         List       *scan_clauses;
 265         Plan       *plan;
 266
 267         /*
 268          * For table scans, rather than using the relation targetlist (which is
 269          * only those Vars actually needed by the query), we prefer to generate a
 270          * tlist containing all Vars in order.  This will allow the executor to
 271          * optimize away projection of the table tuples, if possible.  (Note that
 272          * planner.c may replace the tlist we generate here, forcing projection to
 273          * occur.)
 274          */
 275         if (use_physical_tlist(root, rel))
 276         {
 277                 tlist = build_physical_tlist(root, rel);
 278                 /* if fail because of dropped cols, use regular method */
 279                 if (tlist == NIL)
 280                         tlist = build_relation_tlist(rel);
 281         }
 282         else
 283                 tlist = build_relation_tlist(rel);
 284
 285         /*
 286          * Extract the relevant restriction clauses from the parent relation. The
 287          * executor must apply all these restrictions during the scan, except for
 288          * pseudoconstants which we'll take care of below.
 289          */
 290         scan_clauses = rel->baserestrictinfo;
 291
 292         switch (best_path->pathtype)
 293         {
 294                 case T_SeqScan:
 295                         plan = (Plan *) create_seqscan_plan(root,
 296                                                                                                 best_path,
 297                                                                                                 tlist,
 298                                                                                                 scan_clauses);
 299                         break;
 300
 301                 case T_IndexScan:
 302                         plan = (Plan *) create_indexscan_plan(root,
 303                                                                                                   (IndexPath *) best_path,
 304                                                                                                   tlist,
 305                                                                                                   scan_clauses);
 306                         break;
 307
 308                 case T_BitmapHeapScan:
 309                         plan = (Plan *) create_bitmap_scan_plan(root,
 310                                                                                                 (BitmapHeapPath *) best_path,
 311                                                                                                         tlist,
 312                                                                                                         scan_clauses);
 313                         break;
 314
 315                 case T_TidScan:
 316                         plan = (Plan *) create_tidscan_plan(root,
 317                                                                                                 (TidPath *) best_path,
 318                                                                                                 tlist,
 319                                                                                                 scan_clauses);
 320                         break;
 321
 322                 case T_SubqueryScan:
 323                         plan = (Plan *) create_subqueryscan_plan(root,
 324                                                                                                          best_path,
 325                                                                                                          tlist,
 326                                                                                                          scan_clauses);
 327                         break;
 328
 329                 case T_FunctionScan:
 330                         plan = (Plan *) create_functionscan_plan(root,
 331                                                                                                          best_path,
 332                                                                                                          tlist,
 333                                                                                                          scan_clauses);
 334                         break;
 335
 336                 case T_ValuesScan:
 337                         plan = (Plan *) create_valuesscan_plan(root,
 338                                                                                                    best_path,
 339                                                                                                    tlist,
 340                                                                                                    scan_clauses);
 341                         break;
 342
 343                 case T_CteScan:
 344                         plan = (Plan *) create_ctescan_plan(root,
 345                                                                                                 best_path,
 346                                                                                                 tlist,
 347                                                                                                 scan_clauses);
 348                         break;
 349
 350                 case T_WorkTableScan:
 351                         plan = (Plan *) create_worktablescan_plan(root,
 352                                                                                                           best_path,
 353                                                                                                           tlist,
 354                                                                                                           scan_clauses);
 355                         break;
 356
 357                 case T_ForeignScan:
 358                         plan = (Plan *) create_foreignscan_plan(root,
 359                                                                                                         (ForeignPath *) best_path,
 360                                                                                                         tlist,
 361                                                                                                         scan_clauses);
 362                         break;
 363
 364                 default:
 365                         elog(ERROR, "unrecognized node type: %d",
 366                                  (int) best_path->pathtype);
 367                         plan = NULL;            /* keep compiler quiet */
 368                         break;
 369         }
 370
 371         /*
 372          * If there are any pseudoconstant clauses attached to this node, insert a
 373          * gating Result node that evaluates the pseudoconstants as one-time
 374          * quals.
 375          */
 376         if (root->hasPseudoConstantQuals)
 377                 plan = create_gating_plan(root, plan, scan_clauses);
 378
 379         return plan;
 380 }
 381
 382 /*
 383  * Build a target list (ie, a list of TargetEntry) for a relation.
 384  */
 385 static List *
 386 build_relation_tlist(RelOptInfo *rel)
 387 {
 388         List       *tlist = NIL;
 389         int                     resno = 1;
 390         ListCell   *v;
 391
 392         foreach(v, rel->reltargetlist)
 393         {
 394                 /* Do we really need to copy here?      Not sure */
 395                 Node       *node = (Node *) copyObject(lfirst(v));
 396
 397                 tlist = lappend(tlist, makeTargetEntry((Expr *) node,
 398                                                                                            resno,
 399                                                                                            NULL,
 400                                                                                            false));
 401                 resno++;
 402         }
 403         return tlist;
 404 }
 405
 406 /*
 407  * use_physical_tlist
 408  *              Decide whether to use a tlist matching relation structure,
 409  *              rather than only those Vars actually referenced.
 410  */
 411 static bool
 412 use_physical_tlist(PlannerInfo *root, RelOptInfo *rel)
 413 {
 414         int                     i;
 415         ListCell   *lc;
 416
 417         /*
 418          * We can do this for real relation scans, subquery scans, function scans,
 419          * values scans, and CTE scans (but not for, eg, joins).
 420          */
 421         if (rel->rtekind != RTE_RELATION &&
 422                 rel->rtekind != RTE_SUBQUERY &&
 423                 rel->rtekind != RTE_FUNCTION &&
 424                 rel->rtekind != RTE_VALUES &&
 425                 rel->rtekind != RTE_CTE)
 426                 return false;
 427
 428         /*
 429          * Can't do it with inheritance cases either (mainly because Append
 430          * doesn't project).
 431          */
 432         if (rel->reloptkind != RELOPT_BASEREL)
 433                 return false;
 434
 435         /*
 436          * Can't do it if any system columns or whole-row Vars are requested.
 437          * (This could possibly be fixed but would take some fragile assumptions
 438          * in setrefs.c, I think.)
 439          */
 440         for (i = rel->min_attr; i <= 0; i++)
 441         {
 442                 if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
 443                         return false;
 444         }
 445
 446         /*
 447          * Can't do it if the rel is required to emit any placeholder expressions,
 448          * either.
 449          */
 450         foreach(lc, root->placeholder_list)
 451         {
 452                 PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
 453
 454                 if (bms_nonempty_difference(phinfo->ph_needed, rel->relids) &&
 455                         bms_is_subset(phinfo->ph_eval_at, rel->relids))
 456                         return false;
 457         }
 458
 459         return true;
 460 }
 461
 462 /*
 463  * disuse_physical_tlist
 464  *              Switch a plan node back to emitting only Vars actually referenced.
 465  *
 466  * If the plan node immediately above a scan would prefer to get only
 467  * needed Vars and not a physical tlist, it must call this routine to
 468  * undo the decision made by use_physical_tlist().      Currently, Hash, Sort,
 469  * and Material nodes want this, so they don't have to store useless columns.
 470  */
 471 static void
 472 disuse_physical_tlist(Plan *plan, Path *path)
 473 {
 474         /* Only need to undo it for path types handled by create_scan_plan() */
 475         switch (path->pathtype)
 476         {
 477                 case T_SeqScan:
 478                 case T_IndexScan:
 479                 case T_BitmapHeapScan:
 480                 case T_TidScan:
 481                 case T_SubqueryScan:
 482                 case T_FunctionScan:
 483                 case T_ValuesScan:
 484                 case T_CteScan:
 485                 case T_WorkTableScan:
 486                 case T_ForeignScan:
 487                         plan->targetlist = build_relation_tlist(path->parent);
 488                         break;
 489                 default:
 490                         break;
 491         }
 492 }
 493
 494 /*
 495  * create_gating_plan
 496  *        Deal with pseudoconstant qual clauses
 497  *
 498  * If the node's quals list includes any pseudoconstant quals, put them
 499  * into a gating Result node atop the already-built plan.  Otherwise,
 500  * return the plan as-is.
 501  *
 502  * Note that we don't change cost or size estimates when doing gating.
 503  * The costs of qual eval were already folded into the plan's startup cost.
 504  * Leaving the size alone amounts to assuming that the gating qual will
 505  * succeed, which is the conservative estimate for planning upper queries.
 506  * We certainly don't want to assume the output size is zero (unless the
 507  * gating qual is actually constant FALSE, and that case is dealt with in
 508  * clausesel.c).  Interpolating between the two cases is silly, because
 509  * it doesn't reflect what will really happen at runtime, and besides which
 510  * in most cases we have only a very bad idea of the probability of the gating
 511  * qual being true.
 512  */
 513 static Plan *
 514 create_gating_plan(PlannerInfo *root, Plan *plan, List *quals)
 515 {
 516         List       *pseudoconstants;
 517
 518         /* Sort into desirable execution order while still in RestrictInfo form */
 519         quals = order_qual_clauses(root, quals);
 520
 521         /* Pull out any pseudoconstant quals from the RestrictInfo list */
 522         pseudoconstants = extract_actual_clauses(quals, true);
 523
 524         if (!pseudoconstants)
 525                 return plan;
 526
 527         return (Plan *) make_result(root,
 528                                                                 plan->targetlist,
 529                                                                 (Node *) pseudoconstants,
 530                                                                 plan);
 531 }
 532
 533 /*
 534  * create_join_plan
 535  *        Create a join plan for 'best_path' and (recursively) plans for its
 536  *        inner and outer paths.
 537  */
 538 static Plan *
 539 create_join_plan(PlannerInfo *root, JoinPath *best_path)
 540 {
 541         Plan       *outer_plan;
 542         Plan       *inner_plan;
 543         Plan       *plan;
 544         Relids          saveOuterRels = root->curOuterRels;
 545
 546         outer_plan = create_plan_recurse(root, best_path->outerjoinpath);
 547
 548         /* For a nestloop, include outer relids in curOuterRels for inner side */
 549         if (best_path->path.pathtype == T_NestLoop)
 550                 root->curOuterRels = bms_union(root->curOuterRels,
 551                                                                    best_path->outerjoinpath->parent->relids);
 552
 553         inner_plan = create_plan_recurse(root, best_path->innerjoinpath);
 554
 555         switch (best_path->path.pathtype)
 556         {
 557                 case T_MergeJoin:
 558                         plan = (Plan *) create_mergejoin_plan(root,
 559                                                                                                   (MergePath *) best_path,
 560                                                                                                   outer_plan,
 561                                                                                                   inner_plan);
 562                         break;
 563                 case T_HashJoin:
 564                         plan = (Plan *) create_hashjoin_plan(root,
 565                                                                                                  (HashPath *) best_path,
 566                                                                                                  outer_plan,
 567                                                                                                  inner_plan);
 568                         break;
 569                 case T_NestLoop:
 570                         /* Restore curOuterRels */
 571                         bms_free(root->curOuterRels);
 572                         root->curOuterRels = saveOuterRels;
 573
 574                         plan = (Plan *) create_nestloop_plan(root,
 575                                                                                                  (NestPath *) best_path,
 576                                                                                                  outer_plan,
 577                                                                                                  inner_plan);
 578                         break;
 579                 default:
 580                         elog(ERROR, "unrecognized node type: %d",
 581                                  (int) best_path->path.pathtype);
 582                         plan = NULL;            /* keep compiler quiet */
 583                         break;
 584         }
 585
 586         /*
 587          * If there are any pseudoconstant clauses attached to this node, insert a
 588          * gating Result node that evaluates the pseudoconstants as one-time
 589          * quals.
 590          */
 591         if (root->hasPseudoConstantQuals)
 592                 plan = create_gating_plan(root, plan, best_path->joinrestrictinfo);
 593
 594 #ifdef NOT_USED
 595
 596         /*
 597          * * Expensive function pullups may have pulled local predicates * into
 598          * this path node.      Put them in the qpqual of the plan node. * JMH,
 599          * 6/15/92
 600          */
 601         if (get_loc_restrictinfo(best_path) != NIL)
 602                 set_qpqual((Plan) plan,
 603                                    list_concat(get_qpqual((Plan) plan),
 604                                            get_actual_clauses(get_loc_restrictinfo(best_path))));
 605 #endif
 606
 607         return plan;
 608 }
 609
 610 /*
 611  * create_append_plan
 612  *        Create an Append plan for 'best_path' and (recursively) plans
 613  *        for its subpaths.
 614  *
 615  *        Returns a Plan node.
 616  */
 617 static Plan *
 618 create_append_plan(PlannerInfo *root, AppendPath *best_path)
 619 {
 620         Append     *plan;
 621         List       *tlist = build_relation_tlist(best_path->path.parent);
 622         List       *subplans = NIL;
 623         ListCell   *subpaths;
 624
 625         /*
 626          * It is possible for the subplans list to contain only one entry, or even
 627          * no entries.  Handle these cases specially.
 628          *
 629          * XXX ideally, if there's just one entry, we'd not bother to generate an
 630          * Append node but just return the single child.  At the moment this does
 631          * not work because the varno of the child scan plan won't match the
 632          * parent-rel Vars it'll be asked to emit.
 633          */
 634         if (best_path->subpaths == NIL)
 635         {
 636                 /* Generate a Result plan with constant-FALSE gating qual */
 637                 return (Plan *) make_result(root,
 638                                                                         tlist,
 639                                                                         (Node *) list_make1(makeBoolConst(false,
 640                                                                                                                                           false)),
 641                                                                         NULL);
 642         }
 643
 644         /* Normal case with multiple subpaths */
 645         foreach(subpaths, best_path->subpaths)
 646         {
 647                 Path       *subpath = (Path *) lfirst(subpaths);
 648
 649                 subplans = lappend(subplans, create_plan_recurse(root, subpath));
 650         }
 651
 652         plan = make_append(subplans, tlist);
 653
 654         return (Plan *) plan;
 655 }
 656
 657 /*
 658  * create_merge_append_plan
 659  *        Create a MergeAppend plan for 'best_path' and (recursively) plans
 660  *        for its subpaths.
 661  *
 662  *        Returns a Plan node.
 663  */
 664 static Plan *
 665 create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
 666 {
 667         MergeAppend *node = makeNode(MergeAppend);
 668         Plan       *plan = &node->plan;
 669         List       *tlist = build_relation_tlist(best_path->path.parent);
 670         List       *pathkeys = best_path->path.pathkeys;
 671         List       *subplans = NIL;
 672         ListCell   *subpaths;
 673
 674         /*
 675          * We don't have the actual creation of the MergeAppend node split out
 676          * into a separate make_xxx function.  This is because we want to run
 677          * prepare_sort_from_pathkeys on it before we do so on the individual
 678          * child plans, to make cross-checking the sort info easier.
 679          */
 680         copy_path_costsize(plan, (Path *) best_path);
 681         plan->targetlist = tlist;
 682         plan->qual = NIL;
 683         plan->lefttree = NULL;
 684         plan->righttree = NULL;
 685
 686         /* Compute sort column info, and adjust MergeAppend's tlist as needed */
 687         (void) prepare_sort_from_pathkeys(root, plan, pathkeys,
 688                                                                           true,
 689                                                                           &node->numCols,
 690                                                                           &node->sortColIdx,
 691                                                                           &node->sortOperators,
 692                                                                           &node->collations,
 693                                                                           &node->nullsFirst);
 694
 695         /*
 696          * Now prepare the child plans.  We must apply prepare_sort_from_pathkeys
 697          * even to subplans that don't need an explicit sort, to make sure they
 698          * are returning the same sort key columns the MergeAppend expects.
 699          */
 700         foreach(subpaths, best_path->subpaths)
 701         {
 702                 Path       *subpath = (Path *) lfirst(subpaths);
 703                 Plan       *subplan;
 704                 int                     numsortkeys;
 705                 AttrNumber *sortColIdx;
 706                 Oid                *sortOperators;
 707                 Oid                *collations;
 708                 bool       *nullsFirst;
 709
 710                 /* Build the child plan */
 711                 subplan = create_plan_recurse(root, subpath);
 712
 713                 /* Compute sort column info, and adjust subplan's tlist as needed */
 714                 subplan = prepare_sort_from_pathkeys(root, subplan, pathkeys,
 715                                                                                          false,
 716                                                                                          &numsortkeys,
 717                                                                                          &sortColIdx,
 718                                                                                          &sortOperators,
 719                                                                                          &collations,
 720                                                                                          &nullsFirst);
 721
 722                 /*
 723                  * Check that we got the same sort key information.  We just Assert
 724                  * that the sortops match, since those depend only on the pathkeys;
 725                  * but it seems like a good idea to check the sort column numbers
 726                  * explicitly, to ensure the tlists really do match up.
 727                  */
 728                 Assert(numsortkeys == node->numCols);
 729                 if (memcmp(sortColIdx, node->sortColIdx,
 730                                    numsortkeys * sizeof(AttrNumber)) != 0)
 731                         elog(ERROR, "MergeAppend child's targetlist doesn't match MergeAppend");
 732                 Assert(memcmp(sortOperators, node->sortOperators,
 733                                           numsortkeys * sizeof(Oid)) == 0);
 734                 Assert(memcmp(collations, node->collations,
 735                                           numsortkeys * sizeof(Oid)) == 0);
 736                 Assert(memcmp(nullsFirst, node->nullsFirst,
 737                                           numsortkeys * sizeof(bool)) == 0);
 738
 739                 /* Now, insert a Sort node if subplan isn't sufficiently ordered */
 740                 if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
 741                         subplan = (Plan *) make_sort(root, subplan, numsortkeys,
 742                                                                                  sortColIdx, sortOperators,
 743                                                                                  collations, nullsFirst,
 744                                                                                  best_path->limit_tuples);
 745
 746                 subplans = lappend(subplans, subplan);
 747         }
 748
 749         node->mergeplans = subplans;
 750
 751         return (Plan *) node;
 752 }
 753
 754 /*
 755  * create_result_plan
 756  *        Create a Result plan for 'best_path'.
 757  *        This is only used for the case of a query with an empty jointree.
 758  *
 759  *        Returns a Plan node.
 760  */
 761 static Result *
 762 create_result_plan(PlannerInfo *root, ResultPath *best_path)
 763 {
 764         List       *tlist;
 765         List       *quals;
 766
 767         /* The tlist will be installed later, since we have no RelOptInfo */
 768         Assert(best_path->path.parent == NULL);
 769         tlist = NIL;
 770
 771         /* best_path->quals is just bare clauses */
 772
 773         quals = order_qual_clauses(root, best_path->quals);
 774
 775         return make_result(root, tlist, (Node *) quals, NULL);
 776 }
 777
 778 /*
 779  * create_material_plan
 780  *        Create a Material plan for 'best_path' and (recursively) plans
 781  *        for its subpaths.
 782  *
 783  *        Returns a Plan node.
