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) 1996-2009, PostgreSQL Global Development Group
   9  * Portions Copyright (c) 1994, Regents of the University of California
  10  *
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.265 2009/10/12 18:10:45 tgl Exp $
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <limits.h>
  20 #include <math.h>
  21
  22 #include "access/skey.h"
  23 #include "nodes/makefuncs.h"
  24 #include "nodes/nodeFuncs.h"
  25 #include "optimizer/clauses.h"
  26 #include "optimizer/cost.h"
  27 #include "optimizer/plancat.h"
  28 #include "optimizer/planmain.h"
  29 #include "optimizer/predtest.h"
  30 #include "optimizer/restrictinfo.h"
  31 #include "optimizer/tlist.h"
  32 #include "optimizer/var.h"
  33 #include "parser/parse_clause.h"
  34 #include "parser/parsetree.h"
  35 #include "utils/lsyscache.h"
  36
  37
  38 static Plan *create_scan_plan(PlannerInfo *root, Path *best_path);
  39 static List *build_relation_tlist(RelOptInfo *rel);
  40 static bool use_physical_tlist(PlannerInfo *root, RelOptInfo *rel);
  41 static void disuse_physical_tlist(Plan *plan, Path *path);
  42 static Plan *create_gating_plan(PlannerInfo *root, Plan *plan, List *quals);
  43 static Plan *create_join_plan(PlannerInfo *root, JoinPath *best_path);
  44 static Plan *create_append_plan(PlannerInfo *root, AppendPath *best_path);
  45 static Result *create_result_plan(PlannerInfo *root, ResultPath *best_path);
  46 static Material *create_material_plan(PlannerInfo *root, MaterialPath *best_path);
  47 static Plan *create_unique_plan(PlannerInfo *root, UniquePath *best_path);
  48 static SeqScan *create_seqscan_plan(PlannerInfo *root, Path *best_path,
  49                                         List *tlist, List *scan_clauses);
  50 static IndexScan *create_indexscan_plan(PlannerInfo *root, IndexPath *best_path,
  51                                           List *tlist, List *scan_clauses);
  52 static BitmapHeapScan *create_bitmap_scan_plan(PlannerInfo *root,
  53                                                 BitmapHeapPath *best_path,
  54                                                 List *tlist, List *scan_clauses);
  55 static Plan *create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
  56                                           List **qual, List **indexqual);
  57 static TidScan *create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
  58                                         List *tlist, List *scan_clauses);
  59 static SubqueryScan *create_subqueryscan_plan(PlannerInfo *root, Path *best_path,
  60                                                  List *tlist, List *scan_clauses);
  61 static FunctionScan *create_functionscan_plan(PlannerInfo *root, Path *best_path,
  62                                                  List *tlist, List *scan_clauses);
  63 static ValuesScan *create_valuesscan_plan(PlannerInfo *root, Path *best_path,
  64                                            List *tlist, List *scan_clauses);
  65 static CteScan *create_ctescan_plan(PlannerInfo *root, Path *best_path,
  66                                         List *tlist, List *scan_clauses);
  67 static WorkTableScan *create_worktablescan_plan(PlannerInfo *root, Path *best_path,
  68                                                   List *tlist, List *scan_clauses);
  69 static NestLoop *create_nestloop_plan(PlannerInfo *root, NestPath *best_path,
  70                                          Plan *outer_plan, Plan *inner_plan);
  71 static MergeJoin *create_mergejoin_plan(PlannerInfo *root, MergePath *best_path,
  72                                           Plan *outer_plan, Plan *inner_plan);
  73 static HashJoin *create_hashjoin_plan(PlannerInfo *root, HashPath *best_path,
  74                                          Plan *outer_plan, Plan *inner_plan);
  75 static List *fix_indexqual_references(List *indexquals, IndexPath *index_path);
  76 static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index);
  77 static List *get_switched_clauses(List *clauses, Relids outerrelids);
  78 static List *order_qual_clauses(PlannerInfo *root, List *clauses);
  79 static void copy_path_costsize(Plan *dest, Path *src);
  80 static void copy_plan_costsize(Plan *dest, Plan *src);
  81 static SeqScan *make_seqscan(List *qptlist, List *qpqual, Index scanrelid);
  82 static IndexScan *make_indexscan(List *qptlist, List *qpqual, Index scanrelid,
  83                            Oid indexid, List *indexqual, List *indexqualorig,
  84                            ScanDirection indexscandir);
  85 static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
  86                                           List *indexqual,
  87                                           List *indexqualorig);
  88 static BitmapHeapScan *make_bitmap_heapscan(List *qptlist,
  89                                          List *qpqual,
  90                                          Plan *lefttree,
  91                                          List *bitmapqualorig,
  92                                          Index scanrelid);
  93 static TidScan *make_tidscan(List *qptlist, List *qpqual, Index scanrelid,
  94                          List *tidquals);
  95 static FunctionScan *make_functionscan(List *qptlist, List *qpqual,
  96                                   Index scanrelid, Node *funcexpr, List *funccolnames,
  97                                   List *funccoltypes, List *funccoltypmods);
  98 static ValuesScan *make_valuesscan(List *qptlist, List *qpqual,
  99                                 Index scanrelid, List *values_lists);
 100 static CteScan *make_ctescan(List *qptlist, List *qpqual,
 101                          Index scanrelid, int ctePlanId, int cteParam);
 102 static WorkTableScan *make_worktablescan(List *qptlist, List *qpqual,
 103                                    Index scanrelid, int wtParam);
 104 static BitmapAnd *make_bitmap_and(List *bitmapplans);
 105 static BitmapOr *make_bitmap_or(List *bitmapplans);
 106 static NestLoop *make_nestloop(List *tlist,
 107                           List *joinclauses, List *otherclauses,
 108                           Plan *lefttree, Plan *righttree,
 109                           JoinType jointype);
 110 static HashJoin *make_hashjoin(List *tlist,
 111                           List *joinclauses, List *otherclauses,
 112                           List *hashclauses,
 113                           Plan *lefttree, Plan *righttree,
 114                           JoinType jointype);
 115 static Hash *make_hash(Plan *lefttree,
 116                   Oid skewTable,
 117                   AttrNumber skewColumn,
 118                   Oid skewColType,
 119                   int32 skewColTypmod);
 120 static MergeJoin *make_mergejoin(List *tlist,
 121                            List *joinclauses, List *otherclauses,
 122                            List *mergeclauses,
 123                            Oid *mergefamilies,
 124                            int *mergestrategies,
 125                            bool *mergenullsfirst,
 126                            Plan *lefttree, Plan *righttree,
 127                            JoinType jointype);
 128 static Sort *make_sort(PlannerInfo *root, Plan *lefttree, int numCols,
 129                   AttrNumber *sortColIdx, Oid *sortOperators, bool *nullsFirst,
 130                   double limit_tuples);
 131 static Material *make_material(Plan *lefttree);
 132
 133
 134 /*
 135  * create_plan
 136  *        Creates the access plan for a query by tracing backwards through the
 137  *        desired chain of pathnodes, starting at the node 'best_path'.  For
 138  *        every pathnode found, we create a corresponding plan node containing
 139  *        appropriate id, target list, and qualification information.
 140  *
 141  *        The tlists and quals in the plan tree are still in planner format,
 142  *        ie, Vars still correspond to the parser's numbering.  This will be
 143  *        fixed later by setrefs.c.
 144  *
 145  *        best_path is the best access path
 146  *
 147  *        Returns a Plan tree.
 148  */
 149 Plan *
 150 create_plan(PlannerInfo *root, Path *best_path)
 151 {
 152         Plan       *plan;
 153
 154         switch (best_path->pathtype)
 155         {
 156                 case T_SeqScan:
 157                 case T_IndexScan:
 158                 case T_BitmapHeapScan:
 159                 case T_TidScan:
 160                 case T_SubqueryScan:
 161                 case T_FunctionScan:
 162                 case T_ValuesScan:
 163                 case T_CteScan:
 164                 case T_WorkTableScan:
 165                         plan = create_scan_plan(root, best_path);
 166                         break;
 167                 case T_Join:
 168                         /* this is only used for no-op joins */
 169                         Assert(IsA(best_path, NoOpPath));
 170                         plan = create_plan(root, ((NoOpPath *) best_path)->subpath);
 171                         break;
 172                 case T_HashJoin:
 173                 case T_MergeJoin:
 174                 case T_NestLoop:
 175                         plan = create_join_plan(root,
 176                                                                         (JoinPath *) best_path);
 177                         break;
 178                 case T_Append:
 179                         plan = create_append_plan(root,
 180                                                                           (AppendPath *) best_path);
 181                         break;
 182                 case T_Result:
 183                         plan = (Plan *) create_result_plan(root,
 184                                                                                            (ResultPath *) best_path);
 185                         break;
 186                 case T_Material:
 187                         plan = (Plan *) create_material_plan(root,
 188                                                                                                  (MaterialPath *) best_path);
 189                         break;
 190                 case T_Unique:
 191                         plan = create_unique_plan(root,
 192                                                                           (UniquePath *) best_path);
 193                         break;
 194                 default:
 195                         elog(ERROR, "unrecognized node type: %d",
 196                                  (int) best_path->pathtype);
 197                         plan = NULL;            /* keep compiler quiet */
 198                         break;
 199         }
 200
 201         return plan;
 202 }
 203
 204 /*
 205  * create_scan_plan
 206  *       Create a scan plan for the parent relation of 'best_path'.
 207  */
 208 static Plan *
 209 create_scan_plan(PlannerInfo *root, Path *best_path)
 210 {
 211         RelOptInfo *rel = best_path->parent;
 212         List       *tlist;
 213         List       *scan_clauses;
 214         Plan       *plan;
 215
 216         /*
 217          * For table scans, rather than using the relation targetlist (which is
 218          * only those Vars actually needed by the query), we prefer to generate a
 219          * tlist containing all Vars in order.  This will allow the executor to
 220          * optimize away projection of the table tuples, if possible.  (Note that
 221          * planner.c may replace the tlist we generate here, forcing projection to
 222          * occur.)
 223          */
 224         if (use_physical_tlist(root, rel))
 225         {
 226                 tlist = build_physical_tlist(root, rel);
 227                 /* if fail because of dropped cols, use regular method */
 228                 if (tlist == NIL)
 229                         tlist = build_relation_tlist(rel);
 230         }
 231         else
 232                 tlist = build_relation_tlist(rel);
 233
 234         /*
 235          * Extract the relevant restriction clauses from the parent relation. The
 236          * executor must apply all these restrictions during the scan, except for
 237          * pseudoconstants which we'll take care of below.
 238          */
 239         scan_clauses = rel->baserestrictinfo;
 240
 241         switch (best_path->pathtype)
 242         {
 243                 case T_SeqScan:
 244                         plan = (Plan *) create_seqscan_plan(root,
 245                                                                                                 best_path,
 246                                                                                                 tlist,
 247                                                                                                 scan_clauses);
 248                         break;
 249
 250                 case T_IndexScan:
 251                         plan = (Plan *) create_indexscan_plan(root,
 252                                                                                                   (IndexPath *) best_path,
 253                                                                                                   tlist,
 254                                                                                                   scan_clauses);
 255                         break;
 256
 257                 case T_BitmapHeapScan:
 258                         plan = (Plan *) create_bitmap_scan_plan(root,
 259                                                                                                 (BitmapHeapPath *) best_path,
 260                                                                                                         tlist,
 261                                                                                                         scan_clauses);
 262                         break;
 263
 264                 case T_TidScan:
 265                         plan = (Plan *) create_tidscan_plan(root,
 266                                                                                                 (TidPath *) best_path,
 267                                                                                                 tlist,
 268                                                                                                 scan_clauses);
 269                         break;
 270
 271                 case T_SubqueryScan:
 272                         plan = (Plan *) create_subqueryscan_plan(root,
 273                                                                                                          best_path,
 274                                                                                                          tlist,
 275                                                                                                          scan_clauses);
 276                         break;
 277
 278                 case T_FunctionScan:
 279                         plan = (Plan *) create_functionscan_plan(root,
 280                                                                                                          best_path,
 281                                                                                                          tlist,
 282                                                                                                          scan_clauses);
 283                         break;
 284
 285                 case T_ValuesScan:
 286                         plan = (Plan *) create_valuesscan_plan(root,
 287                                                                                                    best_path,
 288                                                                                                    tlist,
 289                                                                                                    scan_clauses);
 290                         break;
 291
 292                 case T_CteScan:
 293                         plan = (Plan *) create_ctescan_plan(root,
 294                                                                                                 best_path,
 295                                                                                                 tlist,
 296                                                                                                 scan_clauses);
 297                         break;
 298
 299                 case T_WorkTableScan:
 300                         plan = (Plan *) create_worktablescan_plan(root,
 301                                                                                                           best_path,
 302                                                                                                           tlist,
 303                                                                                                           scan_clauses);
 304                         break;
 305
 306                 default:
 307                         elog(ERROR, "unrecognized node type: %d",
 308                                  (int) best_path->pathtype);
 309                         plan = NULL;            /* keep compiler quiet */
 310                         break;
 311         }
 312
 313         /*
 314          * If there are any pseudoconstant clauses attached to this node, insert a
 315          * gating Result node that evaluates the pseudoconstants as one-time
 316          * quals.
 317          */
 318         if (root->hasPseudoConstantQuals)
 319                 plan = create_gating_plan(root, plan, scan_clauses);
 320
 321         return plan;
 322 }
 323
 324 /*
 325  * Build a target list (ie, a list of TargetEntry) for a relation.
 326  */
 327 static List *
 328 build_relation_tlist(RelOptInfo *rel)
 329 {
 330         List       *tlist = NIL;
 331         int                     resno = 1;
 332         ListCell   *v;
 333
 334         foreach(v, rel->reltargetlist)
 335         {
 336                 /* Do we really need to copy here?      Not sure */
 337                 Node       *node = (Node *) copyObject(lfirst(v));
 338
 339                 tlist = lappend(tlist, makeTargetEntry((Expr *) node,
 340                                                                                            resno,
 341                                                                                            NULL,
 342                                                                                            false));
 343                 resno++;
 344         }
 345         return tlist;
 346 }
 347
 348 /*
 349  * use_physical_tlist
 350  *              Decide whether to use a tlist matching relation structure,
 351  *              rather than only those Vars actually referenced.
 352  */
 353 static bool
 354 use_physical_tlist(PlannerInfo *root, RelOptInfo *rel)
 355 {
 356         int                     i;
 357         ListCell   *lc;
 358
 359         /*
 360          * We can do this for real relation scans, subquery scans, function scans,
 361          * values scans, and CTE scans (but not for, eg, joins).
 362          */
 363         if (rel->rtekind != RTE_RELATION &&
 364                 rel->rtekind != RTE_SUBQUERY &&
 365                 rel->rtekind != RTE_FUNCTION &&
 366                 rel->rtekind != RTE_VALUES &&
 367                 rel->rtekind != RTE_CTE)
 368                 return false;
 369
 370         /*
 371          * Can't do it with inheritance cases either (mainly because Append
 372          * doesn't project).
 373          */
 374         if (rel->reloptkind != RELOPT_BASEREL)
 375                 return false;
 376
 377         /*
 378          * Can't do it if any system columns or whole-row Vars are requested.
 379          * (This could possibly be fixed but would take some fragile assumptions
 380          * in setrefs.c, I think.)
 381          */
 382         for (i = rel->min_attr; i <= 0; i++)
 383         {
 384                 if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
 385                         return false;
 386         }
 387
 388         /*
 389          * Can't do it if the rel is required to emit any placeholder expressions,
 390          * either.
 391          */
 392         foreach(lc, root->placeholder_list)
 393         {
 394                 PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
 395
 396                 if (bms_nonempty_difference(phinfo->ph_needed, rel->relids) &&
 397                         bms_is_subset(phinfo->ph_eval_at, rel->relids))
 398                         return false;
 399         }
 400
 401         return true;
 402 }
 403
 404 /*
 405  * disuse_physical_tlist
 406  *              Switch a plan node back to emitting only Vars actually referenced.
 407  *
 408  * If the plan node immediately above a scan would prefer to get only
 409  * needed Vars and not a physical tlist, it must call this routine to
 410  * undo the decision made by use_physical_tlist().      Currently, Hash, Sort,
 411  * and Material nodes want this, so they don't have to store useless columns.
 412  */
 413 static void
 414 disuse_physical_tlist(Plan *plan, Path *path)
 415 {
 416         /* Only need to undo it for path types handled by create_scan_plan() */
 417         switch (path->pathtype)
 418         {
 419                 case T_SeqScan:
 420                 case T_IndexScan:
 421                 case T_BitmapHeapScan:
 422                 case T_TidScan:
 423                 case T_SubqueryScan:
 424                 case T_FunctionScan:
 425                 case T_ValuesScan:
 426                 case T_CteScan:
 427                 case T_WorkTableScan:
 428                         plan->targetlist = build_relation_tlist(path->parent);
 429                         break;
 430                 default:
 431                         break;
 432         }
 433 }
 434
 435 /*
 436  * create_gating_plan
 437  *        Deal with pseudoconstant qual clauses
 438  *
 439  * If the node's quals list includes any pseudoconstant quals, put them
 440  * into a gating Result node atop the already-built plan.  Otherwise,
 441  * return the plan as-is.
 442  *
 443  * Note that we don't change cost or size estimates when doing gating.
 444  * The costs of qual eval were already folded into the plan's startup cost.
 445  * Leaving the size alone amounts to assuming that the gating qual will
 446  * succeed, which is the conservative estimate for planning upper queries.
 447  * We certainly don't want to assume the output size is zero (unless the
 448  * gating qual is actually constant FALSE, and that case is dealt with in
 449  * clausesel.c).  Interpolating between the two cases is silly, because
 450  * it doesn't reflect what will really happen at runtime, and besides which
 451  * in most cases we have only a very bad idea of the probability of the gating
 452  * qual being true.
