granicus.if.org Git - postgresql/blob - src/backend/executor/execMain.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * execMain.c
   4  *        top level executor interface routines
   5  *
   6  * INTERFACE ROUTINES
   7  *      ExecutorStart()
   8  *      ExecutorRun()
   9  *      ExecutorFinish()
  10  *      ExecutorEnd()
  11  *
  12  *      These four procedures are the external interface to the executor.
  13  *      In each case, the query descriptor is required as an argument.
  14  *
  15  *      ExecutorStart must be called at the beginning of execution of any
  16  *      query plan and ExecutorEnd must always be called at the end of
  17  *      execution of a plan (unless it is aborted due to error).
  18  *
  19  *      ExecutorRun accepts direction and count arguments that specify whether
  20  *      the plan is to be executed forwards, backwards, and for how many tuples.
  21  *      In some cases ExecutorRun may be called multiple times to process all
  22  *      the tuples for a plan.  It is also acceptable to stop short of executing
  23  *      the whole plan (but only if it is a SELECT).
  24  *
  25  *      ExecutorFinish must be called after the final ExecutorRun call and
  26  *      before ExecutorEnd.  This can be omitted only in case of EXPLAIN,
  27  *      which should also omit ExecutorRun.
  28  *
  29  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
  30  * Portions Copyright (c) 1994, Regents of the University of California
  31  *
  32  *
  33  * IDENTIFICATION
  34  *        src/backend/executor/execMain.c
  35  *
  36  *-------------------------------------------------------------------------
  37  */
  38 #include "postgres.h"
  39
  40 #include "access/htup_details.h"
  41 #include "access/sysattr.h"
  42 #include "access/transam.h"
  43 #include "access/xact.h"
  44 #include "catalog/namespace.h"
  45 #include "catalog/partition.h"
  46 #include "commands/matview.h"
  47 #include "commands/trigger.h"
  48 #include "executor/execdebug.h"
  49 #include "foreign/fdwapi.h"
  50 #include "mb/pg_wchar.h"
  51 #include "miscadmin.h"
  52 #include "optimizer/clauses.h"
  53 #include "parser/parsetree.h"
  54 #include "rewrite/rewriteManip.h"
  55 #include "storage/bufmgr.h"
  56 #include "storage/lmgr.h"
  57 #include "tcop/utility.h"
  58 #include "utils/acl.h"
  59 #include "utils/lsyscache.h"
  60 #include "utils/memutils.h"
  61 #include "utils/rls.h"
  62 #include "utils/snapmgr.h"
  63 #include "utils/tqual.h"
  64
  65
  66 /* Hooks for plugins to get control in ExecutorStart/Run/Finish/End */
  67 ExecutorStart_hook_type ExecutorStart_hook = NULL;
  68 ExecutorRun_hook_type ExecutorRun_hook = NULL;
  69 ExecutorFinish_hook_type ExecutorFinish_hook = NULL;
  70 ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
  71
  72 /* Hook for plugin to get control in ExecCheckRTPerms() */
  73 ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
  74
  75 /* decls for local routines only used within this module */
  76 static void InitPlan(QueryDesc *queryDesc, int eflags);
  77 static void CheckValidRowMarkRel(Relation rel, RowMarkType markType);
  78 static void ExecPostprocessPlan(EState *estate);
  79 static void ExecEndPlan(PlanState *planstate, EState *estate);
  80 static void ExecutePlan(EState *estate, PlanState *planstate,
  81                         bool use_parallel_mode,
  82                         CmdType operation,
  83                         bool sendTuples,
  84                         uint64 numberTuples,
  85                         ScanDirection direction,
  86                         DestReceiver *dest);
  87 static bool ExecCheckRTEPerms(RangeTblEntry *rte);
  88 static bool ExecCheckRTEPermsModified(Oid relOid, Oid userid,
  89                                                   Bitmapset *modifiedCols,
  90                                                   AclMode requiredPerms);
  91 static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
  92 static char *ExecBuildSlotValueDescription(Oid reloid,
  93                                                           TupleTableSlot *slot,
  94                                                           TupleDesc tupdesc,
  95                                                           Bitmapset *modifiedCols,
  96                                                           int maxfieldlen);
  97 static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
  98                                   Plan *planTree);
  99
 100 /*
 101  * Note that GetUpdatedColumns() also exists in commands/trigger.c.  There does
 102  * not appear to be any good header to put it into, given the structures that
 103  * it uses, so we let them be duplicated.  Be sure to update both if one needs
 104  * to be changed, however.