 784  */
 785 static Material *
 786 create_material_plan(PlannerInfo *root, MaterialPath *best_path)
 787 {
 788         Material   *plan;
 789         Plan       *subplan;
 790
 791         subplan = create_plan_recurse(root, best_path->subpath);
 792
 793         /* We don't want any excess columns in the materialized tuples */
 794         disuse_physical_tlist(subplan, best_path->subpath);
 795
 796         plan = make_material(subplan);
 797
 798         copy_path_costsize(&plan->plan, (Path *) best_path);
 799
 800         return plan;
 801 }
 802
 803 /*
 804  * create_unique_plan
 805  *        Create a Unique plan for 'best_path' and (recursively) plans
 806  *        for its subpaths.
 807  *
 808  *        Returns a Plan node.
 809  */
 810 static Plan *
 811 create_unique_plan(PlannerInfo *root, UniquePath *best_path)
 812 {
 813         Plan       *plan;
 814         Plan       *subplan;
 815         List       *in_operators;
 816         List       *uniq_exprs;
 817         List       *newtlist;
 818         int                     nextresno;
 819         bool            newitems;
 820         int                     numGroupCols;
 821         AttrNumber *groupColIdx;
 822         int                     groupColPos;
 823         ListCell   *l;
 824
 825         subplan = create_plan_recurse(root, best_path->subpath);
 826
 827         /* Done if we don't need to do any actual unique-ifying */
 828         if (best_path->umethod == UNIQUE_PATH_NOOP)
 829                 return subplan;
 830
 831         /*
 832          * As constructed, the subplan has a "flat" tlist containing just the Vars
 833          * needed here and at upper levels.  The values we are supposed to
 834          * unique-ify may be expressions in these variables.  We have to add any
 835          * such expressions to the subplan's tlist.
 836          *
 837          * The subplan may have a "physical" tlist if it is a simple scan plan. If
 838          * we're going to sort, this should be reduced to the regular tlist, so
 839          * that we don't sort more data than we need to.  For hashing, the tlist
 840          * should be left as-is if we don't need to add any expressions; but if we
 841          * do have to add expressions, then a projection step will be needed at
 842          * runtime anyway, so we may as well remove unneeded items. Therefore
 843          * newtlist starts from build_relation_tlist() not just a copy of the
 844          * subplan's tlist; and we don't install it into the subplan unless we are
 845          * sorting or stuff has to be added.
 846          */
 847         in_operators = best_path->in_operators;
 848         uniq_exprs = best_path->uniq_exprs;
 849
 850         /* initialize modified subplan tlist as just the "required" vars */
 851         newtlist = build_relation_tlist(best_path->path.parent);
 852         nextresno = list_length(newtlist) + 1;
 853         newitems = false;
 854
 855         foreach(l, uniq_exprs)
 856         {
 857                 Node       *uniqexpr = lfirst(l);
 858                 TargetEntry *tle;
 859
 860                 tle = tlist_member(uniqexpr, newtlist);
 861                 if (!tle)
 862                 {
 863                         tle = makeTargetEntry((Expr *) uniqexpr,
 864                                                                   nextresno,
 865                                                                   NULL,
 866                                                                   false);
 867                         newtlist = lappend(newtlist, tle);
 868                         nextresno++;
 869                         newitems = true;
 870                 }
 871         }
 872
 873         if (newitems || best_path->umethod == UNIQUE_PATH_SORT)
 874         {
 875                 /*
 876                  * If the top plan node can't do projections, we need to add a Result
 877                  * node to help it along.
 878                  */
 879                 if (!is_projection_capable_plan(subplan))
 880                         subplan = (Plan *) make_result(root, newtlist, NULL, subplan);
 881                 else
 882                         subplan->targetlist = newtlist;
 883         }
 884
 885         /*
 886          * Build control information showing which subplan output columns are to
 887          * be examined by the grouping step.  Unfortunately we can't merge this
 888          * with the previous loop, since we didn't then know which version of the
 889          * subplan tlist we'd end up using.
 890          */
 891         newtlist = subplan->targetlist;
 892         numGroupCols = list_length(uniq_exprs);
 893         groupColIdx = (AttrNumber *) palloc(numGroupCols * sizeof(AttrNumber));
 894
 895         groupColPos = 0;
 896         foreach(l, uniq_exprs)
 897         {
 898                 Node       *uniqexpr = lfirst(l);
 899                 TargetEntry *tle;
 900
 901                 tle = tlist_member(uniqexpr, newtlist);
 902                 if (!tle)                               /* shouldn't happen */
 903                         elog(ERROR, "failed to find unique expression in subplan tlist");
 904                 groupColIdx[groupColPos++] = tle->resno;
 905         }
 906
 907         if (best_path->umethod == UNIQUE_PATH_HASH)
 908         {
 909                 long            numGroups;
 910                 Oid                *groupOperators;
 911
 912                 numGroups = (long) Min(best_path->rows, (double) LONG_MAX);
 913
 914                 /*
 915                  * Get the hashable equality operators for the Agg node to use.
 916                  * Normally these are the same as the IN clause operators, but if
 917                  * those are cross-type operators then the equality operators are the
 918                  * ones for the IN clause operators' RHS datatype.
 919                  */
 920                 groupOperators = (Oid *) palloc(numGroupCols * sizeof(Oid));
 921                 groupColPos = 0;
 922                 foreach(l, in_operators)
 923                 {
 924                         Oid                     in_oper = lfirst_oid(l);
 925                         Oid                     eq_oper;
 926
 927                         if (!get_compatible_hash_operators(in_oper, NULL, &eq_oper))
 928                                 elog(ERROR, "could not find compatible hash operator for operator %u",
 929                                          in_oper);
 930                         groupOperators[groupColPos++] = eq_oper;
 931                 }
 932
 933                 /*
 934                  * Since the Agg node is going to project anyway, we can give it the
 935                  * minimum output tlist, without any stuff we might have added to the
 936                  * subplan tlist.
 937                  */
 938                 plan = (Plan *) make_agg(root,
 939                                                                  build_relation_tlist(best_path->path.parent),
 940                                                                  NIL,
 941                                                                  AGG_HASHED,
 942                                                                  NULL,
 943                                                                  numGroupCols,
 944                                                                  groupColIdx,
 945                                                                  groupOperators,
 946                                                                  numGroups,
 947                                                                  subplan);
 948         }
 949         else
 950         {
 951                 List       *sortList = NIL;
 952
 953                 /* Create an ORDER BY list to sort the input compatibly */
 954                 groupColPos = 0;
 955                 foreach(l, in_operators)
 956                 {
 957                         Oid                     in_oper = lfirst_oid(l);
 958                         Oid                     sortop;
 959                         Oid                     eqop;
 960                         TargetEntry *tle;
 961                         SortGroupClause *sortcl;
 962
 963                         sortop = get_ordering_op_for_equality_op(in_oper, false);
 964                         if (!OidIsValid(sortop))        /* shouldn't happen */
 965                                 elog(ERROR, "could not find ordering operator for equality operator %u",
 966                                          in_oper);
 967
 968                         /*
 969                          * The Unique node will need equality operators.  Normally these
 970                          * are the same as the IN clause operators, but if those are
 971                          * cross-type operators then the equality operators are the ones
 972                          * for the IN clause operators' RHS datatype.
 973                          */
 974                         eqop = get_equality_op_for_ordering_op(sortop, NULL);
 975                         if (!OidIsValid(eqop))          /* shouldn't happen */
 976                                 elog(ERROR, "could not find equality operator for ordering operator %u",
 977                                          sortop);
 978
 979                         tle = get_tle_by_resno(subplan->targetlist,
 980                                                                    groupColIdx[groupColPos]);
 981                         Assert(tle != NULL);
 982
 983                         sortcl = makeNode(SortGroupClause);
 984                         sortcl->tleSortGroupRef = assignSortGroupRef(tle,
 985                                                                                                                  subplan->targetlist);
 986                         sortcl->eqop = eqop;
 987                         sortcl->sortop = sortop;
 988                         sortcl->nulls_first = false;
 989                         sortcl->hashable = false;       /* no need to make this accurate */
 990                         sortList = lappend(sortList, sortcl);
 991                         groupColPos++;
 992                 }
 993                 plan = (Plan *) make_sort_from_sortclauses(root, sortList, subplan);
 994                 plan = (Plan *) make_unique(plan, sortList);
 995         }
 996
 997         /* Adjust output size estimate (other fields should be OK already) */
 998         plan->plan_rows = best_path->rows;
 999
1000         return plan;
1001 }
1002
1003
1004 /*****************************************************************************
1005  *
1006  *      BASE-RELATION SCAN METHODS
1007  *
1008  *****************************************************************************/
1009
1010
1011 /*
1012  * create_seqscan_plan
1013  *       Returns a seqscan plan for the base relation scanned by 'best_path'
1014  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1015  */
1016 static SeqScan *
1017 create_seqscan_plan(PlannerInfo *root, Path *best_path,
1018                                         List *tlist, List *scan_clauses)
1019 {
1020         SeqScan    *scan_plan;
1021         Index           scan_relid = best_path->parent->relid;
1022
1023         /* it should be a base rel... */
1024         Assert(scan_relid > 0);
1025         Assert(best_path->parent->rtekind == RTE_RELATION);
1026
1027         /* Sort clauses into best execution order */
1028         scan_clauses = order_qual_clauses(root, scan_clauses);
1029
1030         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1031         scan_clauses = extract_actual_clauses(scan_clauses, false);
1032
1033         scan_plan = make_seqscan(tlist,
1034                                                          scan_clauses,
1035                                                          scan_relid);
1036
1037         copy_path_costsize(&scan_plan->plan, best_path);
1038
1039         return scan_plan;
1040 }
1041
1042 /*
1043  * create_indexscan_plan
1044  *        Returns an indexscan plan for the base relation scanned by 'best_path'
1045  *        with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1046  *
1047  * The indexquals list of the path contains implicitly-ANDed qual conditions.
1048  * The list can be empty --- then no index restrictions will be applied during
1049  * the scan.
1050  */
1051 static IndexScan *
1052 create_indexscan_plan(PlannerInfo *root,
1053                                           IndexPath *best_path,
1054                                           List *tlist,
1055                                           List *scan_clauses)
1056 {
1057         List       *indexquals = best_path->indexquals;
1058         List       *indexorderbys = best_path->indexorderbys;
1059         Index           baserelid = best_path->path.parent->relid;
1060         Oid                     indexoid = best_path->indexinfo->indexoid;
1061         List       *qpqual;
1062         List       *stripped_indexquals;
1063         List       *fixed_indexquals;
1064         List       *fixed_indexorderbys;
1065         ListCell   *l;
1066         IndexScan  *scan_plan;
1067
1068         /* it should be a base rel... */
1069         Assert(baserelid > 0);
1070         Assert(best_path->path.parent->rtekind == RTE_RELATION);
1071
1072         /*
1073          * Build "stripped" indexquals structure (no RestrictInfos) to pass to
1074          * executor as indexqualorig
1075          */
1076         stripped_indexquals = get_actual_clauses(indexquals);
1077
1078         /*
1079          * The executor needs a copy with the indexkey on the left of each clause
1080          * and with index attr numbers substituted for table ones.
1081          */
1082         fixed_indexquals = fix_indexqual_references(root, best_path, indexquals);
1083
1084         /*
1085          * Likewise fix up index attr references in the ORDER BY expressions.
1086          */
1087         fixed_indexorderbys = fix_indexorderby_references(root, best_path, indexorderbys);
1088
1089         /*
1090          * If this is an innerjoin scan, the indexclauses will contain join
1091          * clauses that are not present in scan_clauses (since the passed-in value
1092          * is just the rel's baserestrictinfo list).  We must add these clauses to
1093          * scan_clauses to ensure they get checked.  In most cases we will remove
1094          * the join clauses again below, but if a join clause contains a special
1095          * operator, we need to make sure it gets into the scan_clauses.
1096          *
1097          * Note: pointer comparison should be enough to determine RestrictInfo
1098          * matches.
1099          */
1100         if (best_path->isjoininner)
1101                 scan_clauses = list_union_ptr(scan_clauses, best_path->indexclauses);
1102
1103         /*
1104          * The qpqual list must contain all restrictions not automatically handled
1105          * by the index.  All the predicates in the indexquals will be checked
1106          * (either by the index itself, or by nodeIndexscan.c), but if there are
1107          * any "special" operators involved then they must be included in qpqual.
1108          * The upshot is that qpqual must contain scan_clauses minus whatever
1109          * appears in indexquals.
1110          *
1111          * In normal cases simple pointer equality checks will be enough to spot
1112          * duplicate RestrictInfos, so we try that first.  In some situations
1113          * (particularly with OR'd index conditions) we may have scan_clauses that
1114          * are not equal to, but are logically implied by, the index quals; so we
1115          * also try a predicate_implied_by() check to see if we can discard quals
1116          * that way.  (predicate_implied_by assumes its first input contains only
1117          * immutable functions, so we have to check that.)
1118          *
1119          * We can also discard quals that are implied by a partial index's
1120          * predicate, but only in a plain SELECT; when scanning a target relation
1121          * of UPDATE/DELETE/SELECT FOR UPDATE, we must leave such quals in the
1122          * plan so that they'll be properly rechecked by EvalPlanQual testing.
1123          */
1124         qpqual = NIL;
1125         foreach(l, scan_clauses)
1126         {
1127                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
1128
1129                 Assert(IsA(rinfo, RestrictInfo));
1130                 if (rinfo->pseudoconstant)
1131                         continue;                       /* we may drop pseudoconstants here */
1132                 if (list_member_ptr(indexquals, rinfo))
1133                         continue;
1134                 if (!contain_mutable_functions((Node *) rinfo->clause))
1135                 {
1136                         List       *clausel = list_make1(rinfo->clause);
1137
1138                         if (predicate_implied_by(clausel, indexquals))
1139                                 continue;
1140                         if (best_path->indexinfo->indpred)
1141                         {
1142                                 if (baserelid != root->parse->resultRelation &&
1143                                         get_parse_rowmark(root->parse, baserelid) == NULL)
1144                                         if (predicate_implied_by(clausel,
1145                                                                                          best_path->indexinfo->indpred))
1146                                                 continue;
1147                         }
1148                 }
1149                 qpqual = lappend(qpqual, rinfo);
1150         }
1151
1152         /* Sort clauses into best execution order */
1153         qpqual = order_qual_clauses(root, qpqual);
1154
1155         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1156         qpqual = extract_actual_clauses(qpqual, false);
1157
1158         /*
1159          * We have to replace any outer-relation variables with nestloop params in
1160          * the indexqualorig, qpqual, and indexorderbyorig expressions.  A bit
1161          * annoying to have to do this separately from the processing in
1162          * fix_indexqual_references --- rethink this when generalizing the inner
1163          * indexscan support.  But note we can't really do this earlier because
1164          * it'd break the comparisons to predicates above ... (or would it?  Those
1165          * wouldn't have outer refs)
1166          */
1167         if (best_path->isjoininner)
1168         {
1169                 stripped_indexquals = (List *)
1170                         replace_nestloop_params(root, (Node *) stripped_indexquals);
1171                 qpqual = (List *)
1172                         replace_nestloop_params(root, (Node *) qpqual);
1173                 indexorderbys = (List *)
1174                         replace_nestloop_params(root, (Node *) indexorderbys);
1175         }
1176
1177         /* Finally ready to build the plan node */
1178         scan_plan = make_indexscan(tlist,
1179                                                            qpqual,
1180                                                            baserelid,
1181                                                            indexoid,
1182                                                            fixed_indexquals,
1183                                                            stripped_indexquals,
1184                                                            fixed_indexorderbys,
1185                                                            indexorderbys,
1186                                                            best_path->indexscandir);
1187
1188         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1189         /* use the indexscan-specific rows estimate, not the parent rel's */
1190         scan_plan->scan.plan.plan_rows = best_path->rows;
1191
1192         return scan_plan;
1193 }
1194
1195 /*
1196  * create_bitmap_scan_plan
1197  *        Returns a bitmap scan plan for the base relation scanned by 'best_path'
1198  *        with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1199  */
1200 static BitmapHeapScan *
1201 create_bitmap_scan_plan(PlannerInfo *root,
1202                                                 BitmapHeapPath *best_path,
1203                                                 List *tlist,
1204                                                 List *scan_clauses)
1205 {
1206         Index           baserelid = best_path->path.parent->relid;
1207         Plan       *bitmapqualplan;
1208         List       *bitmapqualorig;
1209         List       *indexquals;
1210         List       *qpqual;
1211         ListCell   *l;
1212         BitmapHeapScan *scan_plan;
1213
1214         /* it should be a base rel... */
1215         Assert(baserelid > 0);
1216         Assert(best_path->path.parent->rtekind == RTE_RELATION);
1217
1218         /* Process the bitmapqual tree into a Plan tree and qual lists */
1219         bitmapqualplan = create_bitmap_subplan(root, best_path->bitmapqual,
1220                                                                                    &bitmapqualorig, &indexquals);
1221
1222         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1223         scan_clauses = extract_actual_clauses(scan_clauses, false);
1224
1225         /*
1226          * If this is a innerjoin scan, the indexclauses will contain join clauses
1227          * that are not present in scan_clauses (since the passed-in value is just
1228          * the rel's baserestrictinfo list).  We must add these clauses to
1229          * scan_clauses to ensure they get checked.  In most cases we will remove
1230          * the join clauses again below, but if a join clause contains a special
1231          * operator, we need to make sure it gets into the scan_clauses.
1232          */
1233         if (best_path->isjoininner)
1234         {
1235                 scan_clauses = list_concat_unique(scan_clauses, bitmapqualorig);
1236         }
1237
1238         /*
1239          * The qpqual list must contain all restrictions not automatically handled
1240          * by the index.  All the predicates in the indexquals will be checked
1241          * (either by the index itself, or by nodeBitmapHeapscan.c), but if there
1242          * are any "special" operators involved then they must be added to qpqual.
1243          * The upshot is that qpqual must contain scan_clauses minus whatever
1244          * appears in indexquals.
1245          *
1246          * In normal cases simple equal() checks will be enough to spot duplicate
1247          * clauses, so we try that first.  In some situations (particularly with
1248          * OR'd index conditions) we may have scan_clauses that are not equal to,
1249          * but are logically implied by, the index quals; so we also try a
1250          * predicate_implied_by() check to see if we can discard quals that way.
1251          * (predicate_implied_by assumes its first input contains only immutable
1252          * functions, so we have to check that.)
1253          *
1254          * Unlike create_indexscan_plan(), we need take no special thought here
1255          * for partial index predicates; this is because the predicate conditions
1256          * are already listed in bitmapqualorig and indexquals.  Bitmap scans have
1257          * to do it that way because predicate conditions need to be rechecked if
1258          * the scan becomes lossy.