 453  */
 454 static Plan *
 455 create_gating_plan(PlannerInfo *root, Plan *plan, List *quals)
 456 {
 457         List       *pseudoconstants;
 458
 459         /* Sort into desirable execution order while still in RestrictInfo form */
 460         quals = order_qual_clauses(root, quals);
 461
 462         /* Pull out any pseudoconstant quals from the RestrictInfo list */
 463         pseudoconstants = extract_actual_clauses(quals, true);
 464
 465         if (!pseudoconstants)
 466                 return plan;
 467
 468         return (Plan *) make_result(root,
 469                                                                 plan->targetlist,
 470                                                                 (Node *) pseudoconstants,
 471                                                                 plan);
 472 }
 473
 474 /*
 475  * create_join_plan
 476  *        Create a join plan for 'best_path' and (recursively) plans for its
 477  *        inner and outer paths.
 478  */
 479 static Plan *
 480 create_join_plan(PlannerInfo *root, JoinPath *best_path)
 481 {
 482         Plan       *outer_plan;
 483         Plan       *inner_plan;
 484         Plan       *plan;
 485
 486         outer_plan = create_plan(root, best_path->outerjoinpath);
 487         inner_plan = create_plan(root, best_path->innerjoinpath);
 488
 489         switch (best_path->path.pathtype)
 490         {
 491                 case T_MergeJoin:
 492                         plan = (Plan *) create_mergejoin_plan(root,
 493                                                                                                   (MergePath *) best_path,
 494                                                                                                   outer_plan,
 495                                                                                                   inner_plan);
 496                         break;
 497                 case T_HashJoin:
 498                         plan = (Plan *) create_hashjoin_plan(root,
 499                                                                                                  (HashPath *) best_path,
 500                                                                                                  outer_plan,
 501                                                                                                  inner_plan);
 502                         break;
 503                 case T_NestLoop:
 504                         plan = (Plan *) create_nestloop_plan(root,
 505                                                                                                  (NestPath *) best_path,
 506                                                                                                  outer_plan,
 507                                                                                                  inner_plan);
 508                         break;
 509                 default:
 510                         elog(ERROR, "unrecognized node type: %d",
 511                                  (int) best_path->path.pathtype);
 512                         plan = NULL;            /* keep compiler quiet */
 513                         break;
 514         }
 515
 516         /*
 517          * If there are any pseudoconstant clauses attached to this node, insert a
 518          * gating Result node that evaluates the pseudoconstants as one-time
 519          * quals.
 520          */
 521         if (root->hasPseudoConstantQuals)
 522                 plan = create_gating_plan(root, plan, best_path->joinrestrictinfo);
 523
 524 #ifdef NOT_USED
 525
 526         /*
 527          * * Expensive function pullups may have pulled local predicates * into
 528          * this path node.      Put them in the qpqual of the plan node. * JMH,
 529          * 6/15/92
 530          */
 531         if (get_loc_restrictinfo(best_path) != NIL)
 532                 set_qpqual((Plan) plan,
 533                                    list_concat(get_qpqual((Plan) plan),
 534                                            get_actual_clauses(get_loc_restrictinfo(best_path))));
 535 #endif
 536
 537         return plan;
 538 }
 539
 540 /*
 541  * create_append_plan
 542  *        Create an Append plan for 'best_path' and (recursively) plans
 543  *        for its subpaths.
 544  *
 545  *        Returns a Plan node.
 546  */
 547 static Plan *
 548 create_append_plan(PlannerInfo *root, AppendPath *best_path)
 549 {
 550         Append     *plan;
 551         List       *tlist = build_relation_tlist(best_path->path.parent);
 552         List       *subplans = NIL;
 553         ListCell   *subpaths;
 554
 555         /*
 556          * It is possible for the subplans list to contain only one entry, or even
 557          * no entries.  Handle these cases specially.
 558          *
 559          * XXX ideally, if there's just one entry, we'd not bother to generate an
 560          * Append node but just return the single child.  At the moment this does
 561          * not work because the varno of the child scan plan won't match the
 562          * parent-rel Vars it'll be asked to emit.
 563          */
 564         if (best_path->subpaths == NIL)
 565         {
 566                 /* Generate a Result plan with constant-FALSE gating qual */
 567                 return (Plan *) make_result(root,
 568                                                                         tlist,
 569                                                                         (Node *) list_make1(makeBoolConst(false,
 570                                                                                                                                           false)),
 571                                                                         NULL);
 572         }
 573
 574         /* Normal case with multiple subpaths */
 575         foreach(subpaths, best_path->subpaths)
 576         {
 577                 Path       *subpath = (Path *) lfirst(subpaths);
 578
 579                 subplans = lappend(subplans, create_plan(root, subpath));
 580         }
 581
 582         plan = make_append(subplans, tlist);
 583
 584         return (Plan *) plan;
 585 }
 586
 587 /*
 588  * create_result_plan
 589  *        Create a Result plan for 'best_path'.
 590  *        This is only used for the case of a query with an empty jointree.
 591  *
 592  *        Returns a Plan node.
 593  */
 594 static Result *
 595 create_result_plan(PlannerInfo *root, ResultPath *best_path)
 596 {
 597         List       *tlist;
 598         List       *quals;
 599
 600         /* The tlist will be installed later, since we have no RelOptInfo */
 601         Assert(best_path->path.parent == NULL);
 602         tlist = NIL;
 603
 604         /* best_path->quals is just bare clauses */
 605
 606         quals = order_qual_clauses(root, best_path->quals);
 607
 608         return make_result(root, tlist, (Node *) quals, NULL);
 609 }
 610
 611 /*
 612  * create_material_plan
 613  *        Create a Material plan for 'best_path' and (recursively) plans
 614  *        for its subpaths.
 615  *
 616  *        Returns a Plan node.
 617  */
 618 static Material *
 619 create_material_plan(PlannerInfo *root, MaterialPath *best_path)
 620 {
 621         Material   *plan;
 622         Plan       *subplan;
 623
 624         subplan = create_plan(root, best_path->subpath);
 625
 626         /* We don't want any excess columns in the materialized tuples */
 627         disuse_physical_tlist(subplan, best_path->subpath);
 628
 629         plan = make_material(subplan);
 630
 631         copy_path_costsize(&plan->plan, (Path *) best_path);
 632
 633         return plan;
 634 }
 635
 636 /*
 637  * create_unique_plan
 638  *        Create a Unique plan for 'best_path' and (recursively) plans
 639  *        for its subpaths.
 640  *
 641  *        Returns a Plan node.
 642  */
 643 static Plan *
 644 create_unique_plan(PlannerInfo *root, UniquePath *best_path)
 645 {
 646         Plan       *plan;
 647         Plan       *subplan;
 648         List       *in_operators;
 649         List       *uniq_exprs;
 650         List       *newtlist;
 651         int                     nextresno;
 652         bool            newitems;
 653         int                     numGroupCols;
 654         AttrNumber *groupColIdx;
 655         int                     groupColPos;
 656         ListCell   *l;
 657
 658         subplan = create_plan(root, best_path->subpath);
 659
 660         /* Done if we don't need to do any actual unique-ifying */
 661         if (best_path->umethod == UNIQUE_PATH_NOOP)
 662                 return subplan;
 663
 664         /*
 665          * As constructed, the subplan has a "flat" tlist containing just the Vars
 666          * needed here and at upper levels.  The values we are supposed to
 667          * unique-ify may be expressions in these variables.  We have to add any
 668          * such expressions to the subplan's tlist.
 669          *
 670          * The subplan may have a "physical" tlist if it is a simple scan plan. If
 671          * we're going to sort, this should be reduced to the regular tlist, so
 672          * that we don't sort more data than we need to.  For hashing, the tlist
 673          * should be left as-is if we don't need to add any expressions; but if we
 674          * do have to add expressions, then a projection step will be needed at
 675          * runtime anyway, so we may as well remove unneeded items. Therefore
 676          * newtlist starts from build_relation_tlist() not just a copy of the
 677          * subplan's tlist; and we don't install it into the subplan unless we are
 678          * sorting or stuff has to be added.
 679          */
 680         in_operators = best_path->in_operators;
 681         uniq_exprs = best_path->uniq_exprs;
 682
 683         /* initialize modified subplan tlist as just the "required" vars */
 684         newtlist = build_relation_tlist(best_path->path.parent);
 685         nextresno = list_length(newtlist) + 1;
 686         newitems = false;
 687
 688         foreach(l, uniq_exprs)
 689         {
 690                 Node       *uniqexpr = lfirst(l);
 691                 TargetEntry *tle;
 692
 693                 tle = tlist_member(uniqexpr, newtlist);
 694                 if (!tle)
 695                 {
 696                         tle = makeTargetEntry((Expr *) uniqexpr,
 697                                                                   nextresno,
 698                                                                   NULL,
 699                                                                   false);
 700                         newtlist = lappend(newtlist, tle);
 701                         nextresno++;
 702                         newitems = true;
 703                 }
 704         }
 705
 706         if (newitems || best_path->umethod == UNIQUE_PATH_SORT)
 707         {
 708                 /*
 709                  * If the top plan node can't do projections, we need to add a Result
 710                  * node to help it along.
 711                  */
 712                 if (!is_projection_capable_plan(subplan))
 713                         subplan = (Plan *) make_result(root, newtlist, NULL, subplan);
 714                 else
 715                         subplan->targetlist = newtlist;
 716         }
 717
 718         /*
 719          * Build control information showing which subplan output columns are to
 720          * be examined by the grouping step.  Unfortunately we can't merge this
 721          * with the previous loop, since we didn't then know which version of the
 722          * subplan tlist we'd end up using.
 723          */
 724         newtlist = subplan->targetlist;
 725         numGroupCols = list_length(uniq_exprs);
 726         groupColIdx = (AttrNumber *) palloc(numGroupCols * sizeof(AttrNumber));
 727
 728         groupColPos = 0;
 729         foreach(l, uniq_exprs)
 730         {
 731                 Node       *uniqexpr = lfirst(l);
 732                 TargetEntry *tle;
 733
 734                 tle = tlist_member(uniqexpr, newtlist);
 735                 if (!tle)                               /* shouldn't happen */
 736                         elog(ERROR, "failed to find unique expression in subplan tlist");
 737                 groupColIdx[groupColPos++] = tle->resno;
 738         }
 739
 740         if (best_path->umethod == UNIQUE_PATH_HASH)
 741         {
 742                 long            numGroups;
 743                 Oid                *groupOperators;
 744
 745                 numGroups = (long) Min(best_path->rows, (double) LONG_MAX);
 746
 747                 /*
 748                  * Get the hashable equality operators for the Agg node to use.
 749                  * Normally these are the same as the IN clause operators, but if
 750                  * those are cross-type operators then the equality operators are the
 751                  * ones for the IN clause operators' RHS datatype.
 752                  */
 753                 groupOperators = (Oid *) palloc(numGroupCols * sizeof(Oid));
 754                 groupColPos = 0;
 755                 foreach(l, in_operators)
 756                 {
 757                         Oid                     in_oper = lfirst_oid(l);
 758                         Oid                     eq_oper;
 759
 760                         if (!get_compatible_hash_operators(in_oper, NULL, &eq_oper))
 761                                 elog(ERROR, "could not find compatible hash operator for operator %u",
 762                                          in_oper);
 763                         groupOperators[groupColPos++] = eq_oper;
 764                 }
 765
 766                 /*
 767                  * Since the Agg node is going to project anyway, we can give it the
 768                  * minimum output tlist, without any stuff we might have added to the
 769                  * subplan tlist.
 770                  */
 771                 plan = (Plan *) make_agg(root,
 772                                                                  build_relation_tlist(best_path->path.parent),
 773                                                                  NIL,
 774                                                                  AGG_HASHED,
 775                                                                  numGroupCols,
 776                                                                  groupColIdx,
 777                                                                  groupOperators,
 778                                                                  numGroups,
 779                                                                  0,
 780                                                                  subplan);
 781         }
 782         else
 783         {
 784                 List       *sortList = NIL;
 785
 786                 /* Create an ORDER BY list to sort the input compatibly */
 787                 groupColPos = 0;
 788                 foreach(l, in_operators)
 789                 {
 790                         Oid                     in_oper = lfirst_oid(l);
 791                         Oid                     sortop;
 792                         TargetEntry *tle;
 793                         SortGroupClause *sortcl;
 794
 795                         sortop = get_ordering_op_for_equality_op(in_oper, false);
 796                         if (!OidIsValid(sortop))        /* shouldn't happen */
 797                                 elog(ERROR, "could not find ordering operator for equality operator %u",
 798                                          in_oper);
 799                         tle = get_tle_by_resno(subplan->targetlist,
 800                                                                    groupColIdx[groupColPos]);
 801                         Assert(tle != NULL);
 802                         sortcl = makeNode(SortGroupClause);
 803                         sortcl->tleSortGroupRef = assignSortGroupRef(tle,
 804                                                                                                                  subplan->targetlist);
 805                         sortcl->eqop = in_oper;
 806                         sortcl->sortop = sortop;
 807                         sortcl->nulls_first = false;
 808                         sortList = lappend(sortList, sortcl);
 809                         groupColPos++;
 810                 }
 811                 plan = (Plan *) make_sort_from_sortclauses(root, sortList, subplan);
 812                 plan = (Plan *) make_unique(plan, sortList);
 813         }
 814
 815         /* Adjust output size estimate (other fields should be OK already) */
 816         plan->plan_rows = best_path->rows;
 817
 818         return plan;
 819 }
 820
 821
 822 /*****************************************************************************
 823  *
 824  *      BASE-RELATION SCAN METHODS
 825  *
 826  *****************************************************************************/
 827
 828
 829 /*
 830  * create_seqscan_plan
 831  *       Returns a seqscan plan for the base relation scanned by 'best_path'
 832  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
 833  */
 834 static SeqScan *
 835 create_seqscan_plan(PlannerInfo *root, Path *best_path,
 836                                         List *tlist, List *scan_clauses)
 837 {
 838         SeqScan    *scan_plan;
 839         Index           scan_relid = best_path->parent->relid;
 840
 841         /* it should be a base rel... */
 842         Assert(scan_relid > 0);
 843         Assert(best_path->parent->rtekind == RTE_RELATION);
 844
 845         /* Sort clauses into best execution order */
 846         scan_clauses = order_qual_clauses(root, scan_clauses);
 847
 848         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
 849         scan_clauses = extract_actual_clauses(scan_clauses, false);
 850
 851         scan_plan = make_seqscan(tlist,
 852                                                          scan_clauses,
 853                                                          scan_relid);
 854
 855         copy_path_costsize(&scan_plan->plan, best_path);
 856
 857         return scan_plan;
 858 }
 859
 860 /*
 861  * create_indexscan_plan
 862  *        Returns an indexscan plan for the base relation scanned by 'best_path'
 863  *        with restriction clauses 'scan_clauses' and targetlist 'tlist'.
 864  *
 865  * The indexquals list of the path contains implicitly-ANDed qual conditions.
 866  * The list can be empty --- then no index restrictions will be applied during
 867  * the scan.
 868  */
 869 static IndexScan *
 870 create_indexscan_plan(PlannerInfo *root,
 871                                           IndexPath *best_path,
 872                                           List *tlist,
 873                                           List *scan_clauses)
 874 {
 875         List       *indexquals = best_path->indexquals;
 876         Index           baserelid = best_path->path.parent->relid;
 877         Oid                     indexoid = best_path->indexinfo->indexoid;
 878         List       *qpqual;
 879         List       *stripped_indexquals;
 880         List       *fixed_indexquals;
 881         ListCell   *l;
 882         IndexScan  *scan_plan;
 883
 884         /* it should be a base rel... */
 885         Assert(baserelid > 0);
 886         Assert(best_path->path.parent->rtekind == RTE_RELATION);
 887
 888         /*
 889          * Build "stripped" indexquals structure (no RestrictInfos) to pass to
 890          * executor as indexqualorig
 891          */
 892         stripped_indexquals = get_actual_clauses(indexquals);
 893
 894         /*
 895          * The executor needs a copy with the indexkey on the left of each clause
 896          * and with index attr numbers substituted for table ones.
 897          */
 898         fixed_indexquals = fix_indexqual_references(indexquals, best_path);
 899
 900         /*
 901          * If this is an innerjoin scan, the indexclauses will contain join
 902          * clauses that are not present in scan_clauses (since the passed-in value
 903          * is just the rel's baserestrictinfo list).  We must add these clauses to
 904          * scan_clauses to ensure they get checked.  In most cases we will remove
 905          * the join clauses again below, but if a join clause contains a special
 906          * operator, we need to make sure it gets into the scan_clauses.
 907          *
 908          * Note: pointer comparison should be enough to determine RestrictInfo
 909          * matches.
 910          */
 911         if (best_path->isjoininner)
 912                 scan_clauses = list_union_ptr(scan_clauses, best_path->indexclauses);
 913
 914         /*
 915          * The qpqual list must contain all restrictions not automatically handled
 916          * by the index.  All the predicates in the indexquals will be checked
 917          * (either by the index itself, or by nodeIndexscan.c), but if there are
 918          * any "special" operators involved then they must be included in qpqual.
 919          * The upshot is that qpqual must contain scan_clauses minus whatever
 920          * appears in indexquals.
 921          *
 922          * In normal cases simple pointer equality checks will be enough to spot
 923          * duplicate RestrictInfos, so we try that first.  In some situations
 924          * (particularly with OR'd index conditions) we may have scan_clauses that
 925          * are not equal to, but are logically implied by, the index quals; so we
 926          * also try a predicate_implied_by() check to see if we can discard quals
 927          * that way.  (predicate_implied_by assumes its first input contains only
 928          * immutable functions, so we have to check that.)