1259          */
1260         qpqual = NIL;
1261         foreach(l, scan_clauses)
1262         {
1263                 Node       *clause = (Node *) lfirst(l);
1264
1265                 if (list_member(indexquals, clause))
1266                         continue;
1267                 if (!contain_mutable_functions(clause))
1268                 {
1269                         List       *clausel = list_make1(clause);
1270
1271                         if (predicate_implied_by(clausel, indexquals))
1272                                 continue;
1273                 }
1274                 qpqual = lappend(qpqual, clause);
1275         }
1276
1277         /* Sort clauses into best execution order */
1278         qpqual = order_qual_clauses(root, qpqual);
1279
1280         /*
1281          * When dealing with special operators, we will at this point have
1282          * duplicate clauses in qpqual and bitmapqualorig.      We may as well drop
1283          * 'em from bitmapqualorig, since there's no point in making the tests
1284          * twice.
1285          */
1286         bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual);
1287
1288         /* Finally ready to build the plan node */
1289         scan_plan = make_bitmap_heapscan(tlist,
1290                                                                          qpqual,
1291                                                                          bitmapqualplan,
1292                                                                          bitmapqualorig,
1293                                                                          baserelid);
1294
1295         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1296         /* use the indexscan-specific rows estimate, not the parent rel's */
1297         scan_plan->scan.plan.plan_rows = best_path->rows;
1298
1299         return scan_plan;
1300 }
1301
1302 /*
1303  * Given a bitmapqual tree, generate the Plan tree that implements it
1304  *
1305  * As byproducts, we also return in *qual and *indexqual the qual lists
1306  * (in implicit-AND form, without RestrictInfos) describing the original index
1307  * conditions and the generated indexqual conditions.  (These are the same in
1308  * simple cases, but when special index operators are involved, the former
1309  * list includes the special conditions while the latter includes the actual
1310  * indexable conditions derived from them.)  Both lists include partial-index
1311  * predicates, because we have to recheck predicates as well as index
1312  * conditions if the bitmap scan becomes lossy.
1313  *
1314  * Note: if you find yourself changing this, you probably need to change
1315  * make_restrictinfo_from_bitmapqual too.
1316  */
1317 static Plan *
1318 create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
1319                                           List **qual, List **indexqual)
1320 {
1321         Plan       *plan;
1322
1323         if (IsA(bitmapqual, BitmapAndPath))
1324         {
1325                 BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
1326                 List       *subplans = NIL;
1327                 List       *subquals = NIL;
1328                 List       *subindexquals = NIL;
1329                 ListCell   *l;
1330
1331                 /*
1332                  * There may well be redundant quals among the subplans, since a
1333                  * top-level WHERE qual might have gotten used to form several
1334                  * different index quals.  We don't try exceedingly hard to eliminate
1335                  * redundancies, but we do eliminate obvious duplicates by using
1336                  * list_concat_unique.
1337                  */
1338                 foreach(l, apath->bitmapquals)
1339                 {
1340                         Plan       *subplan;
1341                         List       *subqual;
1342                         List       *subindexqual;
1343
1344                         subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
1345                                                                                         &subqual, &subindexqual);
1346                         subplans = lappend(subplans, subplan);
1347                         subquals = list_concat_unique(subquals, subqual);
1348                         subindexquals = list_concat_unique(subindexquals, subindexqual);
1349                 }
1350                 plan = (Plan *) make_bitmap_and(subplans);
1351                 plan->startup_cost = apath->path.startup_cost;
1352                 plan->total_cost = apath->path.total_cost;
1353                 plan->plan_rows =
1354                         clamp_row_est(apath->bitmapselectivity * apath->path.parent->tuples);
1355                 plan->plan_width = 0;   /* meaningless */
1356                 *qual = subquals;
1357                 *indexqual = subindexquals;
1358         }
1359         else if (IsA(bitmapqual, BitmapOrPath))
1360         {
1361                 BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
1362                 List       *subplans = NIL;
1363                 List       *subquals = NIL;
1364                 List       *subindexquals = NIL;
1365                 bool            const_true_subqual = false;
1366                 bool            const_true_subindexqual = false;
1367                 ListCell   *l;
1368
1369                 /*
1370                  * Here, we only detect qual-free subplans.  A qual-free subplan would
1371                  * cause us to generate "... OR true ..."  which we may as well reduce
1372                  * to just "true".      We do not try to eliminate redundant subclauses
1373                  * because (a) it's not as likely as in the AND case, and (b) we might
1374                  * well be working with hundreds or even thousands of OR conditions,
1375                  * perhaps from a long IN list.  The performance of list_append_unique
1376                  * would be unacceptable.
1377                  */
1378                 foreach(l, opath->bitmapquals)
1379                 {
1380                         Plan       *subplan;
1381                         List       *subqual;
1382                         List       *subindexqual;
1383
1384                         subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
1385                                                                                         &subqual, &subindexqual);
1386                         subplans = lappend(subplans, subplan);
1387                         if (subqual == NIL)
1388                                 const_true_subqual = true;
1389                         else if (!const_true_subqual)
1390                                 subquals = lappend(subquals,
1391                                                                    make_ands_explicit(subqual));
1392                         if (subindexqual == NIL)
1393                                 const_true_subindexqual = true;
1394                         else if (!const_true_subindexqual)
1395                                 subindexquals = lappend(subindexquals,
1396                                                                                 make_ands_explicit(subindexqual));
1397                 }
1398
1399                 /*
1400                  * In the presence of ScalarArrayOpExpr quals, we might have built
1401                  * BitmapOrPaths with just one subpath; don't add an OR step.
1402                  */
1403                 if (list_length(subplans) == 1)
1404                 {
1405                         plan = (Plan *) linitial(subplans);
1406                 }
1407                 else
1408                 {
1409                         plan = (Plan *) make_bitmap_or(subplans);
1410                         plan->startup_cost = opath->path.startup_cost;
1411                         plan->total_cost = opath->path.total_cost;
1412                         plan->plan_rows =
1413                                 clamp_row_est(opath->bitmapselectivity * opath->path.parent->tuples);
1414                         plan->plan_width = 0;           /* meaningless */
1415                 }
1416
1417                 /*
1418                  * If there were constant-TRUE subquals, the OR reduces to constant
1419                  * TRUE.  Also, avoid generating one-element ORs, which could happen
1420                  * due to redundancy elimination or ScalarArrayOpExpr quals.
1421                  */
1422                 if (const_true_subqual)
1423                         *qual = NIL;
1424                 else if (list_length(subquals) <= 1)
1425                         *qual = subquals;
1426                 else
1427                         *qual = list_make1(make_orclause(subquals));
1428                 if (const_true_subindexqual)
1429                         *indexqual = NIL;
1430                 else if (list_length(subindexquals) <= 1)
1431                         *indexqual = subindexquals;
1432                 else
1433                         *indexqual = list_make1(make_orclause(subindexquals));
1434         }
1435         else if (IsA(bitmapqual, IndexPath))
1436         {
1437                 IndexPath  *ipath = (IndexPath *) bitmapqual;
1438                 IndexScan  *iscan;
1439                 ListCell   *l;
1440
1441                 /* Use the regular indexscan plan build machinery... */
1442                 iscan = create_indexscan_plan(root, ipath, NIL, NIL);
1443                 /* then convert to a bitmap indexscan */
1444                 plan = (Plan *) make_bitmap_indexscan(iscan->scan.scanrelid,
1445                                                                                           iscan->indexid,
1446                                                                                           iscan->indexqual,
1447                                                                                           iscan->indexqualorig);
1448                 plan->startup_cost = 0.0;
1449                 plan->total_cost = ipath->indextotalcost;
1450                 plan->plan_rows =
1451                         clamp_row_est(ipath->indexselectivity * ipath->path.parent->tuples);
1452                 plan->plan_width = 0;   /* meaningless */
1453                 *qual = get_actual_clauses(ipath->indexclauses);
1454                 *indexqual = get_actual_clauses(ipath->indexquals);
1455                 foreach(l, ipath->indexinfo->indpred)
1456                 {
1457                         Expr       *pred = (Expr *) lfirst(l);
1458
1459                         /*
1460                          * We know that the index predicate must have been implied by the
1461                          * query condition as a whole, but it may or may not be implied by
1462                          * the conditions that got pushed into the bitmapqual.  Avoid
1463                          * generating redundant conditions.
1464                          */
1465                         if (!predicate_implied_by(list_make1(pred), ipath->indexclauses))
1466                         {
1467                                 *qual = lappend(*qual, pred);
1468                                 *indexqual = lappend(*indexqual, pred);
1469                         }
1470                 }
1471
1472                 /*
1473                  * Replace outer-relation variables with nestloop params, but only
1474                  * after doing the above comparisons to index predicates.
1475                  */
1476                 if (ipath->isjoininner)
1477                 {
1478                         *qual = (List *)
1479                                 replace_nestloop_params(root, (Node *) *qual);
1480                         *indexqual = (List *)
1481                                 replace_nestloop_params(root, (Node *) *indexqual);
1482                 }
1483         }
1484         else
1485         {
1486                 elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
1487                 plan = NULL;                    /* keep compiler quiet */
1488         }
1489
1490         return plan;
1491 }
1492
1493 /*
1494  * create_tidscan_plan
1495  *       Returns a tidscan plan for the base relation scanned by 'best_path'
1496  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1497  */
1498 static TidScan *
1499 create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
1500                                         List *tlist, List *scan_clauses)
1501 {
1502         TidScan    *scan_plan;
1503         Index           scan_relid = best_path->path.parent->relid;
1504         List       *ortidquals;
1505
1506         /* it should be a base rel... */
1507         Assert(scan_relid > 0);
1508         Assert(best_path->path.parent->rtekind == RTE_RELATION);
1509
1510         /* Sort clauses into best execution order */
1511         scan_clauses = order_qual_clauses(root, scan_clauses);
1512
1513         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1514         scan_clauses = extract_actual_clauses(scan_clauses, false);
1515
1516         /*
1517          * Remove any clauses that are TID quals.  This is a bit tricky since the
1518          * tidquals list has implicit OR semantics.
1519          */
1520         ortidquals = best_path->tidquals;
1521         if (list_length(ortidquals) > 1)
1522                 ortidquals = list_make1(make_orclause(ortidquals));
1523         scan_clauses = list_difference(scan_clauses, ortidquals);
1524
1525         scan_plan = make_tidscan(tlist,
1526                                                          scan_clauses,
1527                                                          scan_relid,
1528                                                          best_path->tidquals);
1529
1530         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1531
1532         return scan_plan;
1533 }
1534
1535 /*
1536  * create_subqueryscan_plan
1537  *       Returns a subqueryscan plan for the base relation scanned by 'best_path'
1538  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1539  */
1540 static SubqueryScan *
1541 create_subqueryscan_plan(PlannerInfo *root, Path *best_path,
1542                                                  List *tlist, List *scan_clauses)
1543 {
1544         SubqueryScan *scan_plan;
1545         Index           scan_relid = best_path->parent->relid;
1546
1547         /* it should be a subquery base rel... */
1548         Assert(scan_relid > 0);
1549         Assert(best_path->parent->rtekind == RTE_SUBQUERY);
1550
1551         /* Sort clauses into best execution order */
1552         scan_clauses = order_qual_clauses(root, scan_clauses);
1553
1554         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1555         scan_clauses = extract_actual_clauses(scan_clauses, false);
1556
1557         scan_plan = make_subqueryscan(tlist,
1558                                                                   scan_clauses,
1559                                                                   scan_relid,
1560                                                                   best_path->parent->subplan);
1561
1562         copy_path_costsize(&scan_plan->scan.plan, best_path);
1563
1564         return scan_plan;
1565 }
1566
1567 /*
1568  * create_functionscan_plan
1569  *       Returns a functionscan plan for the base relation scanned by 'best_path'
1570  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1571  */
1572 static FunctionScan *
1573 create_functionscan_plan(PlannerInfo *root, Path *best_path,
1574                                                  List *tlist, List *scan_clauses)
1575 {
1576         FunctionScan *scan_plan;
1577         Index           scan_relid = best_path->parent->relid;
1578         RangeTblEntry *rte;
1579
1580         /* it should be a function base rel... */
1581         Assert(scan_relid > 0);
1582         rte = planner_rt_fetch(scan_relid, root);
1583         Assert(rte->rtekind == RTE_FUNCTION);
1584
1585         /* Sort clauses into best execution order */
1586         scan_clauses = order_qual_clauses(root, scan_clauses);
1587
1588         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1589         scan_clauses = extract_actual_clauses(scan_clauses, false);
1590
1591         scan_plan = make_functionscan(tlist, scan_clauses, scan_relid,
1592                                                                   rte->funcexpr,
1593                                                                   rte->eref->colnames,
1594                                                                   rte->funccoltypes,
1595                                                                   rte->funccoltypmods,
1596                                                                   rte->funccolcollations);
1597
1598         copy_path_costsize(&scan_plan->scan.plan, best_path);
1599
1600         return scan_plan;
1601 }
1602
1603 /*
1604  * create_valuesscan_plan
1605  *       Returns a valuesscan plan for the base relation scanned by 'best_path'
1606  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1607  */
1608 static ValuesScan *
1609 create_valuesscan_plan(PlannerInfo *root, Path *best_path,
1610                                            List *tlist, List *scan_clauses)
1611 {
1612         ValuesScan *scan_plan;
1613         Index           scan_relid = best_path->parent->relid;
1614         RangeTblEntry *rte;
1615
1616         /* it should be a values base rel... */
1617         Assert(scan_relid > 0);
1618         rte = planner_rt_fetch(scan_relid, root);
1619         Assert(rte->rtekind == RTE_VALUES);
1620
1621         /* Sort clauses into best execution order */
1622         scan_clauses = order_qual_clauses(root, scan_clauses);
1623
1624         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1625         scan_clauses = extract_actual_clauses(scan_clauses, false);
1626
1627         scan_plan = make_valuesscan(tlist, scan_clauses, scan_relid,
1628                                                                 rte->values_lists);
1629
1630         copy_path_costsize(&scan_plan->scan.plan, best_path);
1631
1632         return scan_plan;
1633 }
1634
1635 /*
1636  * create_ctescan_plan
1637  *       Returns a ctescan plan for the base relation scanned by 'best_path'
1638  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1639  */
1640 static CteScan *
1641 create_ctescan_plan(PlannerInfo *root, Path *best_path,
1642                                         List *tlist, List *scan_clauses)
1643 {
1644         CteScan    *scan_plan;
1645         Index           scan_relid = best_path->parent->relid;
1646         RangeTblEntry *rte;
1647         SubPlan    *ctesplan = NULL;
1648         int                     plan_id;
1649         int                     cte_param_id;
1650         PlannerInfo *cteroot;
1651         Index           levelsup;
1652         int                     ndx;
1653         ListCell   *lc;
1654
1655         Assert(scan_relid > 0);
1656         rte = planner_rt_fetch(scan_relid, root);
1657         Assert(rte->rtekind == RTE_CTE);
1658         Assert(!rte->self_reference);
1659
1660         /*
1661          * Find the referenced CTE, and locate the SubPlan previously made for it.
1662          */
1663         levelsup = rte->ctelevelsup;
1664         cteroot = root;
1665         while (levelsup-- > 0)
1666         {
1667                 cteroot = cteroot->parent_root;
1668                 if (!cteroot)                   /* shouldn't happen */
1669                         elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1670         }
1671
1672         /*
1673          * Note: cte_plan_ids can be shorter than cteList, if we are still working
1674          * on planning the CTEs (ie, this is a side-reference from another CTE).
1675          * So we mustn't use forboth here.
1676          */
1677         ndx = 0;
1678         foreach(lc, cteroot->parse->cteList)
1679         {
1680                 CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
1681
1682                 if (strcmp(cte->ctename, rte->ctename) == 0)
1683                         break;
1684                 ndx++;
1685         }
1686         if (lc == NULL)                         /* shouldn't happen */
1687                 elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
1688         if (ndx >= list_length(cteroot->cte_plan_ids))
1689                 elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
1690         plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
1691         Assert(plan_id > 0);
1692         foreach(lc, cteroot->init_plans)
1693         {
1694                 ctesplan = (SubPlan *) lfirst(lc);
1695                 if (ctesplan->plan_id == plan_id)
1696                         break;
1697         }
1698         if (lc == NULL)                         /* shouldn't happen */
1699                 elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
1700
1701         /*
1702          * We need the CTE param ID, which is the sole member of the SubPlan's
1703          * setParam list.
1704          */
1705         cte_param_id = linitial_int(ctesplan->setParam);
1706
1707         /* Sort clauses into best execution order */
1708         scan_clauses = order_qual_clauses(root, scan_clauses);
1709
1710         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1711         scan_clauses = extract_actual_clauses(scan_clauses, false);
1712
1713         scan_plan = make_ctescan(tlist, scan_clauses, scan_relid,
1714                                                          plan_id, cte_param_id);
1715
1716         copy_path_costsize(&scan_plan->scan.plan, best_path);
1717
1718         return scan_plan;
1719 }
1720
1721 /*
1722  * create_worktablescan_plan
1723  *       Returns a worktablescan plan for the base relation scanned by 'best_path'
1724  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1725  */
1726 static WorkTableScan *
1727 create_worktablescan_plan(PlannerInfo *root, Path *best_path,
1728                                                   List *tlist, List *scan_clauses)
1729 {
1730         WorkTableScan *scan_plan;
1731         Index           scan_relid = best_path->parent->relid;
1732         RangeTblEntry *rte;
1733         Index           levelsup;
1734         PlannerInfo *cteroot;
1735
1736         Assert(scan_relid > 0);
1737         rte = planner_rt_fetch(scan_relid, root);
1738         Assert(rte->rtekind == RTE_CTE);
1739         Assert(rte->self_reference);
1740
1741         /*
1742          * We need to find the worktable param ID, which is in the plan level
1743          * that's processing the recursive UNION, which is one level *below* where
1744          * the CTE comes from.