 929          *
 930          * We can also discard quals that are implied by a partial index's
 931          * predicate, but only in a plain SELECT; when scanning a target relation
 932          * of UPDATE/DELETE/SELECT FOR UPDATE, we must leave such quals in the
 933          * plan so that they'll be properly rechecked by EvalPlanQual testing.
 934          */
 935         qpqual = NIL;
 936         foreach(l, scan_clauses)
 937         {
 938                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
 939
 940                 Assert(IsA(rinfo, RestrictInfo));
 941                 if (rinfo->pseudoconstant)
 942                         continue;                       /* we may drop pseudoconstants here */
 943                 if (list_member_ptr(indexquals, rinfo))
 944                         continue;
 945                 if (!contain_mutable_functions((Node *) rinfo->clause))
 946                 {
 947                         List       *clausel = list_make1(rinfo->clause);
 948
 949                         if (predicate_implied_by(clausel, indexquals))
 950                                 continue;
 951                         if (best_path->indexinfo->indpred)
 952                         {
 953                                 if (baserelid != root->parse->resultRelation &&
 954                                         get_rowmark(root->parse, baserelid) == NULL)
 955                                         if (predicate_implied_by(clausel,
 956                                                                                          best_path->indexinfo->indpred))
 957                                                 continue;
 958                         }
 959                 }
 960                 qpqual = lappend(qpqual, rinfo);
 961         }
 962
 963         /* Sort clauses into best execution order */
 964         qpqual = order_qual_clauses(root, qpqual);
 965
 966         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
 967         qpqual = extract_actual_clauses(qpqual, false);
 968
 969         /* Finally ready to build the plan node */
 970         scan_plan = make_indexscan(tlist,
 971                                                            qpqual,
 972                                                            baserelid,
 973                                                            indexoid,
 974                                                            fixed_indexquals,
 975                                                            stripped_indexquals,
 976                                                            best_path->indexscandir);
 977
 978         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
 979         /* use the indexscan-specific rows estimate, not the parent rel's */
 980         scan_plan->scan.plan.plan_rows = best_path->rows;
 981
 982         return scan_plan;
 983 }
 984
 985 /*
 986  * create_bitmap_scan_plan
 987  *        Returns a bitmap scan plan for the base relation scanned by 'best_path'
 988  *        with restriction clauses 'scan_clauses' and targetlist 'tlist'.
 989  */
 990 static BitmapHeapScan *
 991 create_bitmap_scan_plan(PlannerInfo *root,
 992                                                 BitmapHeapPath *best_path,
 993                                                 List *tlist,
 994                                                 List *scan_clauses)
 995 {
 996         Index           baserelid = best_path->path.parent->relid;
 997         Plan       *bitmapqualplan;
 998         List       *bitmapqualorig;
 999         List       *indexquals;
1000         List       *qpqual;
1001         ListCell   *l;
1002         BitmapHeapScan *scan_plan;
1003
1004         /* it should be a base rel... */
1005         Assert(baserelid > 0);
1006         Assert(best_path->path.parent->rtekind == RTE_RELATION);
1007
1008         /* Process the bitmapqual tree into a Plan tree and qual lists */
1009         bitmapqualplan = create_bitmap_subplan(root, best_path->bitmapqual,
1010                                                                                    &bitmapqualorig, &indexquals);
1011
1012         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1013         scan_clauses = extract_actual_clauses(scan_clauses, false);
1014
1015         /*
1016          * If this is a innerjoin scan, the indexclauses will contain join clauses
1017          * that are not present in scan_clauses (since the passed-in value is just
1018          * the rel's baserestrictinfo list).  We must add these clauses to
1019          * scan_clauses to ensure they get checked.  In most cases we will remove
1020          * the join clauses again below, but if a join clause contains a special
1021          * operator, we need to make sure it gets into the scan_clauses.
1022          */
1023         if (best_path->isjoininner)
1024         {
1025                 scan_clauses = list_concat_unique(scan_clauses, bitmapqualorig);
1026         }
1027
1028         /*
1029          * The qpqual list must contain all restrictions not automatically handled
1030          * by the index.  All the predicates in the indexquals will be checked
1031          * (either by the index itself, or by nodeBitmapHeapscan.c), but if there
1032          * are any "special" operators involved then they must be added to qpqual.
1033          * The upshot is that qpqual must contain scan_clauses minus whatever
1034          * appears in indexquals.
1035          *
1036          * In normal cases simple equal() checks will be enough to spot duplicate
1037          * clauses, so we try that first.  In some situations (particularly with
1038          * OR'd index conditions) we may have scan_clauses that are not equal to,
1039          * but are logically implied by, the index quals; so we also try a
1040          * predicate_implied_by() check to see if we can discard quals that way.
1041          * (predicate_implied_by assumes its first input contains only immutable
1042          * functions, so we have to check that.)
1043          *
1044          * Unlike create_indexscan_plan(), we need take no special thought here
1045          * for partial index predicates; this is because the predicate conditions
1046          * are already listed in bitmapqualorig and indexquals.  Bitmap scans have
1047          * to do it that way because predicate conditions need to be rechecked if
1048          * the scan becomes lossy.
1049          */
1050         qpqual = NIL;
1051         foreach(l, scan_clauses)
1052         {
1053                 Node       *clause = (Node *) lfirst(l);
1054
1055                 if (list_member(indexquals, clause))
1056                         continue;
1057                 if (!contain_mutable_functions(clause))
1058                 {
1059                         List       *clausel = list_make1(clause);
1060
1061                         if (predicate_implied_by(clausel, indexquals))
1062                                 continue;
1063                 }
1064                 qpqual = lappend(qpqual, clause);
1065         }
1066
1067         /* Sort clauses into best execution order */
1068         qpqual = order_qual_clauses(root, qpqual);
1069
1070         /*
1071          * When dealing with special operators, we will at this point have
1072          * duplicate clauses in qpqual and bitmapqualorig.      We may as well drop
1073          * 'em from bitmapqualorig, since there's no point in making the tests
1074          * twice.
1075          */
1076         bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual);
1077
1078         /* Finally ready to build the plan node */
1079         scan_plan = make_bitmap_heapscan(tlist,
1080                                                                          qpqual,
1081                                                                          bitmapqualplan,
1082                                                                          bitmapqualorig,
1083                                                                          baserelid);
1084
1085         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1086         /* use the indexscan-specific rows estimate, not the parent rel's */
1087         scan_plan->scan.plan.plan_rows = best_path->rows;
1088
1089         return scan_plan;
1090 }
1091
1092 /*
1093  * Given a bitmapqual tree, generate the Plan tree that implements it
1094  *
1095  * As byproducts, we also return in *qual and *indexqual the qual lists
1096  * (in implicit-AND form, without RestrictInfos) describing the original index
1097  * conditions and the generated indexqual conditions.  (These are the same in
1098  * simple cases, but when special index operators are involved, the former
1099  * list includes the special conditions while the latter includes the actual
1100  * indexable conditions derived from them.)  Both lists include partial-index
1101  * predicates, because we have to recheck predicates as well as index
1102  * conditions if the bitmap scan becomes lossy.
1103  *
1104  * Note: if you find yourself changing this, you probably need to change
1105  * make_restrictinfo_from_bitmapqual too.
1106  */
1107 static Plan *
1108 create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
1109                                           List **qual, List **indexqual)
1110 {
1111         Plan       *plan;
1112
1113         if (IsA(bitmapqual, BitmapAndPath))
1114         {
1115                 BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
1116                 List       *subplans = NIL;
1117                 List       *subquals = NIL;
1118                 List       *subindexquals = NIL;
1119                 ListCell   *l;
1120
1121                 /*
1122                  * There may well be redundant quals among the subplans, since a
1123                  * top-level WHERE qual might have gotten used to form several
1124                  * different index quals.  We don't try exceedingly hard to eliminate
1125                  * redundancies, but we do eliminate obvious duplicates by using
1126                  * list_concat_unique.
1127                  */
1128                 foreach(l, apath->bitmapquals)
1129                 {
1130                         Plan       *subplan;
1131                         List       *subqual;
1132                         List       *subindexqual;
1133
1134                         subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
1135                                                                                         &subqual, &subindexqual);
1136                         subplans = lappend(subplans, subplan);
1137                         subquals = list_concat_unique(subquals, subqual);
1138                         subindexquals = list_concat_unique(subindexquals, subindexqual);
1139                 }
1140                 plan = (Plan *) make_bitmap_and(subplans);
1141                 plan->startup_cost = apath->path.startup_cost;
1142                 plan->total_cost = apath->path.total_cost;
1143                 plan->plan_rows =
1144                         clamp_row_est(apath->bitmapselectivity * apath->path.parent->tuples);
1145                 plan->plan_width = 0;   /* meaningless */
1146                 *qual = subquals;
1147                 *indexqual = subindexquals;
1148         }
1149         else if (IsA(bitmapqual, BitmapOrPath))
1150         {
1151                 BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
1152                 List       *subplans = NIL;
1153                 List       *subquals = NIL;
1154                 List       *subindexquals = NIL;
1155                 bool            const_true_subqual = false;
1156                 bool            const_true_subindexqual = false;
1157                 ListCell   *l;
1158
1159                 /*
1160                  * Here, we only detect qual-free subplans.  A qual-free subplan would
1161                  * cause us to generate "... OR true ..."  which we may as well reduce
1162                  * to just "true".      We do not try to eliminate redundant subclauses
1163                  * because (a) it's not as likely as in the AND case, and (b) we might
1164                  * well be working with hundreds or even thousands of OR conditions,
1165                  * perhaps from a long IN list.  The performance of list_append_unique
1166                  * would be unacceptable.
1167                  */
1168                 foreach(l, opath->bitmapquals)
1169                 {
1170                         Plan       *subplan;
1171                         List       *subqual;
1172                         List       *subindexqual;
1173
1174                         subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
1175                                                                                         &subqual, &subindexqual);
1176                         subplans = lappend(subplans, subplan);
1177                         if (subqual == NIL)
1178                                 const_true_subqual = true;
1179                         else if (!const_true_subqual)
1180                                 subquals = lappend(subquals,
1181                                                                    make_ands_explicit(subqual));
1182                         if (subindexqual == NIL)
1183                                 const_true_subindexqual = true;
1184                         else if (!const_true_subindexqual)
1185                                 subindexquals = lappend(subindexquals,
1186                                                                                 make_ands_explicit(subindexqual));
1187                 }
1188
1189                 /*
1190                  * In the presence of ScalarArrayOpExpr quals, we might have built
1191                  * BitmapOrPaths with just one subpath; don't add an OR step.
1192                  */
1193                 if (list_length(subplans) == 1)
1194                 {
1195                         plan = (Plan *) linitial(subplans);
1196                 }
1197                 else
1198                 {
1199                         plan = (Plan *) make_bitmap_or(subplans);
1200                         plan->startup_cost = opath->path.startup_cost;
1201                         plan->total_cost = opath->path.total_cost;
1202                         plan->plan_rows =
1203                                 clamp_row_est(opath->bitmapselectivity * opath->path.parent->tuples);
1204                         plan->plan_width = 0;           /* meaningless */
1205                 }
1206
1207                 /*
1208                  * If there were constant-TRUE subquals, the OR reduces to constant
1209                  * TRUE.  Also, avoid generating one-element ORs, which could happen
1210                  * due to redundancy elimination or ScalarArrayOpExpr quals.
1211                  */
1212                 if (const_true_subqual)
1213                         *qual = NIL;
1214                 else if (list_length(subquals) <= 1)
1215                         *qual = subquals;
1216                 else
1217                         *qual = list_make1(make_orclause(subquals));
1218                 if (const_true_subindexqual)
1219                         *indexqual = NIL;
1220                 else if (list_length(subindexquals) <= 1)
1221                         *indexqual = subindexquals;
1222                 else
1223                         *indexqual = list_make1(make_orclause(subindexquals));
1224         }
1225         else if (IsA(bitmapqual, IndexPath))
1226         {
1227                 IndexPath  *ipath = (IndexPath *) bitmapqual;
1228                 IndexScan  *iscan;
1229                 ListCell   *l;
1230
1231                 /* Use the regular indexscan plan build machinery... */
1232                 iscan = create_indexscan_plan(root, ipath, NIL, NIL);
1233                 /* then convert to a bitmap indexscan */
1234                 plan = (Plan *) make_bitmap_indexscan(iscan->scan.scanrelid,
1235                                                                                           iscan->indexid,
1236                                                                                           iscan->indexqual,
1237                                                                                           iscan->indexqualorig);
1238                 plan->startup_cost = 0.0;
1239                 plan->total_cost = ipath->indextotalcost;
1240                 plan->plan_rows =
1241                         clamp_row_est(ipath->indexselectivity * ipath->path.parent->tuples);
1242                 plan->plan_width = 0;   /* meaningless */
1243                 *qual = get_actual_clauses(ipath->indexclauses);
1244                 *indexqual = get_actual_clauses(ipath->indexquals);
1245                 foreach(l, ipath->indexinfo->indpred)
1246                 {
1247                         Expr       *pred = (Expr *) lfirst(l);
1248
1249                         /*
1250                          * We know that the index predicate must have been implied by the
1251                          * query condition as a whole, but it may or may not be implied by
1252                          * the conditions that got pushed into the bitmapqual.  Avoid
1253                          * generating redundant conditions.
1254                          */
1255                         if (!predicate_implied_by(list_make1(pred), ipath->indexclauses))
1256                         {
1257                                 *qual = lappend(*qual, pred);
1258                                 *indexqual = lappend(*indexqual, pred);
1259                         }
1260                 }
1261         }
1262         else
1263         {
1264                 elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
1265                 plan = NULL;                    /* keep compiler quiet */
1266         }
1267
1268         return plan;
1269 }
1270
1271 /*
1272  * create_tidscan_plan
1273  *       Returns a tidscan plan for the base relation scanned by 'best_path'
1274  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1275  */
1276 static TidScan *
1277 create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
1278                                         List *tlist, List *scan_clauses)
1279 {
1280         TidScan    *scan_plan;
1281         Index           scan_relid = best_path->path.parent->relid;
1282         List       *ortidquals;
1283
1284         /* it should be a base rel... */
1285         Assert(scan_relid > 0);
1286         Assert(best_path->path.parent->rtekind == RTE_RELATION);
1287
1288         /* Sort clauses into best execution order */
1289         scan_clauses = order_qual_clauses(root, scan_clauses);
1290
1291         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1292         scan_clauses = extract_actual_clauses(scan_clauses, false);
1293
1294         /*
1295          * Remove any clauses that are TID quals.  This is a bit tricky since the
1296          * tidquals list has implicit OR semantics.
1297          */
1298         ortidquals = best_path->tidquals;
1299         if (list_length(ortidquals) > 1)
1300                 ortidquals = list_make1(make_orclause(ortidquals));
1301         scan_clauses = list_difference(scan_clauses, ortidquals);
1302
1303         scan_plan = make_tidscan(tlist,
1304                                                          scan_clauses,
1305                                                          scan_relid,
1306                                                          best_path->tidquals);
1307
1308         copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
1309
1310         return scan_plan;
1311 }
1312
1313 /*
1314  * create_subqueryscan_plan
1315  *       Returns a subqueryscan plan for the base relation scanned by 'best_path'
1316  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1317  */
1318 static SubqueryScan *
1319 create_subqueryscan_plan(PlannerInfo *root, Path *best_path,
1320                                                  List *tlist, List *scan_clauses)
1321 {
1322         SubqueryScan *scan_plan;
1323         Index           scan_relid = best_path->parent->relid;
1324
1325         /* it should be a subquery base rel... */
1326         Assert(scan_relid > 0);
1327         Assert(best_path->parent->rtekind == RTE_SUBQUERY);
1328
1329         /* Sort clauses into best execution order */
1330         scan_clauses = order_qual_clauses(root, scan_clauses);
1331
1332         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1333         scan_clauses = extract_actual_clauses(scan_clauses, false);
1334
1335         scan_plan = make_subqueryscan(tlist,
1336                                                                   scan_clauses,
1337                                                                   scan_relid,
1338                                                                   best_path->parent->subplan,
1339                                                                   best_path->parent->subrtable,
1340                                                                   best_path->parent->subrowmark);
1341
1342         copy_path_costsize(&scan_plan->scan.plan, best_path);
1343
1344         return scan_plan;
1345 }
1346
1347 /*
1348  * create_functionscan_plan
1349  *       Returns a functionscan plan for the base relation scanned by 'best_path'
1350  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1351  */
1352 static FunctionScan *
1353 create_functionscan_plan(PlannerInfo *root, Path *best_path,
1354                                                  List *tlist, List *scan_clauses)
1355 {
1356         FunctionScan *scan_plan;
1357         Index           scan_relid = best_path->parent->relid;
1358         RangeTblEntry *rte;
1359
1360         /* it should be a function base rel... */
1361         Assert(scan_relid > 0);
1362         rte = planner_rt_fetch(scan_relid, root);
1363         Assert(rte->rtekind == RTE_FUNCTION);
1364
1365         /* Sort clauses into best execution order */
1366         scan_clauses = order_qual_clauses(root, scan_clauses);
1367
1368         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1369         scan_clauses = extract_actual_clauses(scan_clauses, false);
1370
1371         scan_plan = make_functionscan(tlist, scan_clauses, scan_relid,
1372                                                                   rte->funcexpr,
1373                                                                   rte->eref->colnames,
1374                                                                   rte->funccoltypes,
1375                                                                   rte->funccoltypmods);
1376
1377         copy_path_costsize(&scan_plan->scan.plan, best_path);
1378
1379         return scan_plan;
1380 }
1381
1382 /*
1383  * create_valuesscan_plan
1384  *       Returns a valuesscan plan for the base relation scanned by 'best_path'
1385  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1386  */
1387 static ValuesScan *
1388 create_valuesscan_plan(PlannerInfo *root, Path *best_path,
1389                                            List *tlist, List *scan_clauses)
1390 {
1391         ValuesScan *scan_plan;
1392         Index           scan_relid = best_path->parent->relid;
1393         RangeTblEntry *rte;
1394
1395         /* it should be a values base rel... */
1396         Assert(scan_relid > 0);
1397         rte = planner_rt_fetch(scan_relid, root);
1398         Assert(rte->rtekind == RTE_VALUES);
1399
1400         /* Sort clauses into best execution order */
1401         scan_clauses = order_qual_clauses(root, scan_clauses);
1402
1403         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1404         scan_clauses = extract_actual_clauses(scan_clauses, false);
1405
1406         scan_plan = make_valuesscan(tlist, scan_clauses, scan_relid,
1407                                                                 rte->values_lists);
1408
1409         copy_path_costsize(&scan_plan->scan.plan, best_path);
1410
1411         return scan_plan;
1412 }
1413
1414 /*
1415  * create_ctescan_plan
1416  *       Returns a ctescan plan for the base relation scanned by 'best_path'
1417  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1418  */
1419 static CteScan *
1420 create_ctescan_plan(PlannerInfo *root, Path *best_path,
1421                                         List *tlist, List *scan_clauses)
1422 {
1423         CteScan    *scan_plan;
1424         Index           scan_relid = best_path->parent->relid;
1425         RangeTblEntry *rte;
1426         SubPlan    *ctesplan = NULL;
1427         int                     plan_id;
1428         int                     cte_param_id;
1429         PlannerInfo *cteroot;
1430         Index           levelsup;
1431         int                     ndx;
1432         ListCell   *lc;
1433
1434         Assert(scan_relid > 0);
1435         rte = planner_rt_fetch(scan_relid, root);
1436         Assert(rte->rtekind == RTE_CTE);
1437         Assert(!rte->self_reference);
1438
1439         /*
1440          * Find the referenced CTE, and locate the SubPlan previously made for it.