1745          */
1746         levelsup = rte->ctelevelsup;
1747         if (levelsup == 0)                      /* shouldn't happen */
1748                 elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1749         levelsup--;
1750         cteroot = root;
1751         while (levelsup-- > 0)
1752         {
1753                 cteroot = cteroot->parent_root;
1754                 if (!cteroot)                   /* shouldn't happen */
1755                         elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1756         }
1757         if (cteroot->wt_param_id < 0)           /* shouldn't happen */
1758                 elog(ERROR, "could not find param ID for CTE \"%s\"", rte->ctename);
1759
1760         /* Sort clauses into best execution order */
1761         scan_clauses = order_qual_clauses(root, scan_clauses);
1762
1763         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1764         scan_clauses = extract_actual_clauses(scan_clauses, false);
1765
1766         scan_plan = make_worktablescan(tlist, scan_clauses, scan_relid,
1767                                                                    cteroot->wt_param_id);
1768
1769         copy_path_costsize(&scan_plan->scan.plan, best_path);
1770
1771         return scan_plan;
1772 }
1773
1774 /*
1775  * create_foreignscan_plan
1776  *       Returns a foreignscan plan for the base relation scanned by 'best_path'
1777  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1778  */
1779 static ForeignScan *
1780 create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
1781                                                 List *tlist, List *scan_clauses)
1782 {
1783         ForeignScan *scan_plan;
1784         RelOptInfo *rel = best_path->path.parent;
1785         Index           scan_relid = rel->relid;
1786         RangeTblEntry *rte;
1787         bool            fsSystemCol;
1788         int                     i;
1789
1790         /* it should be a base rel... */
1791         Assert(scan_relid > 0);
1792         Assert(rel->rtekind == RTE_RELATION);
1793         rte = planner_rt_fetch(scan_relid, root);
1794         Assert(rte->rtekind == RTE_RELATION);
1795
1796         /* Sort clauses into best execution order */
1797         scan_clauses = order_qual_clauses(root, scan_clauses);
1798
1799         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1800         scan_clauses = extract_actual_clauses(scan_clauses, false);
1801
1802         /* Detect whether any system columns are requested from rel */
1803         fsSystemCol = false;
1804         for (i = rel->min_attr; i < 0; i++)
1805         {
1806                 if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
1807                 {
1808                         fsSystemCol = true;
1809                         break;
1810                 }
1811         }
1812
1813         scan_plan = make_foreignscan(tlist,
1814                                                                  scan_clauses,
1815                                                                  scan_relid,
1816                                                                  fsSystemCol,
1817                                                                  best_path->fdwplan);
1818
1819         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1820
1821         return scan_plan;
1822 }
1823
1824
1825 /*****************************************************************************
1826  *
1827  *      JOIN METHODS
1828  *
1829  *****************************************************************************/
1830
1831 static NestLoop *
1832 create_nestloop_plan(PlannerInfo *root,
1833                                          NestPath *best_path,
1834                                          Plan *outer_plan,
1835                                          Plan *inner_plan)
1836 {
1837         NestLoop   *join_plan;
1838         List       *tlist = build_relation_tlist(best_path->path.parent);
1839         List       *joinrestrictclauses = best_path->joinrestrictinfo;
1840         List       *joinclauses;
1841         List       *otherclauses;
1842         Relids          outerrelids;
1843         List       *nestParams;
1844         ListCell   *cell;
1845         ListCell   *prev;
1846         ListCell   *next;
1847
1848         /*
1849          * If the inner path is a nestloop inner indexscan, it might be using some
1850          * of the join quals as index quals, in which case we don't have to check
1851          * them again at the join node.  Remove any join quals that are redundant.
1852          */
1853         joinrestrictclauses =
1854                 select_nonredundant_join_clauses(root,
1855                                                                                  joinrestrictclauses,
1856                                                                                  best_path->innerjoinpath);
1857
1858         /* Sort join qual clauses into best execution order */
1859         joinrestrictclauses = order_qual_clauses(root, joinrestrictclauses);
1860
1861         /* Get the join qual clauses (in plain expression form) */
1862         /* Any pseudoconstant clauses are ignored here */
1863         if (IS_OUTER_JOIN(best_path->jointype))
1864         {
1865                 extract_actual_join_clauses(joinrestrictclauses,
1866                                                                         &joinclauses, &otherclauses);
1867         }
1868         else
1869         {
1870                 /* We can treat all clauses alike for an inner join */
1871                 joinclauses = extract_actual_clauses(joinrestrictclauses, false);
1872                 otherclauses = NIL;
1873         }
1874
1875         /*
1876          * Identify any nestloop parameters that should be supplied by this join
1877          * node, and move them from root->curOuterParams to the nestParams list.
1878          */
1879         outerrelids = best_path->outerjoinpath->parent->relids;
1880         nestParams = NIL;
1881         prev = NULL;
1882         for (cell = list_head(root->curOuterParams); cell; cell = next)
1883         {
1884                 NestLoopParam *nlp = (NestLoopParam *) lfirst(cell);
1885
1886                 next = lnext(cell);
1887                 if (bms_is_member(nlp->paramval->varno, outerrelids))
1888                 {
1889                         root->curOuterParams = list_delete_cell(root->curOuterParams,
1890                                                                                                         cell, prev);
1891                         nestParams = lappend(nestParams, nlp);
1892                 }
1893                 else
1894                         prev = cell;
1895         }
1896
1897         join_plan = make_nestloop(tlist,
1898                                                           joinclauses,
1899                                                           otherclauses,
1900                                                           nestParams,
1901                                                           outer_plan,
1902                                                           inner_plan,
1903                                                           best_path->jointype);
1904
1905         copy_path_costsize(&join_plan->join.plan, &best_path->path);
1906
1907         return join_plan;
1908 }
1909
1910 static MergeJoin *
1911 create_mergejoin_plan(PlannerInfo *root,
1912                                           MergePath *best_path,
1913                                           Plan *outer_plan,
1914                                           Plan *inner_plan)
1915 {
1916         List       *tlist = build_relation_tlist(best_path->jpath.path.parent);
1917         List       *joinclauses;
1918         List       *otherclauses;
1919         List       *mergeclauses;
1920         List       *outerpathkeys;
1921         List       *innerpathkeys;
1922         int                     nClauses;
1923         Oid                *mergefamilies;
1924         Oid                *mergecollations;
1925         int                *mergestrategies;
1926         bool       *mergenullsfirst;
1927         MergeJoin  *join_plan;
1928         int                     i;
1929         ListCell   *lc;
1930         ListCell   *lop;
1931         ListCell   *lip;
1932
1933         /* Sort join qual clauses into best execution order */
1934         /* NB: do NOT reorder the mergeclauses */
1935         joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
1936
1937         /* Get the join qual clauses (in plain expression form) */
1938         /* Any pseudoconstant clauses are ignored here */
1939         if (IS_OUTER_JOIN(best_path->jpath.jointype))
1940         {
1941                 extract_actual_join_clauses(joinclauses,
1942                                                                         &joinclauses, &otherclauses);
1943         }
1944         else
1945         {
1946                 /* We can treat all clauses alike for an inner join */
1947                 joinclauses = extract_actual_clauses(joinclauses, false);
1948                 otherclauses = NIL;
1949         }
1950
1951         /*
1952          * Remove the mergeclauses from the list of join qual clauses, leaving the
1953          * list of quals that must be checked as qpquals.
1954          */
1955         mergeclauses = get_actual_clauses(best_path->path_mergeclauses);
1956         joinclauses = list_difference(joinclauses, mergeclauses);
1957
1958         /*
1959          * Rearrange mergeclauses, if needed, so that the outer variable is always
1960          * on the left; mark the mergeclause restrictinfos with correct
1961          * outer_is_left status.
1962          */
1963         mergeclauses = get_switched_clauses(best_path->path_mergeclauses,
1964                                                          best_path->jpath.outerjoinpath->parent->relids);
1965
1966         /*
1967          * Create explicit sort nodes for the outer and inner paths if necessary.
1968          * Make sure there are no excess columns in the inputs if sorting.
1969          */
1970         if (best_path->outersortkeys)
1971         {
1972                 disuse_physical_tlist(outer_plan, best_path->jpath.outerjoinpath);
1973                 outer_plan = (Plan *)
1974                         make_sort_from_pathkeys(root,
1975                                                                         outer_plan,
1976                                                                         best_path->outersortkeys,
1977                                                                         -1.0);
1978                 outerpathkeys = best_path->outersortkeys;
1979         }
1980         else
1981                 outerpathkeys = best_path->jpath.outerjoinpath->pathkeys;
1982
1983         if (best_path->innersortkeys)
1984         {
1985                 disuse_physical_tlist(inner_plan, best_path->jpath.innerjoinpath);
1986                 inner_plan = (Plan *)
1987                         make_sort_from_pathkeys(root,
1988                                                                         inner_plan,
1989                                                                         best_path->innersortkeys,
1990                                                                         -1.0);
1991                 innerpathkeys = best_path->innersortkeys;
1992         }
1993         else
1994                 innerpathkeys = best_path->jpath.innerjoinpath->pathkeys;
1995
1996         /*
1997          * If specified, add a materialize node to shield the inner plan from the
1998          * need to handle mark/restore.
1999          */
2000         if (best_path->materialize_inner)
2001         {
2002                 Plan       *matplan = (Plan *) make_material(inner_plan);
2003
2004                 /*
2005                  * We assume the materialize will not spill to disk, and therefore
2006                  * charge just cpu_operator_cost per tuple.  (Keep this estimate in
2007                  * sync with cost_mergejoin.)
2008                  */
2009                 copy_plan_costsize(matplan, inner_plan);
2010                 matplan->total_cost += cpu_operator_cost * matplan->plan_rows;
2011
2012                 inner_plan = matplan;
2013         }
2014
2015         /*
2016          * Compute the opfamily/collation/strategy/nullsfirst arrays needed by the
2017          * executor.  The information is in the pathkeys for the two inputs, but
2018          * we need to be careful about the possibility of mergeclauses sharing a
2019          * pathkey (compare find_mergeclauses_for_pathkeys()).
2020          */
2021         nClauses = list_length(mergeclauses);
2022         Assert(nClauses == list_length(best_path->path_mergeclauses));
2023         mergefamilies = (Oid *) palloc(nClauses * sizeof(Oid));
2024         mergecollations = (Oid *) palloc(nClauses * sizeof(Oid));
2025         mergestrategies = (int *) palloc(nClauses * sizeof(int));
2026         mergenullsfirst = (bool *) palloc(nClauses * sizeof(bool));
2027
2028         lop = list_head(outerpathkeys);
2029         lip = list_head(innerpathkeys);
2030         i = 0;
2031         foreach(lc, best_path->path_mergeclauses)
2032         {
2033                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2034                 EquivalenceClass *oeclass;
2035                 EquivalenceClass *ieclass;
2036                 PathKey    *opathkey;
2037                 PathKey    *ipathkey;
2038                 EquivalenceClass *opeclass;
2039                 EquivalenceClass *ipeclass;
2040                 ListCell   *l2;
2041
2042                 /* fetch outer/inner eclass from mergeclause */
2043                 Assert(IsA(rinfo, RestrictInfo));
2044                 if (rinfo->outer_is_left)
2045                 {
2046                         oeclass = rinfo->left_ec;
2047                         ieclass = rinfo->right_ec;
2048                 }
2049                 else
2050                 {
2051                         oeclass = rinfo->right_ec;
2052                         ieclass = rinfo->left_ec;
2053                 }
2054                 Assert(oeclass != NULL);
2055                 Assert(ieclass != NULL);
2056
2057                 /*
2058                  * For debugging purposes, we check that the eclasses match the paths'
2059                  * pathkeys.  In typical cases the merge clauses are one-to-one with
2060                  * the pathkeys, but when dealing with partially redundant query
2061                  * conditions, we might have clauses that re-reference earlier path
2062                  * keys.  The case that we need to reject is where a pathkey is
2063                  * entirely skipped over.
2064                  *
2065                  * lop and lip reference the first as-yet-unused pathkey elements;
2066                  * it's okay to match them, or any element before them.  If they're
2067                  * NULL then we have found all pathkey elements to be used.
2068                  */
2069                 if (lop)
2070                 {
2071                         opathkey = (PathKey *) lfirst(lop);
2072                         opeclass = opathkey->pk_eclass;
2073                         if (oeclass == opeclass)
2074                         {
2075                                 /* fast path for typical case */
2076                                 lop = lnext(lop);
2077                         }
2078                         else
2079                         {
2080                                 /* redundant clauses ... must match something before lop */
2081                                 foreach(l2, outerpathkeys)
2082                                 {
2083                                         if (l2 == lop)
2084                                                 break;
2085                                         opathkey = (PathKey *) lfirst(l2);
2086                                         opeclass = opathkey->pk_eclass;
2087                                         if (oeclass == opeclass)
2088                                                 break;
2089                                 }
2090                                 if (oeclass != opeclass)
2091                                         elog(ERROR, "outer pathkeys do not match mergeclauses");
2092                         }
2093                 }
2094                 else
2095                 {
2096                         /* redundant clauses ... must match some already-used pathkey */
2097                         opathkey = NULL;
2098                         opeclass = NULL;
2099                         foreach(l2, outerpathkeys)
2100                         {
2101                                 opathkey = (PathKey *) lfirst(l2);
2102                                 opeclass = opathkey->pk_eclass;
2103                                 if (oeclass == opeclass)
2104                                         break;
2105                         }
2106                         if (l2 == NULL)
2107                                 elog(ERROR, "outer pathkeys do not match mergeclauses");
2108                 }
2109
2110                 if (lip)
2111                 {
2112                         ipathkey = (PathKey *) lfirst(lip);
2113                         ipeclass = ipathkey->pk_eclass;
2114                         if (ieclass == ipeclass)
2115                         {
2116                                 /* fast path for typical case */
2117                                 lip = lnext(lip);
2118                         }
2119                         else
2120                         {
2121                                 /* redundant clauses ... must match something before lip */
2122                                 foreach(l2, innerpathkeys)
2123                                 {
2124                                         if (l2 == lip)
2125                                                 break;
2126                                         ipathkey = (PathKey *) lfirst(l2);
2127                                         ipeclass = ipathkey->pk_eclass;
2128                                         if (ieclass == ipeclass)
2129                                                 break;
2130                                 }
2131                                 if (ieclass != ipeclass)
2132                                         elog(ERROR, "inner pathkeys do not match mergeclauses");
2133                         }
2134                 }
2135                 else
2136                 {
2137                         /* redundant clauses ... must match some already-used pathkey */
2138                         ipathkey = NULL;
2139                         ipeclass = NULL;
2140                         foreach(l2, innerpathkeys)
2141                         {
2142                                 ipathkey = (PathKey *) lfirst(l2);
2143                                 ipeclass = ipathkey->pk_eclass;
2144                                 if (ieclass == ipeclass)
2145                                         break;
2146                         }
2147                         if (l2 == NULL)
2148                                 elog(ERROR, "inner pathkeys do not match mergeclauses");
2149                 }
2150
2151                 /* pathkeys should match each other too (more debugging) */
2152                 if (opathkey->pk_opfamily != ipathkey->pk_opfamily ||
2153                         opathkey->pk_eclass->ec_collation != ipathkey->pk_eclass->ec_collation ||
2154                         opathkey->pk_strategy != ipathkey->pk_strategy ||
2155                         opathkey->pk_nulls_first != ipathkey->pk_nulls_first)
2156                         elog(ERROR, "left and right pathkeys do not match in mergejoin");
2157
2158                 /* OK, save info for executor */
2159                 mergefamilies[i] = opathkey->pk_opfamily;
2160                 mergecollations[i] = opathkey->pk_eclass->ec_collation;
2161                 mergestrategies[i] = opathkey->pk_strategy;
2162                 mergenullsfirst[i] = opathkey->pk_nulls_first;
2163                 i++;
2164         }
2165
2166         /*
2167          * Note: it is not an error if we have additional pathkey elements (i.e.,
2168          * lop or lip isn't NULL here).  The input paths might be better-sorted
2169          * than we need for the current mergejoin.
2170          */
2171
2172         /*
2173          * Now we can build the mergejoin node.
2174          */
2175         join_plan = make_mergejoin(tlist,
2176                                                            joinclauses,
2177                                                            otherclauses,
2178                                                            mergeclauses,
2179                                                            mergefamilies,
2180                                                            mergecollations,
2181                                                            mergestrategies,
2182                                                            mergenullsfirst,
2183                                                            outer_plan,
2184                                                            inner_plan,
2185                                                            best_path->jpath.jointype);
2186
2187         /* Costs of sort and material steps are included in path cost already */
2188         copy_path_costsize(&join_plan->join.plan, &best_path->jpath.path);
2189
2190         return join_plan;
2191 }
2192
2193 static HashJoin *
2194 create_hashjoin_plan(PlannerInfo *root,
2195                                          HashPath *best_path,
2196                                          Plan *outer_plan,
2197                                          Plan *inner_plan)
2198 {
2199         List       *tlist = build_relation_tlist(best_path->jpath.path.parent);
2200         List       *joinclauses;
2201         List       *otherclauses;
2202         List       *hashclauses;
2203         Oid                     skewTable = InvalidOid;
2204         AttrNumber      skewColumn = InvalidAttrNumber;
2205         bool            skewInherit = false;
2206         Oid                     skewColType = InvalidOid;
2207         int32           skewColTypmod = -1;
2208         HashJoin   *join_plan;
2209         Hash       *hash_plan;
2210
2211         /* Sort join qual clauses into best execution order */
2212         joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
2213         /* There's no point in sorting the hash clauses ... */
2214
2215         /* Get the join qual clauses (in plain expression form) */
2216         /* Any pseudoconstant clauses are ignored here */
2217         if (IS_OUTER_JOIN(best_path->jpath.jointype))
2218         {
2219                 extract_actual_join_clauses(joinclauses,
2220                                                                         &joinclauses, &otherclauses);
2221         }
2222         else
2223         {
2224                 /* We can treat all clauses alike for an inner join */
2225                 joinclauses = extract_actual_clauses(joinclauses, false);
2226                 otherclauses = NIL;
2227         }
2228
2229         /*
2230          * Remove the hashclauses from the list of join qual clauses, leaving the
2231          * list of quals that must be checked as qpquals.
2232          */
2233         hashclauses = get_actual_clauses(best_path->path_hashclauses);
2234         joinclauses = list_difference(joinclauses, hashclauses);
2235
2236         /*
2237          * Rearrange hashclauses, if needed, so that the outer variable is always
2238          * on the left.
2239          */
2240         hashclauses = get_switched_clauses(best_path->path_hashclauses,
2241                                                          best_path->jpath.outerjoinpath->parent->relids);
2242
2243         /* We don't want any excess columns in the hashed tuples */
2244         disuse_physical_tlist(inner_plan, best_path->jpath.innerjoinpath);
2245
2246         /* If we expect batching, suppress excess columns in outer tuples too */
2247         if (best_path->num_batches > 1)
2248                 disuse_physical_tlist(outer_plan, best_path->jpath.outerjoinpath);
2249
2250         /*
2251          * If there is a single join clause and we can identify the outer variable
2252          * as a simple column reference, supply its identity for possible use in
2253          * skew optimization.  (Note: in principle we could do skew optimization
2254          * with multiple join clauses, but we'd have to be able to determine the
2255          * most common combinations of outer values, which we don't currently have
2256          * enough stats for.)
2257          */
2258         if (list_length(hashclauses) == 1)
2259         {
2260                 OpExpr     *clause = (OpExpr *) linitial(hashclauses);
2261                 Node       *node;
2262
2263                 Assert(is_opclause(clause));
2264                 node = (Node *) linitial(clause->args);
2265                 if (IsA(node, RelabelType))
2266                         node = (Node *) ((RelabelType *) node)->arg;
2267                 if (IsA(node, Var))
2268                 {
2269                         Var                *var = (Var *) node;
2270                         RangeTblEntry *rte;
2271
2272                         rte = root->simple_rte_array[var->varno];
2273                         if (rte->rtekind == RTE_RELATION)
2274                         {
2275                                 skewTable = rte->relid;
2276                                 skewColumn = var->varattno;
2277                                 skewInherit = rte->inh;
2278                                 skewColType = var->vartype;
2279                                 skewColTypmod = var->vartypmod;
2280                         }
2281                 }
2282         }
2283
2284         /*
2285          * Build the hash node and hash join node.
2286          */
2287         hash_plan = make_hash(inner_plan,
2288                                                   skewTable,
2289                                                   skewColumn,
2290                                                   skewInherit,
2291                                                   skewColType,
2292                                                   skewColTypmod);
2293         join_plan = make_hashjoin(tlist,
2294                                                           joinclauses,
2295                                                           otherclauses,
2296                                                           hashclauses,
2297                                                           outer_plan,
2298                                                           (Plan *) hash_plan,
2299                                                           best_path->jpath.jointype);
2300
2301         copy_path_costsize(&join_plan->join.plan, &best_path->jpath.path);
2302
2303         return join_plan;
2304 }
2305
2306
2307 /*****************************************************************************
2308  *
2309  *      SUPPORTING ROUTINES
2310  *
2311  *****************************************************************************/
2312
2313 /*
2314  * replace_nestloop_params
2315  *        Replace outer-relation Vars in the given expression with nestloop Params
2316  *
2317  * All Vars belonging to the relation(s) identified by root->curOuterRels
2318  * are replaced by Params, and entries are added to root->curOuterParams if
2319  * not already present.
2320  */
2321 static Node *
2322 replace_nestloop_params(PlannerInfo *root, Node *expr)
2323 {
2324         /* No setup needed for tree walk, so away we go */
2325         return replace_nestloop_params_mutator(expr, root);
2326 }
2327
2328 static Node *
2329 replace_nestloop_params_mutator(Node *node, PlannerInfo *root)
2330 {
2331         if (node == NULL)
2332                 return NULL;
2333         if (IsA(node, Var))
2334         {
2335                 Var                *var = (Var *) node;
2336                 Param      *param;
2337                 NestLoopParam *nlp;
2338                 ListCell   *lc;
2339
2340                 /* Upper-level Vars should be long gone at this point */
2341                 Assert(var->varlevelsup == 0);
2342                 /* If not to be replaced, we can just return the Var unmodified */
2343                 if (!bms_is_member(var->varno, root->curOuterRels))
2344                         return node;
2345                 /* Create a Param representing the Var */
2346                 param = assign_nestloop_param(root, var);
2347                 /* Is this param already listed in root->curOuterParams? */
2348                 foreach(lc, root->curOuterParams)
2349                 {
2350                         nlp = (NestLoopParam *) lfirst(lc);
2351                         if (nlp->paramno == param->paramid)
2352                         {
2353                                 Assert(equal(var, nlp->paramval));
2354                                 /* Present, so we can just return the Param */
2355                                 return (Node *) param;
2356                         }
2357                 }
2358                 /* No, so add it */
2359                 nlp = makeNode(NestLoopParam);
2360                 nlp->paramno = param->paramid;
2361                 nlp->paramval = var;
2362                 root->curOuterParams = lappend(root->curOuterParams, nlp);
2363                 /* And return the replacement Param */
2364                 return (Node *) param;
2365         }
2366         return expression_tree_mutator(node,
2367                                                                    replace_nestloop_params_mutator,
2368                                                                    (void *) root);
2369 }
2370
2371 /*
2372  * fix_indexqual_references
2373  *        Adjust indexqual clauses to the form the executor's indexqual
2374  *        machinery needs.
2375  *
2376  * We have four tasks here:
2377  *      * Remove RestrictInfo nodes from the input clauses.
2378  *      * Replace any outer-relation Var nodes with nestloop Params.
2379  *        (XXX eventually, that responsibility should go elsewhere?)
2380  *      * Index keys must be represented by Var nodes with varattno set to the
2381  *        index's attribute number, not the attribute number in the original rel.
2382  *      * If the index key is on the right, commute the clause to put it on the
2383  *        left.
2384  *
2385  * The result is a modified copy of the indexquals list --- the
2386  * original is not changed.  Note also that the copy shares no substructure
2387  * with the original; this is needed in case there is a subplan in it (we need
2388  * two separate copies of the subplan tree, or things will go awry).
2389  */
2390 static List *
2391 fix_indexqual_references(PlannerInfo *root, IndexPath *index_path,
2392                                                  List *indexquals)
2393 {
2394         IndexOptInfo *index = index_path->indexinfo;
2395         List       *fixed_indexquals;
2396         ListCell   *l;
2397
2398         fixed_indexquals = NIL;
2399
2400         foreach(l, indexquals)
2401         {
2402                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
2403                 Node       *clause;
2404
2405                 Assert(IsA(rinfo, RestrictInfo));
2406
2407                 /*
2408                  * Replace any outer-relation variables with nestloop params.
2409                  *
2410                  * This also makes a copy of the clause, so it's safe to modify it
2411                  * in-place below.
2412                  */
2413                 clause = replace_nestloop_params(root, (Node *) rinfo->clause);
2414
2415                 if (IsA(clause, OpExpr))
2416                 {
2417                         OpExpr     *op = (OpExpr *) clause;
2418
2419                         if (list_length(op->args) != 2)
2420                                 elog(ERROR, "indexqual clause is not binary opclause");
2421
2422                         /*
2423                          * Check to see if the indexkey is on the right; if so, commute
2424                          * the clause. The indexkey should be the side that refers to
2425                          * (only) the base relation.
2426                          */
2427                         if (!bms_equal(rinfo->left_relids, index->rel->relids))
2428                                 CommuteOpExpr(op);
2429
2430                         /*
2431                          * Now, determine which index attribute this is and change the
2432                          * indexkey operand as needed.
2433                          */
2434                         linitial(op->args) = fix_indexqual_operand(linitial(op->args),
2435                                                                                                            index);
2436                 }
2437                 else if (IsA(clause, RowCompareExpr))
2438                 {
2439                         RowCompareExpr *rc = (RowCompareExpr *) clause;
2440                         ListCell   *lc;
2441
2442                         /*
2443                          * Check to see if the indexkey is on the right; if so, commute
2444                          * the clause. The indexkey should be the side that refers to
2445                          * (only) the base relation.
2446                          */
2447                         if (!bms_overlap(pull_varnos(linitial(rc->largs)),
2448                                                          index->rel->relids))
2449                                 CommuteRowCompareExpr(rc);
2450
2451                         /*
2452                          * For each column in the row comparison, determine which index
2453                          * attribute this is and change the indexkey operand as needed.
2454                          */
2455                         foreach(lc, rc->largs)
2456                         {
2457                                 lfirst(lc) = fix_indexqual_operand(lfirst(lc),
2458                                                                                                    index);
2459                         }
2460                 }
2461                 else if (IsA(clause, ScalarArrayOpExpr))
2462                 {
2463                         ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
2464
2465                         /* Never need to commute... */
2466
2467                         /*
2468                          * Determine which index attribute this is and change the indexkey
2469                          * operand as needed.
2470                          */
2471                         linitial(saop->args) = fix_indexqual_operand(linitial(saop->args),
2472                                                                                                                  index);
2473                 }
2474                 else if (IsA(clause, NullTest))
2475                 {
2476                         NullTest   *nt = (NullTest *) clause;
2477
2478                         nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg,
2479                                                                                                          index);
2480                 }
2481                 else
2482                         elog(ERROR, "unsupported indexqual type: %d",
2483                                  (int) nodeTag(clause));
2484
2485                 fixed_indexquals = lappend(fixed_indexquals, clause);
2486         }
2487
2488         return fixed_indexquals;
2489 }
2490
2491 /*
2492  * fix_indexorderby_references
2493  *        Adjust indexorderby clauses to the form the executor's index
2494  *        machinery needs.
2495  *
2496  * This is a simplified version of fix_indexqual_references.  The input does
2497  * not have RestrictInfo nodes, and we assume that indxqual.c already
2498  * commuted the clauses to put the index keys on the left.      Also, we don't
2499  * bother to support any cases except simple OpExprs, since nothing else
2500  * is allowed for ordering operators.
2501  */
2502 static List *
2503 fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path,
2504                                                         List *indexorderbys)
2505 {
2506         IndexOptInfo *index = index_path->indexinfo;
2507         List       *fixed_indexorderbys;
2508         ListCell   *l;
2509
2510         fixed_indexorderbys = NIL;
2511
2512         foreach(l, indexorderbys)
2513         {
2514                 Node       *clause = (Node *) lfirst(l);
2515
2516                 /*
2517                  * Replace any outer-relation variables with nestloop params.
2518                  *
2519                  * This also makes a copy of the clause, so it's safe to modify it
2520                  * in-place below.
2521                  */
2522                 clause = replace_nestloop_params(root, clause);
2523
2524                 if (IsA(clause, OpExpr))
2525                 {
2526                         OpExpr     *op = (OpExpr *) clause;
2527
2528                         if (list_length(op->args) != 2)
2529                                 elog(ERROR, "indexorderby clause is not binary opclause");
2530
2531                         /*
2532                          * Now, determine which index attribute this is and change the
2533                          * indexkey operand as needed.
2534                          */
2535                         linitial(op->args) = fix_indexqual_operand(linitial(op->args),
2536                                                                                                            index);
2537                 }
2538                 else
2539                         elog(ERROR, "unsupported indexorderby type: %d",
2540                                  (int) nodeTag(clause));
2541
2542                 fixed_indexorderbys = lappend(fixed_indexorderbys, clause);
2543         }
2544
2545         return fixed_indexorderbys;
2546 }
2547
2548 /*
2549  * fix_indexqual_operand
2550  *        Convert an indexqual expression to a Var referencing the index column.
2551  */
2552 static Node *
2553 fix_indexqual_operand(Node *node, IndexOptInfo *index)
2554 {
2555         /*
2556          * We represent index keys by Var nodes having the varno of the base table
2557          * but varattno equal to the index's attribute number (index column
2558          * position).  This is a bit hokey ... would be cleaner to use a
2559          * special-purpose node type that could not be mistaken for a regular Var.
2560          * But it will do for now.
2561          */
2562         Var                *result;
2563         int                     pos;
2564         ListCell   *indexpr_item;
2565
2566         /*
2567          * Remove any binary-compatible relabeling of the indexkey
2568          */
2569         if (IsA(node, RelabelType))
2570                 node = (Node *) ((RelabelType *) node)->arg;
2571
2572         if (IsA(node, Var) &&
2573                 ((Var *) node)->varno == index->rel->relid)
2574         {
2575                 /* Try to match against simple index columns */
2576                 int                     varatt = ((Var *) node)->varattno;
2577
2578                 if (varatt != 0)
2579                 {
2580                         for (pos = 0; pos < index->ncolumns; pos++)
2581                         {
2582                                 if (index->indexkeys[pos] == varatt)
2583                                 {
2584                                         result = (Var *) copyObject(node);
2585                                         result->varattno = pos + 1;
2586                                         return (Node *) result;
2587                                 }
2588                         }
2589                 }
2590         }
2591
2592         /* Try to match against index expressions */
2593         indexpr_item = list_head(index->indexprs);
2594         for (pos = 0; pos < index->ncolumns; pos++)
2595         {
2596                 if (index->indexkeys[pos] == 0)
2597                 {
2598                         Node       *indexkey;
2599
2600                         if (indexpr_item == NULL)
2601                                 elog(ERROR, "too few entries in indexprs list");
2602                         indexkey = (Node *) lfirst(indexpr_item);
2603                         if (indexkey && IsA(indexkey, RelabelType))
2604                                 indexkey = (Node *) ((RelabelType *) indexkey)->arg;
2605                         if (equal(node, indexkey))
2606                         {
2607                                 /* Found a match */
2608                                 result = makeVar(index->rel->relid, pos + 1,
2609                                                                  exprType(lfirst(indexpr_item)), -1,
2610                                                                  exprCollation(lfirst(indexpr_item)),
2611                                                                  0);
2612                                 return (Node *) result;
2613                         }
2614                         indexpr_item = lnext(indexpr_item);
2615                 }
2616         }
2617
2618         /* Ooops... */
2619         elog(ERROR, "node is not an index attribute");
2620         return NULL;                            /* keep compiler quiet */
2621 }
2622
2623 /*
2624  * get_switched_clauses
2625  *        Given a list of merge or hash joinclauses (as RestrictInfo nodes),
2626  *        extract the bare clauses, and rearrange the elements within the
2627  *        clauses, if needed, so the outer join variable is on the left and
2628  *        the inner is on the right.  The original clause data structure is not
2629  *        touched; a modified list is returned.  We do, however, set the transient
2630  *        outer_is_left field in each RestrictInfo to show which side was which.
2631  */
2632 static List *
2633 get_switched_clauses(List *clauses, Relids outerrelids)
2634 {
2635         List       *t_list = NIL;
2636         ListCell   *l;
2637
2638         foreach(l, clauses)
2639         {
2640                 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(l);
2641                 OpExpr     *clause = (OpExpr *) restrictinfo->clause;
2642
2643                 Assert(is_opclause(clause));
2644                 if (bms_is_subset(restrictinfo->right_relids, outerrelids))
2645                 {
2646                         /*
2647                          * Duplicate just enough of the structure to allow commuting the
2648                          * clause without changing the original list.  Could use
2649                          * copyObject, but a complete deep copy is overkill.
2650                          */
2651                         OpExpr     *temp = makeNode(OpExpr);
2652
2653                         temp->opno = clause->opno;
2654                         temp->opfuncid = InvalidOid;
2655                         temp->opresulttype = clause->opresulttype;
2656                         temp->opretset = clause->opretset;
2657                         temp->opcollid = clause->opcollid;
2658                         temp->inputcollid = clause->inputcollid;
2659                         temp->args = list_copy(clause->args);
2660                         temp->location = clause->location;
2661                         /* Commute it --- note this modifies the temp node in-place. */
2662                         CommuteOpExpr(temp);
2663                         t_list = lappend(t_list, temp);
2664                         restrictinfo->outer_is_left = false;
2665                 }
2666                 else
2667                 {
2668                         Assert(bms_is_subset(restrictinfo->left_relids, outerrelids));
2669                         t_list = lappend(t_list, clause);
2670                         restrictinfo->outer_is_left = true;
2671                 }
2672         }
2673         return t_list;
2674 }
2675
2676 /*
2677  * order_qual_clauses
2678  *              Given a list of qual clauses that will all be evaluated at the same
2679  *              plan node, sort the list into the order we want to check the quals
2680  *              in at runtime.
2681  *
2682  * Ideally the order should be driven by a combination of execution cost and
2683  * selectivity, but it's not immediately clear how to account for both,
2684  * and given the uncertainty of the estimates the reliability of the decisions
2685  * would be doubtful anyway.  So we just order by estimated per-tuple cost,
2686  * being careful not to change the order when (as is often the case) the
2687  * estimates are identical.
2688  *
2689  * Although this will work on either bare clauses or RestrictInfos, it's
2690  * much faster to apply it to RestrictInfos, since it can re-use cost
2691  * information that is cached in RestrictInfos.
2692  *
2693  * Note: some callers pass lists that contain entries that will later be
2694  * removed; this is the easiest way to let this routine see RestrictInfos
2695  * instead of bare clauses.  It's OK because we only sort by cost, but
2696  * a cost/selectivity combination would likely do the wrong thing.
2697  */
2698 static List *
2699 order_qual_clauses(PlannerInfo *root, List *clauses)
2700 {
2701         typedef struct
2702         {
2703                 Node       *clause;
2704                 Cost            cost;
2705         } QualItem;
2706         int                     nitems = list_length(clauses);
2707         QualItem   *items;
2708         ListCell   *lc;
2709         int                     i;
2710         List       *result;
2711
2712         /* No need to work hard for 0 or 1 clause */
2713         if (nitems <= 1)
2714                 return clauses;
2715
2716         /*
2717          * Collect the items and costs into an array.  This is to avoid repeated
2718          * cost_qual_eval work if the inputs aren't RestrictInfos.
2719          */
2720         items = (QualItem *) palloc(nitems * sizeof(QualItem));
2721         i = 0;
2722         foreach(lc, clauses)
2723         {
2724                 Node       *clause = (Node *) lfirst(lc);
2725                 QualCost        qcost;
2726
2727                 cost_qual_eval_node(&qcost, clause, root);
2728                 items[i].clause = clause;
2729                 items[i].cost = qcost.per_tuple;
2730                 i++;
2731         }
2732
2733         /*
2734          * Sort.  We don't use qsort() because it's not guaranteed stable for
2735          * equal keys.  The expected number of entries is small enough that a
2736          * simple insertion sort should be good enough.
2737          */
2738         for (i = 1; i < nitems; i++)
2739         {
2740                 QualItem        newitem = items[i];
2741                 int                     j;
2742
2743                 /* insert newitem into the already-sorted subarray */
2744                 for (j = i; j > 0; j--)
2745                 {
2746                         if (newitem.cost >= items[j - 1].cost)
2747                                 break;
2748                         items[j] = items[j - 1];
2749                 }
2750                 items[j] = newitem;
2751         }
2752
2753         /* Convert back to a list */
2754         result = NIL;
2755         for (i = 0; i < nitems; i++)
2756                 result = lappend(result, items[i].clause);
2757
2758         return result;
2759 }
2760
2761 /*
2762  * Copy cost and size info from a Path node to the Plan node created from it.
2763  * The executor usually won't use this info, but it's needed by EXPLAIN.
2764  */
2765 static void
2766 copy_path_costsize(Plan *dest, Path *src)
2767 {
2768         if (src)
2769         {
2770                 dest->startup_cost = src->startup_cost;
2771                 dest->total_cost = src->total_cost;
2772                 dest->plan_rows = src->parent->rows;
2773                 dest->plan_width = src->parent->width;
2774         }
2775         else
2776         {
2777                 dest->startup_cost = 0;
2778                 dest->total_cost = 0;
2779                 dest->plan_rows = 0;
2780                 dest->plan_width = 0;
2781         }
2782 }
2783
2784 /*
2785  * Copy cost and size info from a lower plan node to an inserted node.
2786  * (Most callers alter the info after copying it.)
2787  */
2788 static void
2789 copy_plan_costsize(Plan *dest, Plan *src)
2790 {
2791         if (src)
2792         {
2793                 dest->startup_cost = src->startup_cost;
2794                 dest->total_cost = src->total_cost;
2795                 dest->plan_rows = src->plan_rows;
2796                 dest->plan_width = src->plan_width;
2797         }
2798         else
2799         {
2800                 dest->startup_cost = 0;
2801                 dest->total_cost = 0;
2802                 dest->plan_rows = 0;
2803                 dest->plan_width = 0;
2804         }
2805 }
2806
2807
2808 /*****************************************************************************
2809  *
2810  *      PLAN NODE BUILDING ROUTINES
2811  *
2812  * Some of these are exported because they are called to build plan nodes
2813  * in contexts where we're not deriving the plan node from a path node.