1441          */
1442         levelsup = rte->ctelevelsup;
1443         cteroot = root;
1444         while (levelsup-- > 0)
1445         {
1446                 cteroot = cteroot->parent_root;
1447                 if (!cteroot)                   /* shouldn't happen */
1448                         elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1449         }
1450
1451         /*
1452          * Note: cte_plan_ids can be shorter than cteList, if we are still working
1453          * on planning the CTEs (ie, this is a side-reference from another CTE).
1454          * So we mustn't use forboth here.
1455          */
1456         ndx = 0;
1457         foreach(lc, cteroot->parse->cteList)
1458         {
1459                 CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
1460
1461                 if (strcmp(cte->ctename, rte->ctename) == 0)
1462                         break;
1463                 ndx++;
1464         }
1465         if (lc == NULL)                         /* shouldn't happen */
1466                 elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
1467         if (ndx >= list_length(cteroot->cte_plan_ids))
1468                 elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
1469         plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
1470         Assert(plan_id > 0);
1471         foreach(lc, cteroot->init_plans)
1472         {
1473                 ctesplan = (SubPlan *) lfirst(lc);
1474                 if (ctesplan->plan_id == plan_id)
1475                         break;
1476         }
1477         if (lc == NULL)                         /* shouldn't happen */
1478                 elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
1479
1480         /*
1481          * We need the CTE param ID, which is the sole member of the SubPlan's
1482          * setParam list.
1483          */
1484         cte_param_id = linitial_int(ctesplan->setParam);
1485
1486         /* Sort clauses into best execution order */
1487         scan_clauses = order_qual_clauses(root, scan_clauses);
1488
1489         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1490         scan_clauses = extract_actual_clauses(scan_clauses, false);
1491
1492         scan_plan = make_ctescan(tlist, scan_clauses, scan_relid,
1493                                                          plan_id, cte_param_id);
1494
1495         copy_path_costsize(&scan_plan->scan.plan, best_path);
1496
1497         return scan_plan;
1498 }
1499
1500 /*
1501  * create_worktablescan_plan
1502  *       Returns a worktablescan plan for the base relation scanned by 'best_path'
1503  *       with restriction clauses 'scan_clauses' and targetlist 'tlist'.
1504  */
1505 static WorkTableScan *
1506 create_worktablescan_plan(PlannerInfo *root, Path *best_path,
1507                                                   List *tlist, List *scan_clauses)
1508 {
1509         WorkTableScan *scan_plan;
1510         Index           scan_relid = best_path->parent->relid;
1511         RangeTblEntry *rte;
1512         Index           levelsup;
1513         PlannerInfo *cteroot;
1514
1515         Assert(scan_relid > 0);
1516         rte = planner_rt_fetch(scan_relid, root);
1517         Assert(rte->rtekind == RTE_CTE);
1518         Assert(rte->self_reference);
1519
1520         /*
1521          * We need to find the worktable param ID, which is in the plan level
1522          * that's processing the recursive UNION, which is one level *below* where
1523          * the CTE comes from.
1524          */
1525         levelsup = rte->ctelevelsup;
1526         if (levelsup == 0)                      /* shouldn't happen */
1527                 elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1528         levelsup--;
1529         cteroot = root;
1530         while (levelsup-- > 0)
1531         {
1532                 cteroot = cteroot->parent_root;
1533                 if (!cteroot)                   /* shouldn't happen */
1534                         elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
1535         }
1536         if (cteroot->wt_param_id < 0)           /* shouldn't happen */
1537                 elog(ERROR, "could not find param ID for CTE \"%s\"", rte->ctename);
1538
1539         /* Sort clauses into best execution order */
1540         scan_clauses = order_qual_clauses(root, scan_clauses);
1541
1542         /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
1543         scan_clauses = extract_actual_clauses(scan_clauses, false);
1544
1545         scan_plan = make_worktablescan(tlist, scan_clauses, scan_relid,
1546                                                                    cteroot->wt_param_id);
1547
1548         copy_path_costsize(&scan_plan->scan.plan, best_path);
1549
1550         return scan_plan;
1551 }
1552
1553
1554 /*****************************************************************************
1555  *
1556  *      JOIN METHODS
1557  *
1558  *****************************************************************************/
1559
1560 static NestLoop *
1561 create_nestloop_plan(PlannerInfo *root,
1562                                          NestPath *best_path,
1563                                          Plan *outer_plan,
1564                                          Plan *inner_plan)
1565 {
1566         List       *tlist = build_relation_tlist(best_path->path.parent);
1567         List       *joinrestrictclauses = best_path->joinrestrictinfo;
1568         List       *joinclauses;
1569         List       *otherclauses;
1570         NestLoop   *join_plan;
1571
1572         /*
1573          * If the inner path is a nestloop inner indexscan, it might be using some
1574          * of the join quals as index quals, in which case we don't have to check
1575          * them again at the join node.  Remove any join quals that are redundant.
1576          */
1577         joinrestrictclauses =
1578                 select_nonredundant_join_clauses(root,
1579                                                                                  joinrestrictclauses,
1580                                                                                  best_path->innerjoinpath);
1581
1582         /* Sort join qual clauses into best execution order */
1583         joinrestrictclauses = order_qual_clauses(root, joinrestrictclauses);
1584
1585         /* Get the join qual clauses (in plain expression form) */
1586         /* Any pseudoconstant clauses are ignored here */
1587         if (IS_OUTER_JOIN(best_path->jointype))
1588         {
1589                 extract_actual_join_clauses(joinrestrictclauses,
1590                                                                         &joinclauses, &otherclauses);
1591         }
1592         else
1593         {
1594                 /* We can treat all clauses alike for an inner join */
1595                 joinclauses = extract_actual_clauses(joinrestrictclauses, false);
1596                 otherclauses = NIL;
1597         }
1598
1599         join_plan = make_nestloop(tlist,
1600                                                           joinclauses,
1601                                                           otherclauses,
1602                                                           outer_plan,
1603                                                           inner_plan,
1604                                                           best_path->jointype);
1605
1606         copy_path_costsize(&join_plan->join.plan, &best_path->path);
1607
1608         return join_plan;
1609 }
1610
1611 static MergeJoin *
1612 create_mergejoin_plan(PlannerInfo *root,
1613                                           MergePath *best_path,
1614                                           Plan *outer_plan,
1615                                           Plan *inner_plan)
1616 {
1617         List       *tlist = build_relation_tlist(best_path->jpath.path.parent);
1618         List       *joinclauses;
1619         List       *otherclauses;
1620         List       *mergeclauses;
1621         List       *outerpathkeys;
1622         List       *innerpathkeys;
1623         int                     nClauses;
1624         Oid                *mergefamilies;
1625         int                *mergestrategies;
1626         bool       *mergenullsfirst;
1627         MergeJoin  *join_plan;
1628         int                     i;
1629         ListCell   *lc;
1630         ListCell   *lop;
1631         ListCell   *lip;
1632
1633         /* Sort join qual clauses into best execution order */
1634         /* NB: do NOT reorder the mergeclauses */
1635         joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
1636
1637         /* Get the join qual clauses (in plain expression form) */
1638         /* Any pseudoconstant clauses are ignored here */
1639         if (IS_OUTER_JOIN(best_path->jpath.jointype))
1640         {
1641                 extract_actual_join_clauses(joinclauses,
1642                                                                         &joinclauses, &otherclauses);
1643         }
1644         else
1645         {
1646                 /* We can treat all clauses alike for an inner join */
1647                 joinclauses = extract_actual_clauses(joinclauses, false);
1648                 otherclauses = NIL;
1649         }
1650
1651         /*
1652          * Remove the mergeclauses from the list of join qual clauses, leaving the
1653          * list of quals that must be checked as qpquals.
1654          */
1655         mergeclauses = get_actual_clauses(best_path->path_mergeclauses);
1656         joinclauses = list_difference(joinclauses, mergeclauses);
1657
1658         /*
1659          * Rearrange mergeclauses, if needed, so that the outer variable is always
1660          * on the left; mark the mergeclause restrictinfos with correct
1661          * outer_is_left status.
1662          */
1663         mergeclauses = get_switched_clauses(best_path->path_mergeclauses,
1664                                                          best_path->jpath.outerjoinpath->parent->relids);
1665
1666         /*
1667          * Create explicit sort nodes for the outer and inner join paths if
1668          * necessary.  The sort cost was already accounted for in the path. Make
1669          * sure there are no excess columns in the inputs if sorting.
1670          */
1671         if (best_path->outersortkeys)
1672         {
1673                 disuse_physical_tlist(outer_plan, best_path->jpath.outerjoinpath);
1674                 outer_plan = (Plan *)
1675                         make_sort_from_pathkeys(root,
1676                                                                         outer_plan,
1677                                                                         best_path->outersortkeys,
1678                                                                         -1.0);
1679                 outerpathkeys = best_path->outersortkeys;
1680         }
1681         else
1682                 outerpathkeys = best_path->jpath.outerjoinpath->pathkeys;
1683
1684         if (best_path->innersortkeys)
1685         {
1686                 disuse_physical_tlist(inner_plan, best_path->jpath.innerjoinpath);
1687                 inner_plan = (Plan *)
1688                         make_sort_from_pathkeys(root,
1689                                                                         inner_plan,
1690                                                                         best_path->innersortkeys,
1691                                                                         -1.0);
1692                 innerpathkeys = best_path->innersortkeys;
1693         }
1694         else
1695                 innerpathkeys = best_path->jpath.innerjoinpath->pathkeys;
1696
1697         /*
1698          * If inner plan is a sort that is expected to spill to disk, add a
1699          * materialize node to shield it from the need to handle mark/restore.
1700          * This will allow it to perform the last merge pass on-the-fly, while in
1701          * most cases not requiring the materialize to spill to disk.
1702          *
1703          * XXX really, Sort oughta do this for itself, probably, to avoid the
1704          * overhead of a separate plan node.
1705          */
1706         if (IsA(inner_plan, Sort) &&
1707                 sort_exceeds_work_mem((Sort *) inner_plan))
1708         {
1709                 Plan       *matplan = (Plan *) make_material(inner_plan);
1710
1711                 /*
1712                  * We assume the materialize will not spill to disk, and therefore
1713                  * charge just cpu_tuple_cost per tuple.  (Keep this estimate in sync
1714                  * with similar ones in cost_mergejoin and create_mergejoin_path.)
1715                  */
1716                 copy_plan_costsize(matplan, inner_plan);
1717                 matplan->total_cost += cpu_tuple_cost * matplan->plan_rows;
1718
1719                 inner_plan = matplan;
1720         }
1721
1722         /*
1723          * Compute the opfamily/strategy/nullsfirst arrays needed by the executor.
1724          * The information is in the pathkeys for the two inputs, but we need to
1725          * be careful about the possibility of mergeclauses sharing a pathkey
1726          * (compare find_mergeclauses_for_pathkeys()).
1727          */
1728         nClauses = list_length(mergeclauses);
1729         Assert(nClauses == list_length(best_path->path_mergeclauses));
1730         mergefamilies = (Oid *) palloc(nClauses * sizeof(Oid));
1731         mergestrategies = (int *) palloc(nClauses * sizeof(int));
1732         mergenullsfirst = (bool *) palloc(nClauses * sizeof(bool));
1733
1734         lop = list_head(outerpathkeys);
1735         lip = list_head(innerpathkeys);
1736         i = 0;
1737         foreach(lc, best_path->path_mergeclauses)
1738         {
1739                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1740                 EquivalenceClass *oeclass;
1741                 EquivalenceClass *ieclass;
1742                 PathKey    *opathkey;
1743                 PathKey    *ipathkey;
1744                 EquivalenceClass *opeclass;
1745                 EquivalenceClass *ipeclass;
1746                 ListCell   *l2;
1747
1748                 /* fetch outer/inner eclass from mergeclause */
1749                 Assert(IsA(rinfo, RestrictInfo));
1750                 if (rinfo->outer_is_left)
1751                 {
1752                         oeclass = rinfo->left_ec;
1753                         ieclass = rinfo->right_ec;
1754                 }
1755                 else
1756                 {
1757                         oeclass = rinfo->right_ec;
1758                         ieclass = rinfo->left_ec;
1759                 }
1760                 Assert(oeclass != NULL);
1761                 Assert(ieclass != NULL);
1762
1763                 /*
1764                  * For debugging purposes, we check that the eclasses match the
1765                  * paths' pathkeys.  In typical cases the merge clauses are one-to-one
1766                  * with the pathkeys, but when dealing with partially redundant query
1767                  * conditions, we might have clauses that re-reference earlier path
1768                  * keys.  The case that we need to reject is where a pathkey is
1769                  * entirely skipped over.
1770                  *
1771                  * lop and lip reference the first as-yet-unused pathkey elements;
1772                  * it's okay to match them, or any element before them.  If they're
1773                  * NULL then we have found all pathkey elements to be used.
1774                  */
1775                 if (lop)
1776                 {
1777                         opathkey = (PathKey *) lfirst(lop);
1778                         opeclass = opathkey->pk_eclass;
1779                         if (oeclass == opeclass)
1780                         {
1781                                 /* fast path for typical case */
1782                                 lop = lnext(lop);
1783                         }
1784                         else
1785                         {
1786                                 /* redundant clauses ... must match something before lop */
1787                                 foreach(l2, outerpathkeys)
1788                                 {
1789                                         if (l2 == lop)
1790                                                 break;
1791                                         opathkey = (PathKey *) lfirst(l2);
1792                                         opeclass = opathkey->pk_eclass;
1793                                         if (oeclass == opeclass)
1794                                                 break;
1795                                 }
1796                                 if (oeclass != opeclass)
1797                                         elog(ERROR, "outer pathkeys do not match mergeclauses");
1798                         }
1799                 }
1800                 else
1801                 {
1802                         /* redundant clauses ... must match some already-used pathkey */
1803                         opathkey = NULL;
1804                         opeclass = NULL;
1805                         foreach(l2, outerpathkeys)
1806                         {
1807                                 opathkey = (PathKey *) lfirst(l2);
1808                                 opeclass = opathkey->pk_eclass;
1809                                 if (oeclass == opeclass)
1810                                         break;
1811                         }
1812                         if (l2 == NULL)
1813                                 elog(ERROR, "outer pathkeys do not match mergeclauses");
1814                 }
1815
1816                 if (lip)
1817                 {
1818                         ipathkey = (PathKey *) lfirst(lip);
1819                         ipeclass = ipathkey->pk_eclass;
1820                         if (ieclass == ipeclass)
1821                         {
1822                                 /* fast path for typical case */
1823                                 lip = lnext(lip);
1824                         }
1825                         else
1826                         {
1827                                 /* redundant clauses ... must match something before lip */
1828                                 foreach(l2, innerpathkeys)
1829                                 {
1830                                         if (l2 == lip)
1831                                                 break;
1832                                         ipathkey = (PathKey *) lfirst(l2);
1833                                         ipeclass = ipathkey->pk_eclass;
1834                                         if (ieclass == ipeclass)
1835                                                 break;
1836                                 }
1837                                 if (ieclass != ipeclass)
1838                                         elog(ERROR, "inner pathkeys do not match mergeclauses");
1839                         }
1840                 }
1841                 else
1842                 {
1843                         /* redundant clauses ... must match some already-used pathkey */
1844                         ipathkey = NULL;
1845                         ipeclass = NULL;
1846                         foreach(l2, innerpathkeys)
1847                         {
1848                                 ipathkey = (PathKey *) lfirst(l2);
1849                                 ipeclass = ipathkey->pk_eclass;
1850                                 if (ieclass == ipeclass)
1851                                         break;
1852                         }
1853                         if (l2 == NULL)
1854                                 elog(ERROR, "inner pathkeys do not match mergeclauses");
1855                 }
1856
1857                 /* pathkeys should match each other too (more debugging) */
1858                 if (opathkey->pk_opfamily != ipathkey->pk_opfamily ||
1859                         opathkey->pk_strategy != ipathkey->pk_strategy ||
1860                         opathkey->pk_nulls_first != ipathkey->pk_nulls_first)
1861                         elog(ERROR, "left and right pathkeys do not match in mergejoin");
1862
1863                 /* OK, save info for executor */
1864                 mergefamilies[i] = opathkey->pk_opfamily;
1865                 mergestrategies[i] = opathkey->pk_strategy;
1866                 mergenullsfirst[i] = opathkey->pk_nulls_first;
1867                 i++;
1868         }
1869
1870         /*
1871          * Note: it is not an error if we have additional pathkey elements
1872          * (i.e., lop or lip isn't NULL here).  The input paths might be
1873          * better-sorted than we need for the current mergejoin.