2814  *
2815  *****************************************************************************/
2816
2817 static SeqScan *
2818 make_seqscan(List *qptlist,
2819                          List *qpqual,
2820                          Index scanrelid)
2821 {
2822         SeqScan    *node = makeNode(SeqScan);
2823         Plan       *plan = &node->plan;
2824
2825         /* cost should be inserted by caller */
2826         plan->targetlist = qptlist;
2827         plan->qual = qpqual;
2828         plan->lefttree = NULL;
2829         plan->righttree = NULL;
2830         node->scanrelid = scanrelid;
2831
2832         return node;
2833 }
2834
2835 static IndexScan *
2836 make_indexscan(List *qptlist,
2837                            List *qpqual,
2838                            Index scanrelid,
2839                            Oid indexid,
2840                            List *indexqual,
2841                            List *indexqualorig,
2842                            List *indexorderby,
2843                            List *indexorderbyorig,
2844                            ScanDirection indexscandir)
2845 {
2846         IndexScan  *node = makeNode(IndexScan);
2847         Plan       *plan = &node->scan.plan;
2848
2849         /* cost should be inserted by caller */
2850         plan->targetlist = qptlist;
2851         plan->qual = qpqual;
2852         plan->lefttree = NULL;
2853         plan->righttree = NULL;
2854         node->scan.scanrelid = scanrelid;
2855         node->indexid = indexid;
2856         node->indexqual = indexqual;
2857         node->indexqualorig = indexqualorig;
2858         node->indexorderby = indexorderby;
2859         node->indexorderbyorig = indexorderbyorig;
2860         node->indexorderdir = indexscandir;
2861
2862         return node;
2863 }
2864
2865 static BitmapIndexScan *
2866 make_bitmap_indexscan(Index scanrelid,
2867                                           Oid indexid,
2868                                           List *indexqual,
2869                                           List *indexqualorig)
2870 {
2871         BitmapIndexScan *node = makeNode(BitmapIndexScan);
2872         Plan       *plan = &node->scan.plan;
2873
2874         /* cost should be inserted by caller */
2875         plan->targetlist = NIL;         /* not used */
2876         plan->qual = NIL;                       /* not used */
2877         plan->lefttree = NULL;
2878         plan->righttree = NULL;
2879         node->scan.scanrelid = scanrelid;
2880         node->indexid = indexid;
2881         node->indexqual = indexqual;
2882         node->indexqualorig = indexqualorig;
2883
2884         return node;
2885 }
2886
2887 static BitmapHeapScan *
2888 make_bitmap_heapscan(List *qptlist,
2889                                          List *qpqual,
2890                                          Plan *lefttree,
2891                                          List *bitmapqualorig,
2892                                          Index scanrelid)
2893 {
2894         BitmapHeapScan *node = makeNode(BitmapHeapScan);
2895         Plan       *plan = &node->scan.plan;
2896
2897         /* cost should be inserted by caller */
2898         plan->targetlist = qptlist;
2899         plan->qual = qpqual;
2900         plan->lefttree = lefttree;
2901         plan->righttree = NULL;
2902         node->scan.scanrelid = scanrelid;
2903         node->bitmapqualorig = bitmapqualorig;
2904
2905         return node;
2906 }
2907
2908 static TidScan *
2909 make_tidscan(List *qptlist,
2910                          List *qpqual,
2911                          Index scanrelid,
2912                          List *tidquals)
2913 {
2914         TidScan    *node = makeNode(TidScan);
2915         Plan       *plan = &node->scan.plan;
2916
2917         /* cost should be inserted by caller */
2918         plan->targetlist = qptlist;
2919         plan->qual = qpqual;
2920         plan->lefttree = NULL;
2921         plan->righttree = NULL;
2922         node->scan.scanrelid = scanrelid;
2923         node->tidquals = tidquals;
2924
2925         return node;
2926 }
2927
2928 SubqueryScan *
2929 make_subqueryscan(List *qptlist,
2930                                   List *qpqual,
2931                                   Index scanrelid,
2932                                   Plan *subplan)
2933 {
2934         SubqueryScan *node = makeNode(SubqueryScan);
2935         Plan       *plan = &node->scan.plan;
2936
2937         /*
2938          * Cost is figured here for the convenience of prepunion.c.  Note this is
2939          * only correct for the case where qpqual is empty; otherwise caller
2940          * should overwrite cost with a better estimate.
2941          */
2942         copy_plan_costsize(plan, subplan);
2943         plan->total_cost += cpu_tuple_cost * subplan->plan_rows;
2944
2945         plan->targetlist = qptlist;
2946         plan->qual = qpqual;
2947         plan->lefttree = NULL;
2948         plan->righttree = NULL;
2949         node->scan.scanrelid = scanrelid;
2950         node->subplan = subplan;
2951
2952         return node;
2953 }
2954
2955 static FunctionScan *
2956 make_functionscan(List *qptlist,
2957                                   List *qpqual,
2958                                   Index scanrelid,
2959                                   Node *funcexpr,
2960                                   List *funccolnames,
2961                                   List *funccoltypes,
2962                                   List *funccoltypmods,
2963                                   List *funccolcollations)
2964 {
2965         FunctionScan *node = makeNode(FunctionScan);
2966         Plan       *plan = &node->scan.plan;
2967
2968         /* cost should be inserted by caller */
2969         plan->targetlist = qptlist;
2970         plan->qual = qpqual;
2971         plan->lefttree = NULL;
2972         plan->righttree = NULL;
2973         node->scan.scanrelid = scanrelid;
2974         node->funcexpr = funcexpr;
2975         node->funccolnames = funccolnames;
2976         node->funccoltypes = funccoltypes;
2977         node->funccoltypmods = funccoltypmods;
2978         node->funccolcollations = funccolcollations;
2979
2980         return node;
2981 }
2982
2983 static ValuesScan *
2984 make_valuesscan(List *qptlist,
2985                                 List *qpqual,
2986                                 Index scanrelid,
2987                                 List *values_lists)
2988 {
2989         ValuesScan *node = makeNode(ValuesScan);
2990         Plan       *plan = &node->scan.plan;
2991
2992         /* cost should be inserted by caller */
2993         plan->targetlist = qptlist;
2994         plan->qual = qpqual;
2995         plan->lefttree = NULL;
2996         plan->righttree = NULL;
2997         node->scan.scanrelid = scanrelid;
2998         node->values_lists = values_lists;
2999
3000         return node;
3001 }
3002
3003 static CteScan *
3004 make_ctescan(List *qptlist,
3005                          List *qpqual,
3006                          Index scanrelid,
3007                          int ctePlanId,
3008                          int cteParam)
3009 {
3010         CteScan    *node = makeNode(CteScan);
3011         Plan       *plan = &node->scan.plan;
3012
3013         /* cost should be inserted by caller */
3014         plan->targetlist = qptlist;
3015         plan->qual = qpqual;
3016         plan->lefttree = NULL;
3017         plan->righttree = NULL;
3018         node->scan.scanrelid = scanrelid;
3019         node->ctePlanId = ctePlanId;
3020         node->cteParam = cteParam;
3021
3022         return node;
3023 }
3024
3025 static WorkTableScan *
3026 make_worktablescan(List *qptlist,
3027                                    List *qpqual,
3028                                    Index scanrelid,
3029                                    int wtParam)
3030 {
3031         WorkTableScan *node = makeNode(WorkTableScan);
3032         Plan       *plan = &node->scan.plan;
3033
3034         /* cost should be inserted by caller */
3035         plan->targetlist = qptlist;
3036         plan->qual = qpqual;
3037         plan->lefttree = NULL;
3038         plan->righttree = NULL;
3039         node->scan.scanrelid = scanrelid;
3040         node->wtParam = wtParam;
3041
3042         return node;
3043 }
3044
3045 static ForeignScan *
3046 make_foreignscan(List *qptlist,
3047                                  List *qpqual,
3048                                  Index scanrelid,
3049                                  bool fsSystemCol,
3050                                  FdwPlan *fdwplan)
3051 {
3052         ForeignScan *node = makeNode(ForeignScan);
3053         Plan       *plan = &node->scan.plan;
3054
3055         /* cost should be inserted by caller */
3056         plan->targetlist = qptlist;
3057         plan->qual = qpqual;
3058         plan->lefttree = NULL;
3059         plan->righttree = NULL;
3060         node->scan.scanrelid = scanrelid;
3061         node->fsSystemCol = fsSystemCol;
3062         node->fdwplan = fdwplan;
3063
3064         return node;
3065 }
3066
3067 Append *
3068 make_append(List *appendplans, List *tlist)
3069 {
3070         Append     *node = makeNode(Append);
3071         Plan       *plan = &node->plan;
3072         double          total_size;
3073         ListCell   *subnode;
3074
3075         /*
3076          * Compute cost as sum of subplan costs.  We charge nothing extra for the
3077          * Append itself, which perhaps is too optimistic, but since it doesn't do
3078          * any selection or projection, it is a pretty cheap node.
3079          *
3080          * If you change this, see also create_append_path().  Also, the size
3081          * calculations should match set_append_rel_pathlist().  It'd be better
3082          * not to duplicate all this logic, but some callers of this function
3083          * aren't working from an appendrel or AppendPath, so there's noplace to
3084          * copy the data from.
3085          */
3086         plan->startup_cost = 0;
3087         plan->total_cost = 0;
3088         plan->plan_rows = 0;
3089         total_size = 0;
3090         foreach(subnode, appendplans)
3091         {
3092                 Plan       *subplan = (Plan *) lfirst(subnode);
3093
3094                 if (subnode == list_head(appendplans))  /* first node? */
3095                         plan->startup_cost = subplan->startup_cost;
3096                 plan->total_cost += subplan->total_cost;
3097                 plan->plan_rows += subplan->plan_rows;
3098                 total_size += subplan->plan_width * subplan->plan_rows;
3099         }
3100         if (plan->plan_rows > 0)
3101                 plan->plan_width = rint(total_size / plan->plan_rows);
3102         else
3103                 plan->plan_width = 0;
3104
3105         plan->targetlist = tlist;
3106         plan->qual = NIL;
3107         plan->lefttree = NULL;
3108         plan->righttree = NULL;
3109         node->appendplans = appendplans;
3110
3111         return node;
3112 }
3113
3114 RecursiveUnion *
3115 make_recursive_union(List *tlist,
3116                                          Plan *lefttree,
3117                                          Plan *righttree,
3118                                          int wtParam,
3119                                          List *distinctList,
3120                                          long numGroups)
3121 {
3122         RecursiveUnion *node = makeNode(RecursiveUnion);
3123         Plan       *plan = &node->plan;
3124         int                     numCols = list_length(distinctList);
3125
3126         cost_recursive_union(plan, lefttree, righttree);
3127
3128         plan->targetlist = tlist;
3129         plan->qual = NIL;
3130         plan->lefttree = lefttree;
3131         plan->righttree = righttree;
3132         node->wtParam = wtParam;
3133
3134         /*
3135          * convert SortGroupClause list into arrays of attr indexes and equality
3136          * operators, as wanted by executor
3137          */
3138         node->numCols = numCols;
3139         if (numCols > 0)
3140         {
3141                 int                     keyno = 0;
3142                 AttrNumber *dupColIdx;
3143                 Oid                *dupOperators;
3144                 ListCell   *slitem;
3145
3146                 dupColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
3147                 dupOperators = (Oid *) palloc(sizeof(Oid) * numCols);
3148
3149                 foreach(slitem, distinctList)
3150                 {
3151                         SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
3152                         TargetEntry *tle = get_sortgroupclause_tle(sortcl,
3153                                                                                                            plan->targetlist);
3154
3155                         dupColIdx[keyno] = tle->resno;
3156                         dupOperators[keyno] = sortcl->eqop;
3157                         Assert(OidIsValid(dupOperators[keyno]));
3158                         keyno++;
3159                 }
3160                 node->dupColIdx = dupColIdx;
3161                 node->dupOperators = dupOperators;
3162         }
3163         node->numGroups = numGroups;
3164
3165         return node;
3166 }
3167
3168 static BitmapAnd *
3169 make_bitmap_and(List *bitmapplans)
3170 {
3171         BitmapAnd  *node = makeNode(BitmapAnd);
3172         Plan       *plan = &node->plan;
3173
3174         /* cost should be inserted by caller */
3175         plan->targetlist = NIL;
3176         plan->qual = NIL;
3177         plan->lefttree = NULL;
3178         plan->righttree = NULL;
3179         node->bitmapplans = bitmapplans;
3180
3181         return node;
3182 }
3183
3184 static BitmapOr *
3185 make_bitmap_or(List *bitmapplans)
3186 {
3187         BitmapOr   *node = makeNode(BitmapOr);
3188         Plan       *plan = &node->plan;
3189
3190         /* cost should be inserted by caller */
3191         plan->targetlist = NIL;
3192         plan->qual = NIL;
3193         plan->lefttree = NULL;
3194         plan->righttree = NULL;
3195         node->bitmapplans = bitmapplans;
3196
3197         return node;
3198 }
3199
3200 static NestLoop *
3201 make_nestloop(List *tlist,
3202                           List *joinclauses,
3203                           List *otherclauses,
3204                           List *nestParams,
3205                           Plan *lefttree,
3206                           Plan *righttree,
3207                           JoinType jointype)
3208 {
3209         NestLoop   *node = makeNode(NestLoop);
3210         Plan       *plan = &node->join.plan;
3211
3212         /* cost should be inserted by caller */
3213         plan->targetlist = tlist;
3214         plan->qual = otherclauses;
3215         plan->lefttree = lefttree;
3216         plan->righttree = righttree;
3217         node->join.jointype = jointype;
3218         node->join.joinqual = joinclauses;
3219         node->nestParams = nestParams;
3220
3221         return node;
3222 }
3223
3224 static HashJoin *
3225 make_hashjoin(List *tlist,
3226                           List *joinclauses,
3227                           List *otherclauses,
3228                           List *hashclauses,
3229                           Plan *lefttree,
3230                           Plan *righttree,
3231                           JoinType jointype)
3232 {
3233         HashJoin   *node = makeNode(HashJoin);
3234         Plan       *plan = &node->join.plan;
3235
3236         /* cost should be inserted by caller */
3237         plan->targetlist = tlist;
3238         plan->qual = otherclauses;
3239         plan->lefttree = lefttree;
3240         plan->righttree = righttree;
3241         node->hashclauses = hashclauses;
3242         node->join.jointype = jointype;
3243         node->join.joinqual = joinclauses;
3244
3245         return node;
3246 }
3247
3248 static Hash *
3249 make_hash(Plan *lefttree,
3250                   Oid skewTable,
3251                   AttrNumber skewColumn,
3252                   bool skewInherit,
3253                   Oid skewColType,
3254                   int32 skewColTypmod)
3255 {
3256         Hash       *node = makeNode(Hash);
3257         Plan       *plan = &node->plan;
3258
3259         copy_plan_costsize(plan, lefttree);
3260
3261         /*
3262          * For plausibility, make startup & total costs equal total cost of input
3263          * plan; this only affects EXPLAIN display not decisions.
3264          */
3265         plan->startup_cost = plan->total_cost;
3266         plan->targetlist = lefttree->targetlist;
3267         plan->qual = NIL;
3268         plan->lefttree = lefttree;
3269         plan->righttree = NULL;
3270
3271         node->skewTable = skewTable;
3272         node->skewColumn = skewColumn;
3273         node->skewInherit = skewInherit;
3274         node->skewColType = skewColType;
3275         node->skewColTypmod = skewColTypmod;
3276
3277         return node;
3278 }
3279
3280 static MergeJoin *
3281 make_mergejoin(List *tlist,
3282                            List *joinclauses,
3283                            List *otherclauses,
3284                            List *mergeclauses,
3285                            Oid *mergefamilies,
3286                            Oid *mergecollations,
3287                            int *mergestrategies,
3288                            bool *mergenullsfirst,
3289                            Plan *lefttree,
3290                            Plan *righttree,
3291                            JoinType jointype)
3292 {
3293         MergeJoin  *node = makeNode(MergeJoin);
3294         Plan       *plan = &node->join.plan;
3295
3296         /* cost should be inserted by caller */
3297         plan->targetlist = tlist;
3298         plan->qual = otherclauses;
3299         plan->lefttree = lefttree;
3300         plan->righttree = righttree;
3301         node->mergeclauses = mergeclauses;
3302         node->mergeFamilies = mergefamilies;
3303         node->mergeCollations = mergecollations;
3304         node->mergeStrategies = mergestrategies;
3305         node->mergeNullsFirst = mergenullsfirst;
3306         node->join.jointype = jointype;
3307         node->join.joinqual = joinclauses;
3308
3309         return node;
3310 }
3311
3312 /*
3313  * make_sort --- basic routine to build a Sort plan node
3314  *
3315  * Caller must have built the sortColIdx, sortOperators, collations, and
3316  * nullsFirst arrays already.
3317  * limit_tuples is as for cost_sort (in particular, pass -1 if no limit)
3318  */
3319 static Sort *
3320 make_sort(PlannerInfo *root, Plan *lefttree, int numCols,
3321                   AttrNumber *sortColIdx, Oid *sortOperators,
3322                   Oid *collations, bool *nullsFirst,
3323                   double limit_tuples)
3324 {
3325         Sort       *node = makeNode(Sort);
3326         Plan       *plan = &node->plan;
3327         Path            sort_path;              /* dummy for result of cost_sort */
3328
3329         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3330         cost_sort(&sort_path, root, NIL,
3331                           lefttree->total_cost,
3332                           lefttree->plan_rows,
3333                           lefttree->plan_width,
3334                           0.0,
3335                           work_mem,
3336                           limit_tuples);
3337         plan->startup_cost = sort_path.startup_cost;
3338         plan->total_cost = sort_path.total_cost;
3339         plan->targetlist = lefttree->targetlist;
3340         plan->qual = NIL;
3341         plan->lefttree = lefttree;
3342         plan->righttree = NULL;
3343         node->numCols = numCols;
3344         node->sortColIdx = sortColIdx;
3345         node->sortOperators = sortOperators;
3346         node->collations = collations;
3347         node->nullsFirst = nullsFirst;
3348
3349         return node;
3350 }
3351
3352 /*
3353  * add_sort_column --- utility subroutine for building sort info arrays
3354  *
3355  * We need this routine because the same column might be selected more than
3356  * once as a sort key column; if so, the extra mentions are redundant.
3357  *
3358  * Caller is assumed to have allocated the arrays large enough for the
3359  * max possible number of columns.      Return value is the new column count.
3360  */
3361 static int
3362 add_sort_column(AttrNumber colIdx, Oid sortOp, Oid coll, bool nulls_first,
3363                                 int numCols, AttrNumber *sortColIdx,
3364                                 Oid *sortOperators, Oid *collations, bool *nullsFirst)
3365 {
3366         int                     i;
3367
3368         Assert(OidIsValid(sortOp));
3369
3370         for (i = 0; i < numCols; i++)
3371         {
3372                 /*
3373                  * Note: we check sortOp because it's conceivable that "ORDER BY foo
3374                  * USING <, foo USING <<<" is not redundant, if <<< distinguishes
3375                  * values that < considers equal.  We need not check nulls_first
3376                  * however because a lower-order column with the same sortop but
3377                  * opposite nulls direction is redundant.
3378                  *
3379                  * We could probably consider sort keys with the same sortop and
3380                  * different collations to be redundant too, but for the moment treat
3381                  * them as not redundant.  This will be needed if we ever support
3382                  * collations with different notions of equality.
3383                  */
3384                 if (sortColIdx[i] == colIdx &&
3385                         sortOperators[numCols] == sortOp &&
3386                         collations[numCols] == coll)
3387                 {
3388                         /* Already sorting by this col, so extra sort key is useless */
3389                         return numCols;
3390                 }
3391         }
3392
3393         /* Add the column */
3394         sortColIdx[numCols] = colIdx;
3395         sortOperators[numCols] = sortOp;
3396         collations[numCols] = coll;
3397         nullsFirst[numCols] = nulls_first;
3398         return numCols + 1;
3399 }
3400
3401 /*
3402  * prepare_sort_from_pathkeys
3403  *        Prepare to sort according to given pathkeys
3404  *
3405  * This is used to set up for both Sort and MergeAppend nodes.  It calculates
3406  * the executor's representation of the sort key information, and adjusts the
3407  * plan targetlist if needed to add resjunk sort columns.
3408  *
3409  * Input parameters:
3410  *        'lefttree' is the node which yields input tuples
3411  *        'pathkeys' is the list of pathkeys by which the result is to be sorted
3412  *        'adjust_tlist_in_place' is TRUE if lefttree must be modified in-place
3413  *
3414  * We must convert the pathkey information into arrays of sort key column
3415  * numbers, sort operator OIDs, collation OIDs, and nulls-first flags,
3416  * which is the representation the executor wants.      These are returned into
3417  * the output parameters *p_numsortkeys etc.
3418  *
3419  * If the pathkeys include expressions that aren't simple Vars, we will
3420  * usually need to add resjunk items to the input plan's targetlist to
3421  * compute these expressions, since the Sort/MergeAppend node itself won't
3422  * do any such calculations.  If the input plan type isn't one that can do
3423  * projections, this means adding a Result node just to do the projection.
3424  * However, the caller can pass adjust_tlist_in_place = TRUE to force the
3425  * lefttree tlist to be modified in-place regardless of whether the node type
3426  * can project --- we use this for fixing the tlist of MergeAppend itself.
3427  *
3428  * Returns the node which is to be the input to the Sort (either lefttree,
3429  * or a Result stacked atop lefttree).
3430  */
3431 static Plan *
3432 prepare_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree, List *pathkeys,
3433                                                    bool adjust_tlist_in_place,
3434                                                    int *p_numsortkeys,
3435                                                    AttrNumber **p_sortColIdx,
3436                                                    Oid **p_sortOperators,
3437                                                    Oid **p_collations,
3438                                                    bool **p_nullsFirst)
3439 {
3440         List       *tlist = lefttree->targetlist;
3441         ListCell   *i;
3442         int                     numsortkeys;
3443         AttrNumber *sortColIdx;
3444         Oid                *sortOperators;
3445         Oid                *collations;
3446         bool       *nullsFirst;
3447
3448         /*
3449          * We will need at most list_length(pathkeys) sort columns; possibly less
3450          */
3451         numsortkeys = list_length(pathkeys);
3452         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
3453         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
3454         collations = (Oid *) palloc(numsortkeys * sizeof(Oid));
3455         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
3456
3457         numsortkeys = 0;
3458
3459         foreach(i, pathkeys)
3460         {
3461                 PathKey    *pathkey = (PathKey *) lfirst(i);
3462                 EquivalenceClass *ec = pathkey->pk_eclass;
3463                 TargetEntry *tle = NULL;
3464                 Oid                     pk_datatype = InvalidOid;
3465                 Oid                     sortop;
3466                 ListCell   *j;
3467
3468                 if (ec->ec_has_volatile)
3469                 {
3470                         /*
3471                          * If the pathkey's EquivalenceClass is volatile, then it must
3472                          * have come from an ORDER BY clause, and we have to match it to
3473                          * that same targetlist entry.
3474                          */
3475                         if (ec->ec_sortref == 0)        /* can't happen */
3476                                 elog(ERROR, "volatile EquivalenceClass has no sortref");
3477                         tle = get_sortgroupref_tle(ec->ec_sortref, tlist);
3478                         Assert(tle);
3479                         Assert(list_length(ec->ec_members) == 1);
3480                         pk_datatype = ((EquivalenceMember *) linitial(ec->ec_members))->em_datatype;
3481                 }
3482                 else
3483                 {
3484                         /*
3485                          * Otherwise, we can sort by any non-constant expression listed in
3486                          * the pathkey's EquivalenceClass.  For now, we take the first one
3487                          * that corresponds to an available item in the tlist.  If there
3488                          * isn't any, use the first one that is an expression in the
3489                          * input's vars.  (The non-const restriction only matters if the
3490                          * EC is below_outer_join; but if it isn't, it won't contain
3491                          * consts anyway, else we'd have discarded the pathkey as
3492                          * redundant.)
3493                          *
3494                          * XXX if we have a choice, is there any way of figuring out which
3495                          * might be cheapest to execute?  (For example, int4lt is likely
3496                          * much cheaper to execute than numericlt, but both might appear
3497                          * in the same equivalence class...)  Not clear that we ever will
3498                          * have an interesting choice in practice, so it may not matter.
3499                          */
3500                         foreach(j, ec->ec_members)
3501                         {
3502                                 EquivalenceMember *em = (EquivalenceMember *) lfirst(j);
3503
3504                                 /*
3505                                  * We shouldn't be trying to sort by an equivalence class that
3506                                  * contains a constant, so no need to consider such cases any
3507                                  * further.
3508                                  */
3509                                 if (em->em_is_const)
3510                                         continue;
3511
3512                                 tle = tlist_member((Node *) em->em_expr, tlist);
3513                                 if (tle)
3514                                 {
3515                                         pk_datatype = em->em_datatype;
3516                                         break;          /* found expr already in tlist */
3517                                 }
3518
3519                                 /*
3520                                  * We can also use it if the pathkey expression is a relabel
3521                                  * of the tlist entry, or vice versa.  This is needed for
3522                                  * binary-compatible cases (cf. make_pathkey_from_sortinfo).
3523                                  * We prefer an exact match, though, so we do the basic search
3524                                  * first.
3525                                  */
3526                                 tle = tlist_member_ignore_relabel((Node *) em->em_expr, tlist);
3527                                 if (tle)
3528                                 {
3529                                         pk_datatype = em->em_datatype;
3530                                         break;          /* found expr already in tlist */
3531                                 }
3532                         }
3533
3534                         if (!tle)
3535                         {
3536                                 /* No matching tlist item; look for a computable expression */
3537                                 Expr       *sortexpr = NULL;
3538
3539                                 foreach(j, ec->ec_members)
3540                                 {
3541                                         EquivalenceMember *em = (EquivalenceMember *) lfirst(j);
3542                                         List       *exprvars;
3543                                         ListCell   *k;
3544
3545                                         if (em->em_is_const)
3546                                                 continue;
3547                                         sortexpr = em->em_expr;
3548                                         exprvars = pull_var_clause((Node *) sortexpr,
3549                                                                                            PVC_RECURSE_AGGREGATES,
3550                                                                                            PVC_INCLUDE_PLACEHOLDERS);
3551                                         foreach(k, exprvars)
3552                                         {
3553                                                 if (!tlist_member_ignore_relabel(lfirst(k), tlist))
3554                                                         break;
3555                                         }
3556                                         list_free(exprvars);
3557                                         if (!k)
3558                                         {
3559                                                 pk_datatype = em->em_datatype;
3560                                                 break;  /* found usable expression */
3561                                         }
3562                                 }
3563                                 if (!j)
3564                                         elog(ERROR, "could not find pathkey item to sort");
3565
3566                                 /*
3567                                  * Do we need to insert a Result node?
3568                                  */
3569                                 if (!adjust_tlist_in_place &&
3570                                         !is_projection_capable_plan(lefttree))
3571                                 {
3572                                         /* copy needed so we don't modify input's tlist below */
3573                                         tlist = copyObject(tlist);
3574                                         lefttree = (Plan *) make_result(root, tlist, NULL,
3575                                                                                                         lefttree);
3576                                 }
3577
3578                                 /* Don't bother testing is_projection_capable_plan again */
3579                                 adjust_tlist_in_place = true;
3580
3581                                 /*
3582                                  * Add resjunk entry to input's tlist
3583                                  */
3584                                 tle = makeTargetEntry(sortexpr,
3585                                                                           list_length(tlist) + 1,
3586                                                                           NULL,
3587                                                                           true);
3588                                 tlist = lappend(tlist, tle);
3589                                 lefttree->targetlist = tlist;   /* just in case NIL before */
3590                         }
3591                 }
3592
3593                 /*
3594                  * Look up the correct sort operator from the PathKey's slightly
3595                  * abstracted representation.
3596                  */
3597                 sortop = get_opfamily_member(pathkey->pk_opfamily,
3598                                                                          pk_datatype,
3599                                                                          pk_datatype,
3600                                                                          pathkey->pk_strategy);
3601                 if (!OidIsValid(sortop))        /* should not happen */
3602                         elog(ERROR, "could not find member %d(%u,%u) of opfamily %u",
3603                                  pathkey->pk_strategy, pk_datatype, pk_datatype,
3604                                  pathkey->pk_opfamily);
3605
3606                 /*
3607                  * The column might already be selected as a sort key, if the pathkeys
3608                  * contain duplicate entries.  (This can happen in scenarios where
3609                  * multiple mergejoinable clauses mention the same var, for example.)
3610                  * So enter it only once in the sort arrays.
3611                  */
3612                 numsortkeys = add_sort_column(tle->resno,
3613                                                                           sortop,
3614                                                                           pathkey->pk_eclass->ec_collation,
3615                                                                           pathkey->pk_nulls_first,
3616                                                                           numsortkeys,
3617                                                                           sortColIdx, sortOperators,
3618                                                                           collations, nullsFirst);
3619         }
3620
3621         Assert(numsortkeys > 0);
3622
3623         /* Return results */
3624         *p_numsortkeys = numsortkeys;
3625         *p_sortColIdx = sortColIdx;
3626         *p_sortOperators = sortOperators;
3627         *p_collations = collations;
3628         *p_nullsFirst = nullsFirst;
3629
3630         return lefttree;
3631 }
3632
3633 /*
3634  * make_sort_from_pathkeys
3635  *        Create sort plan to sort according to given pathkeys
3636  *
3637  *        'lefttree' is the node which yields input tuples
3638  *        'pathkeys' is the list of pathkeys by which the result is to be sorted
3639  *        'limit_tuples' is the bound on the number of output tuples;
3640  *                              -1 if no bound
3641  */
3642 Sort *
3643 make_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree, List *pathkeys,
3644                                                 double limit_tuples)
3645 {
3646         int                     numsortkeys;
3647         AttrNumber *sortColIdx;
3648         Oid                *sortOperators;
3649         Oid                *collations;
3650         bool       *nullsFirst;
3651
3652         /* Compute sort column info, and adjust lefttree as needed */
3653         lefttree = prepare_sort_from_pathkeys(root, lefttree, pathkeys,
3654                                                                                   false,
3655                                                                                   &numsortkeys,
3656                                                                                   &sortColIdx,
3657                                                                                   &sortOperators,
3658                                                                                   &collations,
3659                                                                                   &nullsFirst);
3660
3661         /* Now build the Sort node */
3662         return make_sort(root, lefttree, numsortkeys,
3663                                          sortColIdx, sortOperators, collations,
3664                                          nullsFirst, limit_tuples);
3665 }
3666
3667 /*
3668  * make_sort_from_sortclauses
3669  *        Create sort plan to sort according to given sortclauses
3670  *
3671  *        'sortcls' is a list of SortGroupClauses
3672  *        'lefttree' is the node which yields input tuples
3673  */
3674 Sort *
3675 make_sort_from_sortclauses(PlannerInfo *root, List *sortcls, Plan *lefttree)
3676 {
3677         List       *sub_tlist = lefttree->targetlist;
3678         ListCell   *l;
3679         int                     numsortkeys;
3680         AttrNumber *sortColIdx;
3681         Oid                *sortOperators;
3682         Oid                *collations;
3683         bool       *nullsFirst;
3684
3685         /*
3686          * We will need at most list_length(sortcls) sort columns; possibly less
3687          */
3688         numsortkeys = list_length(sortcls);
3689         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
3690         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
3691         collations = (Oid *) palloc(numsortkeys * sizeof(Oid));
3692         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
3693
3694         numsortkeys = 0;
3695
3696         foreach(l, sortcls)
3697         {
3698                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(l);
3699                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, sub_tlist);
3700
3701                 /*
3702                  * Check for the possibility of duplicate order-by clauses --- the
3703                  * parser should have removed 'em, but no point in sorting
3704                  * redundantly.
3705                  */
3706                 numsortkeys = add_sort_column(tle->resno, sortcl->sortop,
3707                                                                           exprCollation((Node *) tle->expr),
3708                                                                           sortcl->nulls_first,
3709                                                                           numsortkeys,
3710                                                                           sortColIdx, sortOperators,
3711                                                                           collations, nullsFirst);
3712         }
3713
3714         Assert(numsortkeys > 0);
3715
3716         return make_sort(root, lefttree, numsortkeys,
3717                                          sortColIdx, sortOperators, collations,
3718                                          nullsFirst, -1.0);
3719 }
3720
3721 /*
3722  * make_sort_from_groupcols
3723  *        Create sort plan to sort based on grouping columns
3724  *
3725  * 'groupcls' is the list of SortGroupClauses
3726  * 'grpColIdx' gives the column numbers to use
3727  *
3728  * This might look like it could be merged with make_sort_from_sortclauses,
3729  * but presently we *must* use the grpColIdx[] array to locate sort columns,
3730  * because the child plan's tlist is not marked with ressortgroupref info
3731  * appropriate to the grouping node.  So, only the sort ordering info
3732  * is used from the SortGroupClause entries.
3733  */
3734 Sort *
3735 make_sort_from_groupcols(PlannerInfo *root,
3736                                                  List *groupcls,
3737                                                  AttrNumber *grpColIdx,
3738                                                  Plan *lefttree)
3739 {
3740         List       *sub_tlist = lefttree->targetlist;
3741         int                     grpno = 0;
3742         ListCell   *l;
3743         int                     numsortkeys;
3744         AttrNumber *sortColIdx;
3745         Oid                *sortOperators;
3746         Oid                *collations;
3747         bool       *nullsFirst;
3748
3749         /*
3750          * We will need at most list_length(groupcls) sort columns; possibly less
3751          */
3752         numsortkeys = list_length(groupcls);
3753         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
3754         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
3755         collations = (Oid *) palloc(numsortkeys * sizeof(Oid));
3756         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
3757
3758         numsortkeys = 0;
3759
3760         foreach(l, groupcls)
3761         {
3762                 SortGroupClause *grpcl = (SortGroupClause *) lfirst(l);
3763                 TargetEntry *tle = get_tle_by_resno(sub_tlist, grpColIdx[grpno]);
3764
3765                 /*
3766                  * Check for the possibility of duplicate group-by clauses --- the
3767                  * parser should have removed 'em, but no point in sorting
3768                  * redundantly.
3769                  */
3770                 numsortkeys = add_sort_column(tle->resno, grpcl->sortop,
3771                                                                           exprCollation((Node *) tle->expr),
3772                                                                           grpcl->nulls_first,
3773                                                                           numsortkeys,
3774                                                                           sortColIdx, sortOperators,
3775                                                                           collations, nullsFirst);
3776                 grpno++;
3777         }
3778
3779         Assert(numsortkeys > 0);
3780
3781         return make_sort(root, lefttree, numsortkeys,
3782                                          sortColIdx, sortOperators, collations,
3783                                          nullsFirst, -1.0);
3784 }
3785
3786 static Material *
3787 make_material(Plan *lefttree)
3788 {
3789         Material   *node = makeNode(Material);
3790         Plan       *plan = &node->plan;
3791
3792         /* cost should be inserted by caller */
3793         plan->targetlist = lefttree->targetlist;
3794         plan->qual = NIL;
3795         plan->lefttree = lefttree;
3796         plan->righttree = NULL;
3797
3798         return node;
3799 }
3800
3801 /*
3802  * materialize_finished_plan: stick a Material node atop a completed plan
3803  *
3804  * There are a couple of places where we want to attach a Material node
3805  * after completion of subquery_planner().      This currently requires hackery.
3806  * Since subquery_planner has already run SS_finalize_plan on the subplan
3807  * tree, we have to kluge up parameter lists for the Material node.
3808  * Possibly this could be fixed by postponing SS_finalize_plan processing
3809  * until setrefs.c is run?
3810  */
3811 Plan *
3812 materialize_finished_plan(Plan *subplan)
3813 {
3814         Plan       *matplan;
3815         Path            matpath;                /* dummy for result of cost_material */
3816
3817         matplan = (Plan *) make_material(subplan);
3818
3819         /* Set cost data */
3820         cost_material(&matpath,
3821                                   subplan->startup_cost,
3822                                   subplan->total_cost,
3823                                   subplan->plan_rows,
3824                                   subplan->plan_width);
3825         matplan->startup_cost = matpath.startup_cost;
3826         matplan->total_cost = matpath.total_cost;
3827         matplan->plan_rows = subplan->plan_rows;
3828         matplan->plan_width = subplan->plan_width;
3829
3830         /* parameter kluge --- see comments above */
3831         matplan->extParam = bms_copy(subplan->extParam);
3832         matplan->allParam = bms_copy(subplan->allParam);
3833
3834         return matplan;
3835 }
3836
3837 Agg *
3838 make_agg(PlannerInfo *root, List *tlist, List *qual,
3839                  AggStrategy aggstrategy, const AggClauseCosts *aggcosts,
3840                  int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators,
3841                  long numGroups,
3842                  Plan *lefttree)
3843 {
3844         Agg                *node = makeNode(Agg);
3845         Plan       *plan = &node->plan;
3846         Path            agg_path;               /* dummy for result of cost_agg */
3847         QualCost        qual_cost;
3848
3849         node->aggstrategy = aggstrategy;
3850         node->numCols = numGroupCols;
3851         node->grpColIdx = grpColIdx;
3852         node->grpOperators = grpOperators;
3853         node->numGroups = numGroups;
3854
3855         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3856         cost_agg(&agg_path, root,
3857                          aggstrategy, aggcosts,
3858                          numGroupCols, numGroups,
3859                          lefttree->startup_cost,
3860                          lefttree->total_cost,
3861                          lefttree->plan_rows);
3862         plan->startup_cost = agg_path.startup_cost;
3863         plan->total_cost = agg_path.total_cost;
3864
3865         /*
3866          * We will produce a single output tuple if not grouping, and a tuple per
3867          * group otherwise.