1874          */
1875
1876         /*
1877          * Now we can build the mergejoin node.
1878          */
1879         join_plan = make_mergejoin(tlist,
1880                                                            joinclauses,
1881                                                            otherclauses,
1882                                                            mergeclauses,
1883                                                            mergefamilies,
1884                                                            mergestrategies,
1885                                                            mergenullsfirst,
1886                                                            outer_plan,
1887                                                            inner_plan,
1888                                                            best_path->jpath.jointype);
1889
1890         copy_path_costsize(&join_plan->join.plan, &best_path->jpath.path);
1891
1892         return join_plan;
1893 }
1894
1895 static HashJoin *
1896 create_hashjoin_plan(PlannerInfo *root,
1897                                          HashPath *best_path,
1898                                          Plan *outer_plan,
1899                                          Plan *inner_plan)
1900 {
1901         List       *tlist = build_relation_tlist(best_path->jpath.path.parent);
1902         List       *joinclauses;
1903         List       *otherclauses;
1904         List       *hashclauses;
1905         Oid                     skewTable = InvalidOid;
1906         AttrNumber      skewColumn = InvalidAttrNumber;
1907         Oid                     skewColType = InvalidOid;
1908         int32           skewColTypmod = -1;
1909         HashJoin   *join_plan;
1910         Hash       *hash_plan;
1911
1912         /* Sort join qual clauses into best execution order */
1913         joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
1914         /* There's no point in sorting the hash clauses ... */
1915
1916         /* Get the join qual clauses (in plain expression form) */
1917         /* Any pseudoconstant clauses are ignored here */
1918         if (IS_OUTER_JOIN(best_path->jpath.jointype))
1919         {
1920                 extract_actual_join_clauses(joinclauses,
1921                                                                         &joinclauses, &otherclauses);
1922         }
1923         else
1924         {
1925                 /* We can treat all clauses alike for an inner join */
1926                 joinclauses = extract_actual_clauses(joinclauses, false);
1927                 otherclauses = NIL;
1928         }
1929
1930         /*
1931          * Remove the hashclauses from the list of join qual clauses, leaving the
1932          * list of quals that must be checked as qpquals.
1933          */
1934         hashclauses = get_actual_clauses(best_path->path_hashclauses);
1935         joinclauses = list_difference(joinclauses, hashclauses);
1936
1937         /*
1938          * Rearrange hashclauses, if needed, so that the outer variable is always
1939          * on the left.
1940          */
1941         hashclauses = get_switched_clauses(best_path->path_hashclauses,
1942                                                          best_path->jpath.outerjoinpath->parent->relids);
1943
1944         /* We don't want any excess columns in the hashed tuples */
1945         disuse_physical_tlist(inner_plan, best_path->jpath.innerjoinpath);
1946
1947         /* If we expect batching, suppress excess columns in outer tuples too */
1948         if (best_path->num_batches > 1)
1949                 disuse_physical_tlist(outer_plan, best_path->jpath.outerjoinpath);
1950
1951         /*
1952          * If there is a single join clause and we can identify the outer variable
1953          * as a simple column reference, supply its identity for possible use in
1954          * skew optimization.  (Note: in principle we could do skew optimization
1955          * with multiple join clauses, but we'd have to be able to determine the
1956          * most common combinations of outer values, which we don't currently have
1957          * enough stats for.)
1958          */
1959         if (list_length(hashclauses) == 1)
1960         {
1961                 OpExpr     *clause = (OpExpr *) linitial(hashclauses);
1962                 Node       *node;
1963
1964                 Assert(is_opclause(clause));
1965                 node = (Node *) linitial(clause->args);
1966                 if (IsA(node, RelabelType))
1967                         node = (Node *) ((RelabelType *) node)->arg;
1968                 if (IsA(node, Var))
1969                 {
1970                         Var                *var = (Var *) node;
1971                         RangeTblEntry *rte;
1972
1973                         rte = root->simple_rte_array[var->varno];
1974                         if (rte->rtekind == RTE_RELATION)
1975                         {
1976                                 skewTable = rte->relid;
1977                                 skewColumn = var->varattno;
1978                                 skewColType = var->vartype;
1979                                 skewColTypmod = var->vartypmod;
1980                         }
1981                 }
1982         }
1983
1984         /*
1985          * Build the hash node and hash join node.
1986          */
1987         hash_plan = make_hash(inner_plan,
1988                                                   skewTable,
1989                                                   skewColumn,
1990                                                   skewColType,
1991                                                   skewColTypmod);
1992         join_plan = make_hashjoin(tlist,
1993                                                           joinclauses,
1994                                                           otherclauses,
1995                                                           hashclauses,
1996                                                           outer_plan,
1997                                                           (Plan *) hash_plan,
1998                                                           best_path->jpath.jointype);
1999
2000         copy_path_costsize(&join_plan->join.plan, &best_path->jpath.path);
2001
2002         return join_plan;
2003 }
2004
2005
2006 /*****************************************************************************
2007  *
2008  *      SUPPORTING ROUTINES
2009  *
2010  *****************************************************************************/
2011
2012 /*
2013  * fix_indexqual_references
2014  *        Adjust indexqual clauses to the form the executor's indexqual
2015  *        machinery needs.
2016  *
2017  * We have three tasks here:
2018  *      * Remove RestrictInfo nodes from the input clauses.
2019  *      * Index keys must be represented by Var nodes with varattno set to the
2020  *        index's attribute number, not the attribute number in the original rel.
2021  *      * If the index key is on the right, commute the clause to put it on the
2022  *        left.
2023  *
2024  * The result is a modified copy of the indexquals list --- the
2025  * original is not changed.  Note also that the copy shares no substructure
2026  * with the original; this is needed in case there is a subplan in it (we need
2027  * two separate copies of the subplan tree, or things will go awry).
2028  */
2029 static List *
2030 fix_indexqual_references(List *indexquals, IndexPath *index_path)
2031 {
2032         IndexOptInfo *index = index_path->indexinfo;
2033         List       *fixed_indexquals;
2034         ListCell   *l;
2035
2036         fixed_indexquals = NIL;
2037
2038         /*
2039          * For each qual clause, commute if needed to put the indexkey operand on
2040          * the left, and then fix its varattno.  (We do not need to change the
2041          * other side of the clause.)
2042          */
2043         foreach(l, indexquals)
2044         {
2045                 RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
2046                 Expr       *clause;
2047
2048                 Assert(IsA(rinfo, RestrictInfo));
2049
2050                 /*
2051                  * Make a copy that will become the fixed clause.
2052                  *
2053                  * We used to try to do a shallow copy here, but that fails if there
2054                  * is a subplan in the arguments of the opclause.  So just do a full
2055                  * copy.
2056                  */
2057                 clause = (Expr *) copyObject((Node *) rinfo->clause);
2058
2059                 if (IsA(clause, OpExpr))
2060                 {
2061                         OpExpr     *op = (OpExpr *) clause;
2062
2063                         if (list_length(op->args) != 2)
2064                                 elog(ERROR, "indexqual clause is not binary opclause");
2065
2066                         /*
2067                          * Check to see if the indexkey is on the right; if so, commute
2068                          * the clause. The indexkey should be the side that refers to
2069                          * (only) the base relation.
2070                          */
2071                         if (!bms_equal(rinfo->left_relids, index->rel->relids))
2072                                 CommuteOpExpr(op);
2073
2074                         /*
2075                          * Now, determine which index attribute this is and change the
2076                          * indexkey operand as needed.
2077                          */
2078                         linitial(op->args) = fix_indexqual_operand(linitial(op->args),
2079                                                                                                            index);
2080                 }
2081                 else if (IsA(clause, RowCompareExpr))
2082                 {
2083                         RowCompareExpr *rc = (RowCompareExpr *) clause;
2084                         ListCell   *lc;
2085
2086                         /*
2087                          * Check to see if the indexkey is on the right; if so, commute
2088                          * the clause. The indexkey should be the side that refers to
2089                          * (only) the base relation.
2090                          */
2091                         if (!bms_overlap(pull_varnos(linitial(rc->largs)),
2092                                                          index->rel->relids))
2093                                 CommuteRowCompareExpr(rc);
2094
2095                         /*
2096                          * For each column in the row comparison, determine which index
2097                          * attribute this is and change the indexkey operand as needed.
2098                          */
2099                         foreach(lc, rc->largs)
2100                         {
2101                                 lfirst(lc) = fix_indexqual_operand(lfirst(lc),
2102                                                                                                    index);
2103                         }
2104                 }
2105                 else if (IsA(clause, ScalarArrayOpExpr))
2106                 {
2107                         ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
2108
2109                         /* Never need to commute... */
2110
2111                         /*
2112                          * Determine which index attribute this is and change the indexkey
2113                          * operand as needed.
2114                          */
2115                         linitial(saop->args) = fix_indexqual_operand(linitial(saop->args),
2116                                                                                                                  index);
2117                 }
2118                 else if (IsA(clause, NullTest))
2119                 {
2120                         NullTest   *nt = (NullTest *) clause;
2121
2122                         Assert(nt->nulltesttype == IS_NULL);
2123                         nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg,
2124                                                                                                          index);
2125                 }
2126                 else
2127                         elog(ERROR, "unsupported indexqual type: %d",
2128                                  (int) nodeTag(clause));
2129
2130                 fixed_indexquals = lappend(fixed_indexquals, clause);
2131         }
2132
2133         return fixed_indexquals;
2134 }
2135
2136 static Node *
2137 fix_indexqual_operand(Node *node, IndexOptInfo *index)
2138 {
2139         /*
2140          * We represent index keys by Var nodes having the varno of the base table
2141          * but varattno equal to the index's attribute number (index column
2142          * position).  This is a bit hokey ... would be cleaner to use a
2143          * special-purpose node type that could not be mistaken for a regular Var.
2144          * But it will do for now.
2145          */
2146         Var                *result;
2147         int                     pos;
2148         ListCell   *indexpr_item;
2149
2150         /*
2151          * Remove any binary-compatible relabeling of the indexkey
2152          */
2153         if (IsA(node, RelabelType))
2154                 node = (Node *) ((RelabelType *) node)->arg;
2155
2156         if (IsA(node, Var) &&
2157                 ((Var *) node)->varno == index->rel->relid)
2158         {
2159                 /* Try to match against simple index columns */
2160                 int                     varatt = ((Var *) node)->varattno;
2161
2162                 if (varatt != 0)
2163                 {
2164                         for (pos = 0; pos < index->ncolumns; pos++)
2165                         {
2166                                 if (index->indexkeys[pos] == varatt)
2167                                 {
2168                                         result = (Var *) copyObject(node);
2169                                         result->varattno = pos + 1;
2170                                         return (Node *) result;
2171                                 }
2172                         }
2173                 }
2174         }
2175
2176         /* Try to match against index expressions */
2177         indexpr_item = list_head(index->indexprs);
2178         for (pos = 0; pos < index->ncolumns; pos++)
2179         {
2180                 if (index->indexkeys[pos] == 0)
2181                 {
2182                         Node       *indexkey;
2183
2184                         if (indexpr_item == NULL)
2185                                 elog(ERROR, "too few entries in indexprs list");
2186                         indexkey = (Node *) lfirst(indexpr_item);
2187                         if (indexkey && IsA(indexkey, RelabelType))
2188                                 indexkey = (Node *) ((RelabelType *) indexkey)->arg;
2189                         if (equal(node, indexkey))
2190                         {
2191                                 /* Found a match */
2192                                 result = makeVar(index->rel->relid, pos + 1,
2193                                                                  exprType(lfirst(indexpr_item)), -1,
2194                                                                  0);
2195                                 return (Node *) result;
2196                         }
2197                         indexpr_item = lnext(indexpr_item);
2198                 }
2199         }
2200
2201         /* Ooops... */
2202         elog(ERROR, "node is not an index attribute");
2203         return NULL;                            /* keep compiler quiet */
2204 }
2205
2206 /*
2207  * get_switched_clauses
2208  *        Given a list of merge or hash joinclauses (as RestrictInfo nodes),
2209  *        extract the bare clauses, and rearrange the elements within the
2210  *        clauses, if needed, so the outer join variable is on the left and
2211  *        the inner is on the right.  The original clause data structure is not
2212  *        touched; a modified list is returned.  We do, however, set the transient
2213  *        outer_is_left field in each RestrictInfo to show which side was which.
2214  */
2215 static List *
2216 get_switched_clauses(List *clauses, Relids outerrelids)
2217 {
2218         List       *t_list = NIL;
2219         ListCell   *l;
2220
2221         foreach(l, clauses)
2222         {
2223                 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(l);
2224                 OpExpr     *clause = (OpExpr *) restrictinfo->clause;
2225
2226                 Assert(is_opclause(clause));
2227                 if (bms_is_subset(restrictinfo->right_relids, outerrelids))
2228                 {
2229                         /*
2230                          * Duplicate just enough of the structure to allow commuting the
2231                          * clause without changing the original list.  Could use
2232                          * copyObject, but a complete deep copy is overkill.
2233                          */
2234                         OpExpr     *temp = makeNode(OpExpr);
2235
2236                         temp->opno = clause->opno;
2237                         temp->opfuncid = InvalidOid;
2238                         temp->opresulttype = clause->opresulttype;
2239                         temp->opretset = clause->opretset;
2240                         temp->args = list_copy(clause->args);
2241                         temp->location = clause->location;
2242                         /* Commute it --- note this modifies the temp node in-place. */
2243                         CommuteOpExpr(temp);
2244                         t_list = lappend(t_list, temp);
2245                         restrictinfo->outer_is_left = false;
2246                 }
2247                 else
2248                 {
2249                         Assert(bms_is_subset(restrictinfo->left_relids, outerrelids));
2250                         t_list = lappend(t_list, clause);
2251                         restrictinfo->outer_is_left = true;
2252                 }
2253         }
2254         return t_list;
2255 }
2256
2257 /*
2258  * order_qual_clauses
2259  *              Given a list of qual clauses that will all be evaluated at the same
2260  *              plan node, sort the list into the order we want to check the quals
2261  *              in at runtime.
2262  *
2263  * Ideally the order should be driven by a combination of execution cost and
2264  * selectivity, but it's not immediately clear how to account for both,
2265  * and given the uncertainty of the estimates the reliability of the decisions
2266  * would be doubtful anyway.  So we just order by estimated per-tuple cost,
2267  * being careful not to change the order when (as is often the case) the
2268  * estimates are identical.
2269  *
2270  * Although this will work on either bare clauses or RestrictInfos, it's
2271  * much faster to apply it to RestrictInfos, since it can re-use cost
2272  * information that is cached in RestrictInfos.
2273  *
2274  * Note: some callers pass lists that contain entries that will later be
2275  * removed; this is the easiest way to let this routine see RestrictInfos
2276  * instead of bare clauses.  It's OK because we only sort by cost, but
2277  * a cost/selectivity combination would likely do the wrong thing.
2278  */
2279 static List *
2280 order_qual_clauses(PlannerInfo *root, List *clauses)
2281 {
2282         typedef struct
2283         {
2284                 Node       *clause;
2285                 Cost            cost;
2286         } QualItem;
2287         int                     nitems = list_length(clauses);
2288         QualItem   *items;
2289         ListCell   *lc;
2290         int                     i;
2291         List       *result;
2292
2293         /* No need to work hard for 0 or 1 clause */
2294         if (nitems <= 1)
2295                 return clauses;
2296
2297         /*
2298          * Collect the items and costs into an array.  This is to avoid repeated
2299          * cost_qual_eval work if the inputs aren't RestrictInfos.
2300          */
2301         items = (QualItem *) palloc(nitems * sizeof(QualItem));
2302         i = 0;
2303         foreach(lc, clauses)
2304         {
2305                 Node       *clause = (Node *) lfirst(lc);
2306                 QualCost        qcost;
2307
2308                 cost_qual_eval_node(&qcost, clause, root);
2309                 items[i].clause = clause;
2310                 items[i].cost = qcost.per_tuple;
2311                 i++;
2312         }
2313
2314         /*
2315          * Sort.  We don't use qsort() because it's not guaranteed stable for
2316          * equal keys.  The expected number of entries is small enough that a
2317          * simple insertion sort should be good enough.
2318          */
2319         for (i = 1; i < nitems; i++)
2320         {
2321                 QualItem        newitem = items[i];
2322                 int                     j;
2323
2324                 /* insert newitem into the already-sorted subarray */
2325                 for (j = i; j > 0; j--)
2326                 {
2327                         if (newitem.cost >= items[j - 1].cost)
2328                                 break;
2329                         items[j] = items[j - 1];
2330                 }
2331                 items[j] = newitem;
2332         }
2333
2334         /* Convert back to a list */
2335         result = NIL;
2336         for (i = 0; i < nitems; i++)
2337                 result = lappend(result, items[i].clause);
2338
2339         return result;
2340 }
2341
2342 /*
2343  * Copy cost and size info from a Path node to the Plan node created from it.
2344  * The executor won't use this info, but it's needed by EXPLAIN.
2345  */
2346 static void
2347 copy_path_costsize(Plan *dest, Path *src)
2348 {
2349         if (src)
2350         {
2351                 dest->startup_cost = src->startup_cost;
2352                 dest->total_cost = src->total_cost;
2353                 dest->plan_rows = src->parent->rows;
2354                 dest->plan_width = src->parent->width;
2355         }
2356         else
2357         {
2358                 dest->startup_cost = 0;
2359                 dest->total_cost = 0;
2360                 dest->plan_rows = 0;
2361                 dest->plan_width = 0;
2362         }
2363 }
2364
2365 /*
2366  * Copy cost and size info from a lower plan node to an inserted node.
2367  * This is not critical, since the decisions have already been made,
2368  * but it helps produce more reasonable-looking EXPLAIN output.
2369  * (Some callers alter the info after copying it.)
2370  */
2371 static void
2372 copy_plan_costsize(Plan *dest, Plan *src)
2373 {
2374         if (src)
2375         {
2376                 dest->startup_cost = src->startup_cost;
2377                 dest->total_cost = src->total_cost;
2378                 dest->plan_rows = src->plan_rows;
2379                 dest->plan_width = src->plan_width;
2380         }
2381         else
2382         {
2383                 dest->startup_cost = 0;
2384                 dest->total_cost = 0;
2385                 dest->plan_rows = 0;
2386                 dest->plan_width = 0;
2387         }
2388 }
2389
2390
2391 /*****************************************************************************
2392  *
2393  *      PLAN NODE BUILDING ROUTINES
2394  *
2395  * Some of these are exported because they are called to build plan nodes
2396  * in contexts where we're not deriving the plan node from a path node.
2397  *
2398  *****************************************************************************/
2399
2400 static SeqScan *
2401 make_seqscan(List *qptlist,
2402                          List *qpqual,
2403                          Index scanrelid)
2404 {
2405         SeqScan    *node = makeNode(SeqScan);
2406         Plan       *plan = &node->plan;
2407
2408         /* cost should be inserted by caller */
2409         plan->targetlist = qptlist;
2410         plan->qual = qpqual;
2411         plan->lefttree = NULL;
2412         plan->righttree = NULL;
2413         node->scanrelid = scanrelid;
2414
2415         return node;
2416 }
2417
2418 static IndexScan *
2419 make_indexscan(List *qptlist,
2420                            List *qpqual,
2421                            Index scanrelid,
2422                            Oid indexid,
2423                            List *indexqual,
2424                            List *indexqualorig,
2425                            ScanDirection indexscandir)
2426 {
2427         IndexScan  *node = makeNode(IndexScan);
2428         Plan       *plan = &node->scan.plan;
2429
2430         /* cost should be inserted by caller */
2431         plan->targetlist = qptlist;
2432         plan->qual = qpqual;
2433         plan->lefttree = NULL;
2434         plan->righttree = NULL;
2435         node->scan.scanrelid = scanrelid;
2436         node->indexid = indexid;
2437         node->indexqual = indexqual;
2438         node->indexqualorig = indexqualorig;
2439         node->indexorderdir = indexscandir;
2440
2441         return node;
2442 }
2443
2444 static BitmapIndexScan *
2445 make_bitmap_indexscan(Index scanrelid,
2446                                           Oid indexid,
2447                                           List *indexqual,
2448                                           List *indexqualorig)
2449 {
2450         BitmapIndexScan *node = makeNode(BitmapIndexScan);
2451         Plan       *plan = &node->scan.plan;
2452
2453         /* cost should be inserted by caller */
2454         plan->targetlist = NIL;         /* not used */
2455         plan->qual = NIL;                       /* not used */
2456         plan->lefttree = NULL;
2457         plan->righttree = NULL;
2458         node->scan.scanrelid = scanrelid;
2459         node->indexid = indexid;
2460         node->indexqual = indexqual;
2461         node->indexqualorig = indexqualorig;
2462
2463         return node;
2464 }
2465
2466 static BitmapHeapScan *
2467 make_bitmap_heapscan(List *qptlist,
2468                                          List *qpqual,
2469                                          Plan *lefttree,
2470                                          List *bitmapqualorig,
2471                                          Index scanrelid)
2472 {
2473         BitmapHeapScan *node = makeNode(BitmapHeapScan);
2474         Plan       *plan = &node->scan.plan;
2475
2476         /* cost should be inserted by caller */
2477         plan->targetlist = qptlist;
2478         plan->qual = qpqual;
2479         plan->lefttree = lefttree;
2480         plan->righttree = NULL;
2481         node->scan.scanrelid = scanrelid;
2482         node->bitmapqualorig = bitmapqualorig;
2483
2484         return node;
2485 }
2486
2487 static TidScan *
2488 make_tidscan(List *qptlist,
2489                          List *qpqual,
2490                          Index scanrelid,
2491                          List *tidquals)
2492 {
2493         TidScan    *node = makeNode(TidScan);
2494         Plan       *plan = &node->scan.plan;
2495
2496         /* cost should be inserted by caller */
2497         plan->targetlist = qptlist;
2498         plan->qual = qpqual;
2499         plan->lefttree = NULL;
2500         plan->righttree = NULL;
2501         node->scan.scanrelid = scanrelid;
2502         node->tidquals = tidquals;
2503
2504         return node;
2505 }
2506
2507 SubqueryScan *
2508 make_subqueryscan(List *qptlist,
2509                                   List *qpqual,
2510                                   Index scanrelid,
2511                                   Plan *subplan,
2512                                   List *subrtable,
2513                                   List *subrowmark)
2514 {
2515         SubqueryScan *node = makeNode(SubqueryScan);
2516         Plan       *plan = &node->scan.plan;
2517
2518         /*
2519          * Cost is figured here for the convenience of prepunion.c.  Note this is
2520          * only correct for the case where qpqual is empty; otherwise caller
2521          * should overwrite cost with a better estimate.
2522          */
2523         copy_plan_costsize(plan, subplan);
2524         plan->total_cost += cpu_tuple_cost * subplan->plan_rows;
2525
2526         plan->targetlist = qptlist;
2527         plan->qual = qpqual;
2528         plan->lefttree = NULL;
2529         plan->righttree = NULL;
2530         node->scan.scanrelid = scanrelid;
2531         node->subplan = subplan;
2532         node->subrtable = subrtable;
2533         node->subrowmark = subrowmark;
2534
2535         return node;
2536 }
2537
2538 static FunctionScan *
2539 make_functionscan(List *qptlist,
2540                                   List *qpqual,
2541                                   Index scanrelid,
2542                                   Node *funcexpr,
2543                                   List *funccolnames,
2544                                   List *funccoltypes,
2545                                   List *funccoltypmods)
2546 {
2547         FunctionScan *node = makeNode(FunctionScan);
2548         Plan       *plan = &node->scan.plan;
2549
2550         /* cost should be inserted by caller */
2551         plan->targetlist = qptlist;
2552         plan->qual = qpqual;
2553         plan->lefttree = NULL;
2554         plan->righttree = NULL;
2555         node->scan.scanrelid = scanrelid;
2556         node->funcexpr = funcexpr;
2557         node->funccolnames = funccolnames;
2558         node->funccoltypes = funccoltypes;
2559         node->funccoltypmods = funccoltypmods;
2560
2561         return node;
2562 }
2563
2564 static ValuesScan *
2565 make_valuesscan(List *qptlist,
2566                                 List *qpqual,
2567                                 Index scanrelid,
2568                                 List *values_lists)
2569 {
2570         ValuesScan *node = makeNode(ValuesScan);
2571         Plan       *plan = &node->scan.plan;
2572
2573         /* cost should be inserted by caller */
2574         plan->targetlist = qptlist;
2575         plan->qual = qpqual;
2576         plan->lefttree = NULL;
2577         plan->righttree = NULL;
2578         node->scan.scanrelid = scanrelid;
2579         node->values_lists = values_lists;
2580
2581         return node;
2582 }
2583
2584 static CteScan *
2585 make_ctescan(List *qptlist,
2586                          List *qpqual,
2587                          Index scanrelid,
2588                          int ctePlanId,
2589                          int cteParam)
2590 {
2591         CteScan    *node = makeNode(CteScan);
2592         Plan       *plan = &node->scan.plan;
2593
2594         /* cost should be inserted by caller */
2595         plan->targetlist = qptlist;
2596         plan->qual = qpqual;
2597         plan->lefttree = NULL;
2598         plan->righttree = NULL;
2599         node->scan.scanrelid = scanrelid;
2600         node->ctePlanId = ctePlanId;
2601         node->cteParam = cteParam;
2602
2603         return node;
2604 }
2605
2606 static WorkTableScan *
2607 make_worktablescan(List *qptlist,
2608                                    List *qpqual,
2609                                    Index scanrelid,
2610                                    int wtParam)
2611 {
2612         WorkTableScan *node = makeNode(WorkTableScan);
2613         Plan       *plan = &node->scan.plan;
2614
2615         /* cost should be inserted by caller */
2616         plan->targetlist = qptlist;
2617         plan->qual = qpqual;
2618         plan->lefttree = NULL;
2619         plan->righttree = NULL;
2620         node->scan.scanrelid = scanrelid;
2621         node->wtParam = wtParam;
2622
2623         return node;
2624 }
2625
2626 Append *
2627 make_append(List *appendplans, List *tlist)
2628 {
2629         Append     *node = makeNode(Append);
2630         Plan       *plan = &node->plan;
2631         double          total_size;
2632         ListCell   *subnode;
2633
2634         /*
2635          * Compute cost as sum of subplan costs.  We charge nothing extra for the
2636          * Append itself, which perhaps is too optimistic, but since it doesn't do
2637          * any selection or projection, it is a pretty cheap node.
2638          */
2639         plan->startup_cost = 0;
2640         plan->total_cost = 0;
2641         plan->plan_rows = 0;
2642         total_size = 0;
2643         foreach(subnode, appendplans)
2644         {
2645                 Plan       *subplan = (Plan *) lfirst(subnode);
2646
2647                 if (subnode == list_head(appendplans))  /* first node? */
2648                         plan->startup_cost = subplan->startup_cost;
2649                 plan->total_cost += subplan->total_cost;
2650                 plan->plan_rows += subplan->plan_rows;
2651                 total_size += subplan->plan_width * subplan->plan_rows;
2652         }
2653         if (plan->plan_rows > 0)
2654                 plan->plan_width = rint(total_size / plan->plan_rows);
2655         else
2656                 plan->plan_width = 0;
2657
2658         plan->targetlist = tlist;
2659         plan->qual = NIL;
2660         plan->lefttree = NULL;
2661         plan->righttree = NULL;
2662         node->appendplans = appendplans;
2663
2664         return node;
2665 }
2666
2667 RecursiveUnion *
2668 make_recursive_union(List *tlist,
2669                                          Plan *lefttree,
2670                                          Plan *righttree,
2671                                          int wtParam,
2672                                          List *distinctList,
2673                                          long numGroups)
2674 {
2675         RecursiveUnion *node = makeNode(RecursiveUnion);
2676         Plan       *plan = &node->plan;
2677         int                     numCols = list_length(distinctList);
2678
2679         cost_recursive_union(plan, lefttree, righttree);
2680
2681         plan->targetlist = tlist;
2682         plan->qual = NIL;
2683         plan->lefttree = lefttree;
2684         plan->righttree = righttree;
2685         node->wtParam = wtParam;
2686
2687         /*
2688          * convert SortGroupClause list into arrays of attr indexes and equality
2689          * operators, as wanted by executor
2690          */
2691         node->numCols = numCols;
2692         if (numCols > 0)
2693         {
2694                 int                     keyno = 0;
2695                 AttrNumber *dupColIdx;
2696                 Oid                *dupOperators;
2697                 ListCell   *slitem;
2698
2699                 dupColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
2700                 dupOperators = (Oid *) palloc(sizeof(Oid) * numCols);
2701
2702                 foreach(slitem, distinctList)
2703                 {
2704                         SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
2705                         TargetEntry *tle = get_sortgroupclause_tle(sortcl,
2706                                                                                                            plan->targetlist);
2707
2708                         dupColIdx[keyno] = tle->resno;
2709                         dupOperators[keyno] = sortcl->eqop;
2710                         Assert(OidIsValid(dupOperators[keyno]));
2711                         keyno++;
2712                 }
2713                 node->dupColIdx = dupColIdx;
2714                 node->dupOperators = dupOperators;
2715         }
2716         node->numGroups = numGroups;
2717
2718         return node;
2719 }
2720
2721 static BitmapAnd *
2722 make_bitmap_and(List *bitmapplans)
2723 {
2724         BitmapAnd  *node = makeNode(BitmapAnd);
2725         Plan       *plan = &node->plan;
2726
2727         /* cost should be inserted by caller */
2728         plan->targetlist = NIL;
2729         plan->qual = NIL;
2730         plan->lefttree = NULL;
2731         plan->righttree = NULL;
2732         node->bitmapplans = bitmapplans;
2733
2734         return node;
2735 }
2736
2737 static BitmapOr *
2738 make_bitmap_or(List *bitmapplans)
2739 {
2740         BitmapOr   *node = makeNode(BitmapOr);
2741         Plan       *plan = &node->plan;
2742
2743         /* cost should be inserted by caller */
2744         plan->targetlist = NIL;
2745         plan->qual = NIL;
2746         plan->lefttree = NULL;
2747         plan->righttree = NULL;
2748         node->bitmapplans = bitmapplans;
2749
2750         return node;
2751 }
2752
2753 static NestLoop *
2754 make_nestloop(List *tlist,
2755                           List *joinclauses,
2756                           List *otherclauses,
2757                           Plan *lefttree,
2758                           Plan *righttree,
2759                           JoinType jointype)
2760 {
2761         NestLoop   *node = makeNode(NestLoop);
2762         Plan       *plan = &node->join.plan;
2763
2764         /* cost should be inserted by caller */
2765         plan->targetlist = tlist;
2766         plan->qual = otherclauses;
2767         plan->lefttree = lefttree;
2768         plan->righttree = righttree;
2769         node->join.jointype = jointype;
2770         node->join.joinqual = joinclauses;
2771
2772         return node;
2773 }
2774
2775 static HashJoin *
2776 make_hashjoin(List *tlist,
2777                           List *joinclauses,
2778                           List *otherclauses,
2779                           List *hashclauses,
2780                           Plan *lefttree,
2781                           Plan *righttree,
2782                           JoinType jointype)
2783 {
2784         HashJoin   *node = makeNode(HashJoin);
2785         Plan       *plan = &node->join.plan;
2786
2787         /* cost should be inserted by caller */
2788         plan->targetlist = tlist;
2789         plan->qual = otherclauses;
2790         plan->lefttree = lefttree;
2791         plan->righttree = righttree;
2792         node->hashclauses = hashclauses;
2793         node->join.jointype = jointype;
2794         node->join.joinqual = joinclauses;
2795
2796         return node;
2797 }
2798
2799 static Hash *
2800 make_hash(Plan *lefttree,
2801                   Oid skewTable,
2802                   AttrNumber skewColumn,
2803                   Oid skewColType,
2804                   int32 skewColTypmod)
2805 {
2806         Hash       *node = makeNode(Hash);
2807         Plan       *plan = &node->plan;
2808
2809         copy_plan_costsize(plan, lefttree);
2810
2811         /*
2812          * For plausibility, make startup & total costs equal total cost of input
2813          * plan; this only affects EXPLAIN display not decisions.
2814          */
2815         plan->startup_cost = plan->total_cost;
2816         plan->targetlist = lefttree->targetlist;
2817         plan->qual = NIL;
2818         plan->lefttree = lefttree;
2819         plan->righttree = NULL;
2820
2821         node->skewTable = skewTable;
2822         node->skewColumn = skewColumn;
2823         node->skewColType = skewColType;
2824         node->skewColTypmod = skewColTypmod;
2825
2826         return node;
2827 }
2828
2829 static MergeJoin *
2830 make_mergejoin(List *tlist,
2831                            List *joinclauses,
2832                            List *otherclauses,
2833                            List *mergeclauses,
2834                            Oid *mergefamilies,
2835                            int *mergestrategies,
2836                            bool *mergenullsfirst,
2837                            Plan *lefttree,
2838                            Plan *righttree,
2839                            JoinType jointype)
2840 {
2841         MergeJoin  *node = makeNode(MergeJoin);
2842         Plan       *plan = &node->join.plan;
2843
2844         /* cost should be inserted by caller */
2845         plan->targetlist = tlist;
2846         plan->qual = otherclauses;
2847         plan->lefttree = lefttree;
2848         plan->righttree = righttree;
2849         node->mergeclauses = mergeclauses;
2850         node->mergeFamilies = mergefamilies;
2851         node->mergeStrategies = mergestrategies;
2852         node->mergeNullsFirst = mergenullsfirst;
2853         node->join.jointype = jointype;
2854         node->join.joinqual = joinclauses;
2855
2856         return node;
2857 }
2858
2859 /*
2860  * make_sort --- basic routine to build a Sort plan node
2861  *
2862  * Caller must have built the sortColIdx, sortOperators, and nullsFirst
2863  * arrays already.      limit_tuples is as for cost_sort (in particular, pass
2864  * -1 if no limit)
2865  */
2866 static Sort *
2867 make_sort(PlannerInfo *root, Plan *lefttree, int numCols,
2868                   AttrNumber *sortColIdx, Oid *sortOperators, bool *nullsFirst,
2869                   double limit_tuples)
2870 {
2871         Sort       *node = makeNode(Sort);
2872         Plan       *plan = &node->plan;
2873         Path            sort_path;              /* dummy for result of cost_sort */
2874
2875         copy_plan_costsize(plan, lefttree); /* only care about copying size */
2876         cost_sort(&sort_path, root, NIL,
2877                           lefttree->total_cost,
2878                           lefttree->plan_rows,
2879                           lefttree->plan_width,
2880                           limit_tuples);
2881         plan->startup_cost = sort_path.startup_cost;
2882         plan->total_cost = sort_path.total_cost;
2883         plan->targetlist = lefttree->targetlist;
2884         plan->qual = NIL;
2885         plan->lefttree = lefttree;
2886         plan->righttree = NULL;
2887         node->numCols = numCols;
2888         node->sortColIdx = sortColIdx;
2889         node->sortOperators = sortOperators;
2890         node->nullsFirst = nullsFirst;
2891
2892         return node;
2893 }
2894
2895 /*
2896  * add_sort_column --- utility subroutine for building sort info arrays
2897  *
2898  * We need this routine because the same column might be selected more than
2899  * once as a sort key column; if so, the extra mentions are redundant.