3868          */
3869         if (aggstrategy == AGG_PLAIN)
3870                 plan->plan_rows = 1;
3871         else
3872                 plan->plan_rows = numGroups;
3873
3874         /*
3875          * We also need to account for the cost of evaluation of the qual (ie, the
3876          * HAVING clause) and the tlist.  Note that cost_qual_eval doesn't charge
3877          * anything for Aggref nodes; this is okay since they are really
3878          * comparable to Vars.
3879          *
3880          * See notes in grouping_planner about why only make_agg, make_windowagg
3881          * and make_group worry about tlist eval cost.
3882          */
3883         if (qual)
3884         {
3885                 cost_qual_eval(&qual_cost, qual, root);
3886                 plan->startup_cost += qual_cost.startup;
3887                 plan->total_cost += qual_cost.startup;
3888                 plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3889         }
3890         cost_qual_eval(&qual_cost, tlist, root);
3891         plan->startup_cost += qual_cost.startup;
3892         plan->total_cost += qual_cost.startup;
3893         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3894
3895         plan->qual = qual;
3896         plan->targetlist = tlist;
3897         plan->lefttree = lefttree;
3898         plan->righttree = NULL;
3899
3900         return node;
3901 }
3902
3903 WindowAgg *
3904 make_windowagg(PlannerInfo *root, List *tlist,
3905                            List *windowFuncs, Index winref,
3906                            int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
3907                            int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
3908                            int frameOptions, Node *startOffset, Node *endOffset,
3909                            Plan *lefttree)
3910 {
3911         WindowAgg  *node = makeNode(WindowAgg);
3912         Plan       *plan = &node->plan;
3913         Path            windowagg_path; /* dummy for result of cost_windowagg */
3914         QualCost        qual_cost;
3915
3916         node->winref = winref;
3917         node->partNumCols = partNumCols;
3918         node->partColIdx = partColIdx;
3919         node->partOperators = partOperators;
3920         node->ordNumCols = ordNumCols;
3921         node->ordColIdx = ordColIdx;
3922         node->ordOperators = ordOperators;
3923         node->frameOptions = frameOptions;
3924         node->startOffset = startOffset;
3925         node->endOffset = endOffset;
3926
3927         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3928         cost_windowagg(&windowagg_path, root,
3929                                    windowFuncs, partNumCols, ordNumCols,
3930                                    lefttree->startup_cost,
3931                                    lefttree->total_cost,
3932                                    lefttree->plan_rows);
3933         plan->startup_cost = windowagg_path.startup_cost;
3934         plan->total_cost = windowagg_path.total_cost;
3935
3936         /*
3937          * We also need to account for the cost of evaluation of the tlist.
3938          *
3939          * See notes in grouping_planner about why only make_agg, make_windowagg
3940          * and make_group worry about tlist eval cost.
3941          */
3942         cost_qual_eval(&qual_cost, tlist, root);
3943         plan->startup_cost += qual_cost.startup;
3944         plan->total_cost += qual_cost.startup;
3945         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3946
3947         plan->targetlist = tlist;
3948         plan->lefttree = lefttree;
3949         plan->righttree = NULL;
3950         /* WindowAgg nodes never have a qual clause */
3951         plan->qual = NIL;
3952
3953         return node;
3954 }
3955
3956 Group *
3957 make_group(PlannerInfo *root,
3958                    List *tlist,
3959                    List *qual,
3960                    int numGroupCols,
3961                    AttrNumber *grpColIdx,
3962                    Oid *grpOperators,
3963                    double numGroups,
3964                    Plan *lefttree)
3965 {
3966         Group      *node = makeNode(Group);
3967         Plan       *plan = &node->plan;
3968         Path            group_path;             /* dummy for result of cost_group */
3969         QualCost        qual_cost;
3970
3971         node->numCols = numGroupCols;
3972         node->grpColIdx = grpColIdx;
3973         node->grpOperators = grpOperators;
3974
3975         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3976         cost_group(&group_path, root,
3977                            numGroupCols, numGroups,
3978                            lefttree->startup_cost,
3979                            lefttree->total_cost,
3980                            lefttree->plan_rows);
3981         plan->startup_cost = group_path.startup_cost;
3982         plan->total_cost = group_path.total_cost;
3983
3984         /* One output tuple per estimated result group */
3985         plan->plan_rows = numGroups;
3986
3987         /*
3988          * We also need to account for the cost of evaluation of the qual (ie, the
3989          * HAVING clause) and the tlist.
3990          *
3991          * XXX this double-counts the cost of evaluation of any expressions used
3992          * for grouping, since in reality those will have been evaluated at a
3993          * lower plan level and will only be copied by the Group node. Worth
3994          * fixing?
3995          *
3996          * See notes in grouping_planner about why only make_agg, make_windowagg
3997          * and make_group worry about tlist eval cost.
3998          */
3999         if (qual)
4000         {
4001                 cost_qual_eval(&qual_cost, qual, root);
4002                 plan->startup_cost += qual_cost.startup;
4003                 plan->total_cost += qual_cost.startup;
4004                 plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
4005         }
4006         cost_qual_eval(&qual_cost, tlist, root);
4007         plan->startup_cost += qual_cost.startup;
4008         plan->total_cost += qual_cost.startup;
4009         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
4010
4011         plan->qual = qual;
4012         plan->targetlist = tlist;
4013         plan->lefttree = lefttree;
4014         plan->righttree = NULL;
4015
4016         return node;
4017 }
4018
4019 /*
4020  * distinctList is a list of SortGroupClauses, identifying the targetlist items
4021  * that should be considered by the Unique filter.      The input path must
4022  * already be sorted accordingly.
4023  */
4024 Unique *
4025 make_unique(Plan *lefttree, List *distinctList)
4026 {
4027         Unique     *node = makeNode(Unique);
4028         Plan       *plan = &node->plan;
4029         int                     numCols = list_length(distinctList);
4030         int                     keyno = 0;
4031         AttrNumber *uniqColIdx;
4032         Oid                *uniqOperators;
4033         ListCell   *slitem;
4034
4035         copy_plan_costsize(plan, lefttree);
4036
4037         /*
4038          * Charge one cpu_operator_cost per comparison per input tuple. We assume
4039          * all columns get compared at most of the tuples.      (XXX probably this is
4040          * an overestimate.)
4041          */
4042         plan->total_cost += cpu_operator_cost * plan->plan_rows * numCols;
4043
4044         /*
4045          * plan->plan_rows is left as a copy of the input subplan's plan_rows; ie,
4046          * we assume the filter removes nothing.  The caller must alter this if he
4047          * has a better idea.
4048          */
4049
4050         plan->targetlist = lefttree->targetlist;
4051         plan->qual = NIL;
4052         plan->lefttree = lefttree;
4053         plan->righttree = NULL;
4054
4055         /*
4056          * convert SortGroupClause list into arrays of attr indexes and equality
4057          * operators, as wanted by executor
4058          */
4059         Assert(numCols > 0);
4060         uniqColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
4061         uniqOperators = (Oid *) palloc(sizeof(Oid) * numCols);
4062
4063         foreach(slitem, distinctList)
4064         {
4065                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
4066                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, plan->targetlist);
4067
4068                 uniqColIdx[keyno] = tle->resno;
4069                 uniqOperators[keyno] = sortcl->eqop;
4070                 Assert(OidIsValid(uniqOperators[keyno]));
4071                 keyno++;
4072         }
4073
4074         node->numCols = numCols;
4075         node->uniqColIdx = uniqColIdx;
4076         node->uniqOperators = uniqOperators;
4077
4078         return node;
4079 }
4080
4081 /*
4082  * distinctList is a list of SortGroupClauses, identifying the targetlist
4083  * items that should be considered by the SetOp filter.  The input path must
4084  * already be sorted accordingly.
4085  */
4086 SetOp *
4087 make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
4088                    List *distinctList, AttrNumber flagColIdx, int firstFlag,
4089                    long numGroups, double outputRows)
4090 {
4091         SetOp      *node = makeNode(SetOp);
4092         Plan       *plan = &node->plan;
4093         int                     numCols = list_length(distinctList);
4094         int                     keyno = 0;
4095         AttrNumber *dupColIdx;
4096         Oid                *dupOperators;
4097         ListCell   *slitem;
4098
4099         copy_plan_costsize(plan, lefttree);
4100         plan->plan_rows = outputRows;
4101
4102         /*
4103          * Charge one cpu_operator_cost per comparison per input tuple. We assume
4104          * all columns get compared at most of the tuples.
4105          */
4106         plan->total_cost += cpu_operator_cost * lefttree->plan_rows * numCols;
4107
4108         plan->targetlist = lefttree->targetlist;
4109         plan->qual = NIL;
4110         plan->lefttree = lefttree;
4111         plan->righttree = NULL;
4112
4113         /*
4114          * convert SortGroupClause list into arrays of attr indexes and equality
4115          * operators, as wanted by executor
4116          */
4117         Assert(numCols > 0);
4118         dupColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
4119         dupOperators = (Oid *) palloc(sizeof(Oid) * numCols);
4120
4121         foreach(slitem, distinctList)
4122         {
4123                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
4124                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, plan->targetlist);
4125
4126                 dupColIdx[keyno] = tle->resno;
4127                 dupOperators[keyno] = sortcl->eqop;
4128                 Assert(OidIsValid(dupOperators[keyno]));
4129                 keyno++;
4130         }
4131
4132         node->cmd = cmd;
4133         node->strategy = strategy;
4134         node->numCols = numCols;
4135         node->dupColIdx = dupColIdx;
4136         node->dupOperators = dupOperators;
4137         node->flagColIdx = flagColIdx;
4138         node->firstFlag = firstFlag;
4139         node->numGroups = numGroups;
4140
4141         return node;
4142 }
4143
4144 /*
4145  * make_lockrows
4146  *        Build a LockRows plan node
4147  */
4148 LockRows *
4149 make_lockrows(Plan *lefttree, List *rowMarks, int epqParam)
4150 {
4151         LockRows   *node = makeNode(LockRows);
4152         Plan       *plan = &node->plan;
4153
4154         copy_plan_costsize(plan, lefttree);
4155
4156         /* charge cpu_tuple_cost to reflect locking costs (underestimate?) */
4157         plan->total_cost += cpu_tuple_cost * plan->plan_rows;
4158
4159         plan->targetlist = lefttree->targetlist;
4160         plan->qual = NIL;
4161         plan->lefttree = lefttree;
4162         plan->righttree = NULL;
4163
4164         node->rowMarks = rowMarks;
4165         node->epqParam = epqParam;
4166
4167         return node;
4168 }
4169
4170 /*
4171  * Note: offset_est and count_est are passed in to save having to repeat
4172  * work already done to estimate the values of the limitOffset and limitCount
4173  * expressions.  Their values are as returned by preprocess_limit (0 means
4174  * "not relevant", -1 means "couldn't estimate").  Keep the code below in sync
4175  * with that function!
4176  */
4177 Limit *
4178 make_limit(Plan *lefttree, Node *limitOffset, Node *limitCount,
4179                    int64 offset_est, int64 count_est)
4180 {
4181         Limit      *node = makeNode(Limit);
4182         Plan       *plan = &node->plan;
4183
4184         copy_plan_costsize(plan, lefttree);
4185
4186         /*
4187          * Adjust the output rows count and costs according to the offset/limit.
4188          * This is only a cosmetic issue if we are at top level, but if we are
4189          * building a subquery then it's important to report correct info to the
4190          * outer planner.
4191          *
4192          * When the offset or count couldn't be estimated, use 10% of the
4193          * estimated number of rows emitted from the subplan.
4194          */
4195         if (offset_est != 0)
4196         {
4197                 double          offset_rows;
4198
4199                 if (offset_est > 0)
4200                         offset_rows = (double) offset_est;
4201                 else
4202                         offset_rows = clamp_row_est(lefttree->plan_rows * 0.10);
4203                 if (offset_rows > plan->plan_rows)
4204                         offset_rows = plan->plan_rows;
4205                 if (plan->plan_rows > 0)
4206                         plan->startup_cost +=
4207                                 (plan->total_cost - plan->startup_cost)
4208                                 * offset_rows / plan->plan_rows;
4209                 plan->plan_rows -= offset_rows;
4210                 if (plan->plan_rows < 1)
4211                         plan->plan_rows = 1;
4212         }
4213
4214         if (count_est != 0)
4215         {
4216                 double          count_rows;
4217
4218                 if (count_est > 0)
4219                         count_rows = (double) count_est;
4220                 else
4221                         count_rows = clamp_row_est(lefttree->plan_rows * 0.10);
4222                 if (count_rows > plan->plan_rows)
4223                         count_rows = plan->plan_rows;
4224                 if (plan->plan_rows > 0)
4225                         plan->total_cost = plan->startup_cost +
4226                                 (plan->total_cost - plan->startup_cost)
4227                                 * count_rows / plan->plan_rows;
4228                 plan->plan_rows = count_rows;
4229                 if (plan->plan_rows < 1)
4230                         plan->plan_rows = 1;
4231         }
4232
4233         plan->targetlist = lefttree->targetlist;
4234         plan->qual = NIL;
4235         plan->lefttree = lefttree;
4236         plan->righttree = NULL;
4237
4238         node->limitOffset = limitOffset;
4239         node->limitCount = limitCount;
4240
4241         return node;
4242 }
4243
4244 /*
4245  * make_result
4246  *        Build a Result plan node
4247  *
4248  * If we have a subplan, assume that any evaluation costs for the gating qual
4249  * were already factored into the subplan's startup cost, and just copy the
4250  * subplan cost.  If there's no subplan, we should include the qual eval
4251  * cost.  In either case, tlist eval cost is not to be included here.
4252  */
4253 Result *
4254 make_result(PlannerInfo *root,
4255                         List *tlist,
4256                         Node *resconstantqual,
4257                         Plan *subplan)
4258 {
4259         Result     *node = makeNode(Result);
4260         Plan       *plan = &node->plan;
4261
4262         if (subplan)
4263                 copy_plan_costsize(plan, subplan);
4264         else
4265         {
4266                 plan->startup_cost = 0;
4267                 plan->total_cost = cpu_tuple_cost;
4268                 plan->plan_rows = 1;    /* wrong if we have a set-valued function? */
4269                 plan->plan_width = 0;   /* XXX is it worth being smarter? */
4270                 if (resconstantqual)
4271                 {
4272                         QualCost        qual_cost;
4273
4274                         cost_qual_eval(&qual_cost, (List *) resconstantqual, root);
4275                         /* resconstantqual is evaluated once at startup */
4276                         plan->startup_cost += qual_cost.startup + qual_cost.per_tuple;
4277                         plan->total_cost += qual_cost.startup + qual_cost.per_tuple;
4278                 }
4279         }
4280
4281         plan->targetlist = tlist;
4282         plan->qual = NIL;
4283         plan->lefttree = subplan;
4284         plan->righttree = NULL;
4285         node->resconstantqual = resconstantqual;
4286
4287         return node;
4288 }
4289
4290 /*
4291  * make_modifytable
4292  *        Build a ModifyTable plan node
4293  *
4294  * Currently, we don't charge anything extra for the actual table modification
4295  * work, nor for the RETURNING expressions if any.      It would only be window
4296  * dressing, since these are always top-level nodes and there is no way for
4297  * the costs to change any higher-level planning choices.  But we might want
4298  * to make it look better sometime.
4299  */
4300 ModifyTable *
4301 make_modifytable(CmdType operation, bool canSetTag,
4302                                  List *resultRelations,
4303                                  List *subplans, List *returningLists,
4304                                  List *rowMarks, int epqParam)
4305 {
4306         ModifyTable *node = makeNode(ModifyTable);
4307         Plan       *plan = &node->plan;
4308         double          total_size;
4309         ListCell   *subnode;
4310
4311         Assert(list_length(resultRelations) == list_length(subplans));
4312         Assert(returningLists == NIL ||
4313                    list_length(resultRelations) == list_length(returningLists));
4314
4315         /*
4316          * Compute cost as sum of subplan costs.
4317          */
4318         plan->startup_cost = 0;
4319         plan->total_cost = 0;
4320         plan->plan_rows = 0;
4321         total_size = 0;
4322         foreach(subnode, subplans)
4323         {
4324                 Plan       *subplan = (Plan *) lfirst(subnode);
4325
4326                 if (subnode == list_head(subplans))             /* first node? */
4327                         plan->startup_cost = subplan->startup_cost;
4328                 plan->total_cost += subplan->total_cost;
4329                 plan->plan_rows += subplan->plan_rows;
4330                 total_size += subplan->plan_width * subplan->plan_rows;
4331         }
4332         if (plan->plan_rows > 0)
4333                 plan->plan_width = rint(total_size / plan->plan_rows);
4334         else
4335                 plan->plan_width = 0;
4336
4337         node->plan.lefttree = NULL;
4338         node->plan.righttree = NULL;
4339         node->plan.qual = NIL;
4340
4341         /*
4342          * Set up the visible plan targetlist as being the same as the first
4343          * RETURNING list.      This is for the use of EXPLAIN; the executor won't pay
4344          * any attention to the targetlist.
4345          */
4346         if (returningLists)
4347                 node->plan.targetlist = copyObject(linitial(returningLists));
4348         else
4349                 node->plan.targetlist = NIL;
4350
4351         node->operation = operation;
4352         node->canSetTag = canSetTag;
4353         node->resultRelations = resultRelations;
4354         node->resultRelIndex = -1;      /* will be set correctly in setrefs.c */
4355         node->plans = subplans;
4356         node->returningLists = returningLists;
4357         node->rowMarks = rowMarks;
4358         node->epqParam = epqParam;
4359
4360         return node;
4361 }
4362
4363 /*
4364  * is_projection_capable_plan
4365  *              Check whether a given Plan node is able to do projection.
4366  */
4367 bool
4368 is_projection_capable_plan(Plan *plan)
4369 {
4370         /* Most plan types can project, so just list the ones that can't */
4371         switch (nodeTag(plan))
4372         {
4373                 case T_Hash:
4374                 case T_Material:
4375                 case T_Sort:
4376                 case T_Unique:
4377                 case T_SetOp:
4378                 case T_LockRows:
4379                 case T_Limit:
4380                 case T_ModifyTable:
4381                 case T_Append:
4382                 case T_MergeAppend:
4383                 case T_RecursiveUnion:
4384                         return false;
4385                 default:
4386                         break;
4387         }
4388         return true;
4389 }