2900  *
2901  * Caller is assumed to have allocated the arrays large enough for the
2902  * max possible number of columns.      Return value is the new column count.
2903  */
2904 static int
2905 add_sort_column(AttrNumber colIdx, Oid sortOp, bool nulls_first,
2906                                 int numCols, AttrNumber *sortColIdx,
2907                                 Oid *sortOperators, bool *nullsFirst)
2908 {
2909         int                     i;
2910
2911         Assert(OidIsValid(sortOp));
2912
2913         for (i = 0; i < numCols; i++)
2914         {
2915                 /*
2916                  * Note: we check sortOp because it's conceivable that "ORDER BY foo
2917                  * USING <, foo USING <<<" is not redundant, if <<< distinguishes
2918                  * values that < considers equal.  We need not check nulls_first
2919                  * however because a lower-order column with the same sortop but
2920                  * opposite nulls direction is redundant.
2921                  */
2922                 if (sortColIdx[i] == colIdx &&
2923                         sortOperators[numCols] == sortOp)
2924                 {
2925                         /* Already sorting by this col, so extra sort key is useless */
2926                         return numCols;
2927                 }
2928         }
2929
2930         /* Add the column */
2931         sortColIdx[numCols] = colIdx;
2932         sortOperators[numCols] = sortOp;
2933         nullsFirst[numCols] = nulls_first;
2934         return numCols + 1;
2935 }
2936
2937 /*
2938  * make_sort_from_pathkeys
2939  *        Create sort plan to sort according to given pathkeys
2940  *
2941  *        'lefttree' is the node which yields input tuples
2942  *        'pathkeys' is the list of pathkeys by which the result is to be sorted
2943  *        'limit_tuples' is the bound on the number of output tuples;
2944  *                              -1 if no bound
2945  *
2946  * We must convert the pathkey information into arrays of sort key column
2947  * numbers and sort operator OIDs.
2948  *
2949  * If the pathkeys include expressions that aren't simple Vars, we will
2950  * usually need to add resjunk items to the input plan's targetlist to
2951  * compute these expressions (since the Sort node itself won't do it).
2952  * If the input plan type isn't one that can do projections, this means
2953  * adding a Result node just to do the projection.
2954  */
2955 Sort *
2956 make_sort_from_pathkeys(PlannerInfo *root, Plan *lefttree, List *pathkeys,
2957                                                 double limit_tuples)
2958 {
2959         List       *tlist = lefttree->targetlist;
2960         ListCell   *i;
2961         int                     numsortkeys;
2962         AttrNumber *sortColIdx;
2963         Oid                *sortOperators;
2964         bool       *nullsFirst;
2965
2966         /*
2967          * We will need at most list_length(pathkeys) sort columns; possibly less
2968          */
2969         numsortkeys = list_length(pathkeys);
2970         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
2971         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
2972         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
2973
2974         numsortkeys = 0;
2975
2976         foreach(i, pathkeys)
2977         {
2978                 PathKey    *pathkey = (PathKey *) lfirst(i);
2979                 EquivalenceClass *ec = pathkey->pk_eclass;
2980                 TargetEntry *tle = NULL;
2981                 Oid                     pk_datatype = InvalidOid;
2982                 Oid                     sortop;
2983                 ListCell   *j;
2984
2985                 if (ec->ec_has_volatile)
2986                 {
2987                         /*
2988                          * If the pathkey's EquivalenceClass is volatile, then it must
2989                          * have come from an ORDER BY clause, and we have to match it to
2990                          * that same targetlist entry.
2991                          */
2992                         if (ec->ec_sortref == 0)        /* can't happen */
2993                                 elog(ERROR, "volatile EquivalenceClass has no sortref");
2994                         tle = get_sortgroupref_tle(ec->ec_sortref, tlist);
2995                         Assert(tle);
2996                         Assert(list_length(ec->ec_members) == 1);
2997                         pk_datatype = ((EquivalenceMember *) linitial(ec->ec_members))->em_datatype;
2998                 }
2999                 else
3000                 {
3001                         /*
3002                          * Otherwise, we can sort by any non-constant expression listed in
3003                          * the pathkey's EquivalenceClass.  For now, we take the first one
3004                          * that corresponds to an available item in the tlist.  If there
3005                          * isn't any, use the first one that is an expression in the
3006                          * input's vars.  (The non-const restriction only matters if the
3007                          * EC is below_outer_join; but if it isn't, it won't contain
3008                          * consts anyway, else we'd have discarded the pathkey as
3009                          * redundant.)
3010                          *
3011                          * XXX if we have a choice, is there any way of figuring out which
3012                          * might be cheapest to execute?  (For example, int4lt is likely
3013                          * much cheaper to execute than numericlt, but both might appear
3014                          * in the same equivalence class...)  Not clear that we ever will
3015                          * have an interesting choice in practice, so it may not matter.
3016                          */
3017                         foreach(j, ec->ec_members)
3018                         {
3019                                 EquivalenceMember *em = (EquivalenceMember *) lfirst(j);
3020
3021                                 if (em->em_is_const || em->em_is_child)
3022                                         continue;
3023
3024                                 tle = tlist_member((Node *) em->em_expr, tlist);
3025                                 if (tle)
3026                                 {
3027                                         pk_datatype = em->em_datatype;
3028                                         break;          /* found expr already in tlist */
3029                                 }
3030
3031                                 /*
3032                                  * We can also use it if the pathkey expression is a relabel
3033                                  * of the tlist entry, or vice versa.  This is needed for
3034                                  * binary-compatible cases (cf. make_pathkey_from_sortinfo).
3035                                  * We prefer an exact match, though, so we do the basic search
3036                                  * first.
3037                                  */
3038                                 tle = tlist_member_ignore_relabel((Node *) em->em_expr, tlist);
3039                                 if (tle)
3040                                 {
3041                                         pk_datatype = em->em_datatype;
3042                                         break;          /* found expr already in tlist */
3043                                 }
3044                         }
3045
3046                         if (!tle)
3047                         {
3048                                 /* No matching tlist item; look for a computable expression */
3049                                 Expr       *sortexpr = NULL;
3050
3051                                 foreach(j, ec->ec_members)
3052                                 {
3053                                         EquivalenceMember *em = (EquivalenceMember *) lfirst(j);
3054                                         List       *exprvars;
3055                                         ListCell   *k;
3056
3057                                         if (em->em_is_const || em->em_is_child)
3058                                                 continue;
3059                                         sortexpr = em->em_expr;
3060                                         exprvars = pull_var_clause((Node *) sortexpr,
3061                                                                                            PVC_INCLUDE_PLACEHOLDERS);
3062                                         foreach(k, exprvars)
3063                                         {
3064                                                 if (!tlist_member_ignore_relabel(lfirst(k), tlist))
3065                                                         break;
3066                                         }
3067                                         list_free(exprvars);
3068                                         if (!k)
3069                                         {
3070                                                 pk_datatype = em->em_datatype;
3071                                                 break;  /* found usable expression */
3072                                         }
3073                                 }
3074                                 if (!j)
3075                                         elog(ERROR, "could not find pathkey item to sort");
3076
3077                                 /*
3078                                  * Do we need to insert a Result node?
3079                                  */
3080                                 if (!is_projection_capable_plan(lefttree))
3081                                 {
3082                                         /* copy needed so we don't modify input's tlist below */
3083                                         tlist = copyObject(tlist);
3084                                         lefttree = (Plan *) make_result(root, tlist, NULL,
3085                                                                                                         lefttree);
3086                                 }
3087
3088                                 /*
3089                                  * Add resjunk entry to input's tlist
3090                                  */
3091                                 tle = makeTargetEntry(sortexpr,
3092                                                                           list_length(tlist) + 1,
3093                                                                           NULL,
3094                                                                           true);
3095                                 tlist = lappend(tlist, tle);
3096                                 lefttree->targetlist = tlist;   /* just in case NIL before */
3097                         }
3098                 }
3099
3100                 /*
3101                  * Look up the correct sort operator from the PathKey's slightly
3102                  * abstracted representation.
3103                  */
3104                 sortop = get_opfamily_member(pathkey->pk_opfamily,
3105                                                                          pk_datatype,
3106                                                                          pk_datatype,
3107                                                                          pathkey->pk_strategy);
3108                 if (!OidIsValid(sortop))        /* should not happen */
3109                         elog(ERROR, "could not find member %d(%u,%u) of opfamily %u",
3110                                  pathkey->pk_strategy, pk_datatype, pk_datatype,
3111                                  pathkey->pk_opfamily);
3112
3113                 /*
3114                  * The column might already be selected as a sort key, if the pathkeys
3115                  * contain duplicate entries.  (This can happen in scenarios where
3116                  * multiple mergejoinable clauses mention the same var, for example.)
3117                  * So enter it only once in the sort arrays.
3118                  */
3119                 numsortkeys = add_sort_column(tle->resno,
3120                                                                           sortop,
3121                                                                           pathkey->pk_nulls_first,
3122                                                                           numsortkeys,
3123                                                                           sortColIdx, sortOperators, nullsFirst);
3124         }
3125
3126         Assert(numsortkeys > 0);
3127
3128         return make_sort(root, lefttree, numsortkeys,
3129                                          sortColIdx, sortOperators, nullsFirst, limit_tuples);
3130 }
3131
3132 /*
3133  * make_sort_from_sortclauses
3134  *        Create sort plan to sort according to given sortclauses
3135  *
3136  *        'sortcls' is a list of SortGroupClauses
3137  *        'lefttree' is the node which yields input tuples
3138  */
3139 Sort *
3140 make_sort_from_sortclauses(PlannerInfo *root, List *sortcls, Plan *lefttree)
3141 {
3142         List       *sub_tlist = lefttree->targetlist;
3143         ListCell   *l;
3144         int                     numsortkeys;
3145         AttrNumber *sortColIdx;
3146         Oid                *sortOperators;
3147         bool       *nullsFirst;
3148
3149         /*
3150          * We will need at most list_length(sortcls) sort columns; possibly less
3151          */
3152         numsortkeys = list_length(sortcls);
3153         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
3154         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
3155         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
3156
3157         numsortkeys = 0;
3158
3159         foreach(l, sortcls)
3160         {
3161                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(l);
3162                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, sub_tlist);
3163
3164                 /*
3165                  * Check for the possibility of duplicate order-by clauses --- the
3166                  * parser should have removed 'em, but no point in sorting
3167                  * redundantly.
3168                  */
3169                 numsortkeys = add_sort_column(tle->resno, sortcl->sortop,
3170                                                                           sortcl->nulls_first,
3171                                                                           numsortkeys,
3172                                                                           sortColIdx, sortOperators, nullsFirst);
3173         }
3174
3175         Assert(numsortkeys > 0);
3176
3177         return make_sort(root, lefttree, numsortkeys,
3178                                          sortColIdx, sortOperators, nullsFirst, -1.0);
3179 }
3180
3181 /*
3182  * make_sort_from_groupcols
3183  *        Create sort plan to sort based on grouping columns
3184  *
3185  * 'groupcls' is the list of SortGroupClauses
3186  * 'grpColIdx' gives the column numbers to use
3187  *
3188  * This might look like it could be merged with make_sort_from_sortclauses,
3189  * but presently we *must* use the grpColIdx[] array to locate sort columns,
3190  * because the child plan's tlist is not marked with ressortgroupref info
3191  * appropriate to the grouping node.  So, only the sort ordering info
3192  * is used from the SortGroupClause entries.
3193  */
3194 Sort *
3195 make_sort_from_groupcols(PlannerInfo *root,
3196                                                  List *groupcls,
3197                                                  AttrNumber *grpColIdx,
3198                                                  Plan *lefttree)
3199 {
3200         List       *sub_tlist = lefttree->targetlist;
3201         int                     grpno = 0;
3202         ListCell   *l;
3203         int                     numsortkeys;
3204         AttrNumber *sortColIdx;
3205         Oid                *sortOperators;
3206         bool       *nullsFirst;
3207
3208         /*
3209          * We will need at most list_length(groupcls) sort columns; possibly less
3210          */
3211         numsortkeys = list_length(groupcls);
3212         sortColIdx = (AttrNumber *) palloc(numsortkeys * sizeof(AttrNumber));
3213         sortOperators = (Oid *) palloc(numsortkeys * sizeof(Oid));
3214         nullsFirst = (bool *) palloc(numsortkeys * sizeof(bool));
3215
3216         numsortkeys = 0;
3217
3218         foreach(l, groupcls)
3219         {
3220                 SortGroupClause *grpcl = (SortGroupClause *) lfirst(l);
3221                 TargetEntry *tle = get_tle_by_resno(sub_tlist, grpColIdx[grpno]);
3222
3223                 /*
3224                  * Check for the possibility of duplicate group-by clauses --- the
3225                  * parser should have removed 'em, but no point in sorting
3226                  * redundantly.
3227                  */
3228                 numsortkeys = add_sort_column(tle->resno, grpcl->sortop,
3229                                                                           grpcl->nulls_first,
3230                                                                           numsortkeys,
3231                                                                           sortColIdx, sortOperators, nullsFirst);
3232                 grpno++;
3233         }
3234
3235         Assert(numsortkeys > 0);
3236
3237         return make_sort(root, lefttree, numsortkeys,
3238                                          sortColIdx, sortOperators, nullsFirst, -1.0);
3239 }
3240
3241 static Material *
3242 make_material(Plan *lefttree)
3243 {
3244         Material   *node = makeNode(Material);
3245         Plan       *plan = &node->plan;
3246
3247         /* cost should be inserted by caller */
3248         plan->targetlist = lefttree->targetlist;
3249         plan->qual = NIL;
3250         plan->lefttree = lefttree;
3251         plan->righttree = NULL;
3252
3253         return node;
3254 }
3255
3256 /*
3257  * materialize_finished_plan: stick a Material node atop a completed plan
3258  *
3259  * There are a couple of places where we want to attach a Material node
3260  * after completion of subquery_planner().      This currently requires hackery.
3261  * Since subquery_planner has already run SS_finalize_plan on the subplan
3262  * tree, we have to kluge up parameter lists for the Material node.
3263  * Possibly this could be fixed by postponing SS_finalize_plan processing
3264  * until setrefs.c is run?
3265  */
3266 Plan *
3267 materialize_finished_plan(Plan *subplan)
3268 {
3269         Plan       *matplan;
3270         Path            matpath;                /* dummy for result of cost_material */
3271
3272         matplan = (Plan *) make_material(subplan);
3273
3274         /* Set cost data */
3275         cost_material(&matpath,
3276                                   subplan->startup_cost,
3277                                   subplan->total_cost,
3278                                   subplan->plan_rows,
3279                                   subplan->plan_width);
3280         matplan->startup_cost = matpath.startup_cost;
3281         matplan->total_cost = matpath.total_cost;
3282         matplan->plan_rows = subplan->plan_rows;
3283         matplan->plan_width = subplan->plan_width;
3284
3285         /* parameter kluge --- see comments above */
3286         matplan->extParam = bms_copy(subplan->extParam);
3287         matplan->allParam = bms_copy(subplan->allParam);
3288
3289         return matplan;
3290 }
3291
3292 Agg *
3293 make_agg(PlannerInfo *root, List *tlist, List *qual,
3294                  AggStrategy aggstrategy,
3295                  int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators,
3296                  long numGroups, int numAggs,
3297                  Plan *lefttree)
3298 {
3299         Agg                *node = makeNode(Agg);
3300         Plan       *plan = &node->plan;
3301         Path            agg_path;               /* dummy for result of cost_agg */
3302         QualCost        qual_cost;
3303
3304         node->aggstrategy = aggstrategy;
3305         node->numCols = numGroupCols;
3306         node->grpColIdx = grpColIdx;
3307         node->grpOperators = grpOperators;
3308         node->numGroups = numGroups;
3309
3310         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3311         cost_agg(&agg_path, root,
3312                          aggstrategy, numAggs,
3313                          numGroupCols, numGroups,
3314                          lefttree->startup_cost,
3315                          lefttree->total_cost,
3316                          lefttree->plan_rows);
3317         plan->startup_cost = agg_path.startup_cost;
3318         plan->total_cost = agg_path.total_cost;
3319
3320         /*
3321          * We will produce a single output tuple if not grouping, and a tuple per
3322          * group otherwise.
3323          */
3324         if (aggstrategy == AGG_PLAIN)
3325                 plan->plan_rows = 1;
3326         else
3327                 plan->plan_rows = numGroups;
3328
3329         /*
3330          * We also need to account for the cost of evaluation of the qual (ie, the
3331          * HAVING clause) and the tlist.  Note that cost_qual_eval doesn't charge
3332          * anything for Aggref nodes; this is okay since they are really
3333          * comparable to Vars.
3334          *
3335          * See notes in grouping_planner about why only make_agg, make_windowagg
3336          * and make_group worry about tlist eval cost.
3337          */
3338         if (qual)
3339         {
3340                 cost_qual_eval(&qual_cost, qual, root);
3341                 plan->startup_cost += qual_cost.startup;
3342                 plan->total_cost += qual_cost.startup;
3343                 plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3344         }
3345         cost_qual_eval(&qual_cost, tlist, root);
3346         plan->startup_cost += qual_cost.startup;
3347         plan->total_cost += qual_cost.startup;
3348         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3349
3350         plan->qual = qual;
3351         plan->targetlist = tlist;
3352         plan->lefttree = lefttree;
3353         plan->righttree = NULL;
3354
3355         return node;
3356 }
3357
3358 WindowAgg *
3359 make_windowagg(PlannerInfo *root, List *tlist,
3360                            int numWindowFuncs, Index winref,
3361                            int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
3362                            int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
3363                            int frameOptions, Plan *lefttree)
3364 {
3365         WindowAgg  *node = makeNode(WindowAgg);
3366         Plan       *plan = &node->plan;
3367         Path            windowagg_path; /* dummy for result of cost_windowagg */
3368         QualCost        qual_cost;
3369
3370         node->winref = winref;
3371         node->partNumCols = partNumCols;
3372         node->partColIdx = partColIdx;
3373         node->partOperators = partOperators;
3374         node->ordNumCols = ordNumCols;
3375         node->ordColIdx = ordColIdx;
3376         node->ordOperators = ordOperators;
3377         node->frameOptions = frameOptions;
3378
3379         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3380         cost_windowagg(&windowagg_path, root,
3381                                    numWindowFuncs, partNumCols, ordNumCols,
3382                                    lefttree->startup_cost,
3383                                    lefttree->total_cost,
3384                                    lefttree->plan_rows);
3385         plan->startup_cost = windowagg_path.startup_cost;
3386         plan->total_cost = windowagg_path.total_cost;
3387
3388         /*
3389          * We also need to account for the cost of evaluation of the tlist.
3390          *
3391          * See notes in grouping_planner about why only make_agg, make_windowagg
3392          * and make_group worry about tlist eval cost.
3393          */
3394         cost_qual_eval(&qual_cost, tlist, root);
3395         plan->startup_cost += qual_cost.startup;
3396         plan->total_cost += qual_cost.startup;
3397         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3398
3399         plan->targetlist = tlist;
3400         plan->lefttree = lefttree;
3401         plan->righttree = NULL;
3402         /* WindowAgg nodes never have a qual clause */
3403         plan->qual = NIL;
3404
3405         return node;
3406 }
3407
3408 Group *
3409 make_group(PlannerInfo *root,
3410                    List *tlist,
3411                    List *qual,
3412                    int numGroupCols,
3413                    AttrNumber *grpColIdx,
3414                    Oid *grpOperators,
3415                    double numGroups,
3416                    Plan *lefttree)
3417 {
3418         Group      *node = makeNode(Group);
3419         Plan       *plan = &node->plan;
3420         Path            group_path;             /* dummy for result of cost_group */
3421         QualCost        qual_cost;
3422
3423         node->numCols = numGroupCols;
3424         node->grpColIdx = grpColIdx;
3425         node->grpOperators = grpOperators;
3426
3427         copy_plan_costsize(plan, lefttree); /* only care about copying size */
3428         cost_group(&group_path, root,
3429                            numGroupCols, numGroups,
3430                            lefttree->startup_cost,
3431                            lefttree->total_cost,
3432                            lefttree->plan_rows);
3433         plan->startup_cost = group_path.startup_cost;
3434         plan->total_cost = group_path.total_cost;
3435
3436         /* One output tuple per estimated result group */
3437         plan->plan_rows = numGroups;
3438
3439         /*
3440          * We also need to account for the cost of evaluation of the qual (ie, the
3441          * HAVING clause) and the tlist.
3442          *
3443          * XXX this double-counts the cost of evaluation of any expressions used
3444          * for grouping, since in reality those will have been evaluated at a
3445          * lower plan level and will only be copied by the Group node. Worth
3446          * fixing?
3447          *
3448          * See notes in grouping_planner about why only make_agg, make_windowagg
3449          * and make_group worry about tlist eval cost.
3450          */
3451         if (qual)
3452         {
3453                 cost_qual_eval(&qual_cost, qual, root);
3454                 plan->startup_cost += qual_cost.startup;
3455                 plan->total_cost += qual_cost.startup;
3456                 plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3457         }
3458         cost_qual_eval(&qual_cost, tlist, root);
3459         plan->startup_cost += qual_cost.startup;
3460         plan->total_cost += qual_cost.startup;
3461         plan->total_cost += qual_cost.per_tuple * plan->plan_rows;
3462
3463         plan->qual = qual;
3464         plan->targetlist = tlist;
3465         plan->lefttree = lefttree;
3466         plan->righttree = NULL;
3467
3468         return node;
3469 }
3470
3471 /*
3472  * distinctList is a list of SortGroupClauses, identifying the targetlist items
3473  * that should be considered by the Unique filter.      The input path must
3474  * already be sorted accordingly.
3475  */
3476 Unique *
3477 make_unique(Plan *lefttree, List *distinctList)
3478 {
3479         Unique     *node = makeNode(Unique);
3480         Plan       *plan = &node->plan;
3481         int                     numCols = list_length(distinctList);
3482         int                     keyno = 0;
3483         AttrNumber *uniqColIdx;
3484         Oid                *uniqOperators;
3485         ListCell   *slitem;
3486
3487         copy_plan_costsize(plan, lefttree);
3488
3489         /*
3490          * Charge one cpu_operator_cost per comparison per input tuple. We assume
3491          * all columns get compared at most of the tuples.      (XXX probably this is
3492          * an overestimate.)
3493          */
3494         plan->total_cost += cpu_operator_cost * plan->plan_rows * numCols;
3495
3496         /*
3497          * plan->plan_rows is left as a copy of the input subplan's plan_rows; ie,
3498          * we assume the filter removes nothing.  The caller must alter this if he
3499          * has a better idea.
3500          */
3501
3502         plan->targetlist = lefttree->targetlist;
3503         plan->qual = NIL;
3504         plan->lefttree = lefttree;
3505         plan->righttree = NULL;
3506
3507         /*
3508          * convert SortGroupClause list into arrays of attr indexes and equality
3509          * operators, as wanted by executor
3510          */
3511         Assert(numCols > 0);
3512         uniqColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
3513         uniqOperators = (Oid *) palloc(sizeof(Oid) * numCols);
3514
3515         foreach(slitem, distinctList)
3516         {
3517                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
3518                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, plan->targetlist);
3519
3520                 uniqColIdx[keyno] = tle->resno;
3521                 uniqOperators[keyno] = sortcl->eqop;
3522                 Assert(OidIsValid(uniqOperators[keyno]));
3523                 keyno++;
3524         }
3525
3526         node->numCols = numCols;
3527         node->uniqColIdx = uniqColIdx;
3528         node->uniqOperators = uniqOperators;
3529
3530         return node;
3531 }
3532
3533 /*
3534  * distinctList is a list of SortGroupClauses, identifying the targetlist
3535  * items that should be considered by the SetOp filter.  The input path must
3536  * already be sorted accordingly.
3537  */
3538 SetOp *
3539 make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
3540                    List *distinctList, AttrNumber flagColIdx, int firstFlag,
3541                    long numGroups, double outputRows)
3542 {
3543         SetOp      *node = makeNode(SetOp);
3544         Plan       *plan = &node->plan;
3545         int                     numCols = list_length(distinctList);
3546         int                     keyno = 0;
3547         AttrNumber *dupColIdx;
3548         Oid                *dupOperators;
3549         ListCell   *slitem;
3550
3551         copy_plan_costsize(plan, lefttree);
3552         plan->plan_rows = outputRows;
3553
3554         /*
3555          * Charge one cpu_operator_cost per comparison per input tuple. We assume
3556          * all columns get compared at most of the tuples.
3557          */
3558         plan->total_cost += cpu_operator_cost * lefttree->plan_rows * numCols;
3559
3560         plan->targetlist = lefttree->targetlist;
3561         plan->qual = NIL;
3562         plan->lefttree = lefttree;
3563         plan->righttree = NULL;
3564
3565         /*
3566          * convert SortGroupClause list into arrays of attr indexes and equality
3567          * operators, as wanted by executor
3568          */
3569         Assert(numCols > 0);
3570         dupColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
3571         dupOperators = (Oid *) palloc(sizeof(Oid) * numCols);
3572
3573         foreach(slitem, distinctList)
3574         {
3575                 SortGroupClause *sortcl = (SortGroupClause *) lfirst(slitem);
3576                 TargetEntry *tle = get_sortgroupclause_tle(sortcl, plan->targetlist);
3577
3578                 dupColIdx[keyno] = tle->resno;
3579                 dupOperators[keyno] = sortcl->eqop;
3580                 Assert(OidIsValid(dupOperators[keyno]));
3581                 keyno++;
3582         }
3583
3584         node->cmd = cmd;
3585         node->strategy = strategy;
3586         node->numCols = numCols;
3587         node->dupColIdx = dupColIdx;
3588         node->dupOperators = dupOperators;
3589         node->flagColIdx = flagColIdx;
3590         node->firstFlag = firstFlag;
3591         node->numGroups = numGroups;
3592
3593         return node;
3594 }
3595
3596 /*
3597  * make_lockrows
3598  *        Build a LockRows plan node
3599  */
3600 LockRows *
3601 make_lockrows(Plan *lefttree, List *rowMarks)
3602 {
3603         LockRows   *node = makeNode(LockRows);
3604         Plan       *plan = &node->plan;
3605
3606         copy_plan_costsize(plan, lefttree);
3607
3608         /* charge cpu_tuple_cost to reflect locking costs (underestimate?) */
3609         plan->total_cost += cpu_tuple_cost * plan->plan_rows;
3610
3611         plan->targetlist = lefttree->targetlist;
3612         plan->qual = NIL;
3613         plan->lefttree = lefttree;
3614         plan->righttree = NULL;
3615
3616         node->rowMarks = rowMarks;
3617
3618         return node;
3619 }
3620
3621 /*
3622  * Note: offset_est and count_est are passed in to save having to repeat
3623  * work already done to estimate the values of the limitOffset and limitCount
3624  * expressions.  Their values are as returned by preprocess_limit (0 means
3625  * "not relevant", -1 means "couldn't estimate").  Keep the code below in sync
3626  * with that function!
3627  */
3628 Limit *
3629 make_limit(Plan *lefttree, Node *limitOffset, Node *limitCount,
3630                    int64 offset_est, int64 count_est)
3631 {
3632         Limit      *node = makeNode(Limit);
3633         Plan       *plan = &node->plan;
3634
3635         copy_plan_costsize(plan, lefttree);
3636
3637         /*
3638          * Adjust the output rows count and costs according to the offset/limit.
3639          * This is only a cosmetic issue if we are at top level, but if we are
3640          * building a subquery then it's important to report correct info to the
3641          * outer planner.
3642          *
3643          * When the offset or count couldn't be estimated, use 10% of the
3644          * estimated number of rows emitted from the subplan.
3645          */
3646         if (offset_est != 0)
3647         {
3648                 double          offset_rows;
3649
3650                 if (offset_est > 0)
3651                         offset_rows = (double) offset_est;
3652                 else
3653                         offset_rows = clamp_row_est(lefttree->plan_rows * 0.10);
3654                 if (offset_rows > plan->plan_rows)
3655                         offset_rows = plan->plan_rows;
3656                 if (plan->plan_rows > 0)
3657                         plan->startup_cost +=
3658                                 (plan->total_cost - plan->startup_cost)
3659                                 * offset_rows / plan->plan_rows;
3660                 plan->plan_rows -= offset_rows;
3661                 if (plan->plan_rows < 1)
3662                         plan->plan_rows = 1;
3663         }
3664
3665         if (count_est != 0)
3666         {
3667                 double          count_rows;
3668
3669                 if (count_est > 0)
3670                         count_rows = (double) count_est;
3671                 else
3672                         count_rows = clamp_row_est(lefttree->plan_rows * 0.10);
3673                 if (count_rows > plan->plan_rows)
3674                         count_rows = plan->plan_rows;
3675                 if (plan->plan_rows > 0)
3676                         plan->total_cost = plan->startup_cost +
3677                                 (plan->total_cost - plan->startup_cost)
3678                                 * count_rows / plan->plan_rows;
3679                 plan->plan_rows = count_rows;
3680                 if (plan->plan_rows < 1)
3681                         plan->plan_rows = 1;
3682         }
3683
3684         plan->targetlist = lefttree->targetlist;
3685         plan->qual = NIL;
3686         plan->lefttree = lefttree;
3687         plan->righttree = NULL;
3688
3689         node->limitOffset = limitOffset;
3690         node->limitCount = limitCount;
3691
3692         return node;
3693 }
3694
3695 /*
3696  * make_result
3697  *        Build a Result plan node
3698  *
3699  * If we have a subplan, assume that any evaluation costs for the gating qual
3700  * were already factored into the subplan's startup cost, and just copy the
3701  * subplan cost.  If there's no subplan, we should include the qual eval
3702  * cost.  In either case, tlist eval cost is not to be included here.
3703  */
3704 Result *
3705 make_result(PlannerInfo *root,
3706                         List *tlist,
3707                         Node *resconstantqual,
3708                         Plan *subplan)
3709 {
3710         Result     *node = makeNode(Result);
3711         Plan       *plan = &node->plan;
3712
3713         if (subplan)
3714                 copy_plan_costsize(plan, subplan);
3715         else
3716         {
3717                 plan->startup_cost = 0;
3718                 plan->total_cost = cpu_tuple_cost;
3719                 plan->plan_rows = 1;    /* wrong if we have a set-valued function? */
3720                 plan->plan_width = 0;   /* XXX is it worth being smarter? */
3721                 if (resconstantqual)
3722                 {
3723                         QualCost        qual_cost;
3724
3725                         cost_qual_eval(&qual_cost, (List *) resconstantqual, root);
3726                         /* resconstantqual is evaluated once at startup */
3727                         plan->startup_cost += qual_cost.startup + qual_cost.per_tuple;
3728                         plan->total_cost += qual_cost.startup + qual_cost.per_tuple;
3729                 }
3730         }
3731
3732         plan->targetlist = tlist;
3733         plan->qual = NIL;
3734         plan->lefttree = subplan;
3735         plan->righttree = NULL;
3736         node->resconstantqual = resconstantqual;
3737
3738         return node;
3739 }
3740
3741 /*
3742  * make_modifytable
3743  *        Build a ModifyTable plan node
3744  *
3745  * Currently, we don't charge anything extra for the actual table modification
3746  * work, nor for the RETURNING expressions if any.  It would only be window
3747  * dressing, since these are always top-level nodes and there is no way for
3748  * the costs to change any higher-level planning choices.  But we might want
3749  * to make it look better sometime.
3750  */
3751 ModifyTable *
3752 make_modifytable(CmdType operation, List *resultRelations,
3753                                  List *subplans, List *returningLists)
3754 {
3755         ModifyTable *node = makeNode(ModifyTable);
3756         Plan       *plan = &node->plan;
3757         double          total_size;
3758         ListCell   *subnode;
3759
3760         Assert(list_length(resultRelations) == list_length(subplans));
3761         Assert(returningLists == NIL ||
3762                    list_length(resultRelations) == list_length(returningLists));
3763
3764         /*
3765          * Compute cost as sum of subplan costs.
3766          */
3767         plan->startup_cost = 0;
3768         plan->total_cost = 0;
3769         plan->plan_rows = 0;
3770         total_size = 0;
3771         foreach(subnode, subplans)
3772         {
3773                 Plan       *subplan = (Plan *) lfirst(subnode);
3774
3775                 if (subnode == list_head(subplans))     /* first node? */
3776                         plan->startup_cost = subplan->startup_cost;
3777                 plan->total_cost += subplan->total_cost;
3778                 plan->plan_rows += subplan->plan_rows;
3779                 total_size += subplan->plan_width * subplan->plan_rows;
3780         }
3781         if (plan->plan_rows > 0)
3782                 plan->plan_width = rint(total_size / plan->plan_rows);
3783         else
3784                 plan->plan_width = 0;
3785
3786         node->plan.lefttree = NULL;
3787         node->plan.righttree = NULL;
3788         node->plan.qual = NIL;
3789
3790         /*
3791          * Set up the visible plan targetlist as being the same as the first
3792          * RETURNING list.  This is for the use of EXPLAIN; the executor won't
3793          * pay any attention to the targetlist.
3794          */
3795         if (returningLists)
3796                 node->plan.targetlist = copyObject(linitial(returningLists));
3797         else
3798                 node->plan.targetlist = NIL;
3799
3800         node->operation = operation;
3801         node->resultRelations = resultRelations;
3802         node->plans = subplans;
3803         node->returningLists = returningLists;
3804
3805         return node;
3806 }
3807
3808 /*
3809  * is_projection_capable_plan
3810  *              Check whether a given Plan node is able to do projection.
3811  */
3812 bool
3813 is_projection_capable_plan(Plan *plan)
3814 {
3815         /* Most plan types can project, so just list the ones that can't */
3816         switch (nodeTag(plan))
3817         {
3818                 case T_Hash:
3819                 case T_Material:
3820                 case T_Sort:
3821                 case T_Unique:
3822                 case T_SetOp:
3823                 case T_LockRows:
3824                 case T_Limit:
3825                 case T_ModifyTable:
3826                 case T_Append:
3827                 case T_RecursiveUnion:
3828                         return false;
3829                 default:
3830                         break;
3831         }
3832         return true;
3833 }