 105  */
 106 #define GetInsertedColumns(relinfo, estate) \
 107         (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->insertedCols)
 108 #define GetUpdatedColumns(relinfo, estate) \
 109         (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->updatedCols)
 110
 111 /* end of local decls */
 112
 113
 114 /* ----------------------------------------------------------------
 115  *              ExecutorStart
 116  *
 117  *              This routine must be called at the beginning of any execution of any
 118  *              query plan
 119  *
 120  * Takes a QueryDesc previously created by CreateQueryDesc (which is separate
 121  * only because some places use QueryDescs for utility commands).  The tupDesc
 122  * field of the QueryDesc is filled in to describe the tuples that will be
 123  * returned, and the internal fields (estate and planstate) are set up.
 124  *
 125  * eflags contains flag bits as described in executor.h.
 126  *
 127  * NB: the CurrentMemoryContext when this is called will become the parent
 128  * of the per-query context used for this Executor invocation.
 129  *
 130  * We provide a function hook variable that lets loadable plugins
 131  * get control when ExecutorStart is called.  Such a plugin would
 132  * normally call standard_ExecutorStart().
 133  *
 134  * ----------------------------------------------------------------
 135  */
 136 void
 137 ExecutorStart(QueryDesc *queryDesc, int eflags)
 138 {
 139         if (ExecutorStart_hook)
 140                 (*ExecutorStart_hook) (queryDesc, eflags);
 141         else
 142                 standard_ExecutorStart(queryDesc, eflags);
 143 }
 144
 145 void
 146 standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
 147 {
 148         EState     *estate;
 149         MemoryContext oldcontext;
 150
 151         /* sanity checks: queryDesc must not be started already */
 152         Assert(queryDesc != NULL);
 153         Assert(queryDesc->estate == NULL);
 154
 155         /*
 156          * If the transaction is read-only, we need to check if any writes are
 157          * planned to non-temporary tables.  EXPLAIN is considered read-only.
 158          *
 159          * Don't allow writes in parallel mode.  Supporting UPDATE and DELETE
 160          * would require (a) storing the combocid hash in shared memory, rather
 161          * than synchronizing it just once at the start of parallelism, and (b) an
 162          * alternative to heap_update()'s reliance on xmax for mutual exclusion.
 163          * INSERT may have no such troubles, but we forbid it to simplify the
 164          * checks.
 165          *
 166          * We have lower-level defenses in CommandCounterIncrement and elsewhere
 167          * against performing unsafe operations in parallel mode, but this gives a
 168          * more user-friendly error message.
 169          */
 170         if ((XactReadOnly || IsInParallelMode()) &&
 171                 !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
 172                 ExecCheckXactReadOnly(queryDesc->plannedstmt);
 173
 174         /*
 175          * Build EState, switch into per-query memory context for startup.
 176          */
 177         estate = CreateExecutorState();
 178         queryDesc->estate = estate;
 179
 180         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 181
 182         /*
 183          * Fill in external parameters, if any, from queryDesc; and allocate
 184          * workspace for internal parameters
 185          */
 186         estate->es_param_list_info = queryDesc->params;
 187
 188         if (queryDesc->plannedstmt->nParamExec > 0)
 189                 estate->es_param_exec_vals = (ParamExecData *)
 190                         palloc0(queryDesc->plannedstmt->nParamExec * sizeof(ParamExecData));
 191
 192         /*
 193          * If non-read-only query, set the command ID to mark output tuples with
 194          */
 195         switch (queryDesc->operation)
 196         {
 197                 case CMD_SELECT:
 198
 199                         /*
 200                          * SELECT FOR [KEY] UPDATE/SHARE and modifying CTEs need to mark
 201                          * tuples
 202                          */
 203                         if (queryDesc->plannedstmt->rowMarks != NIL ||
 204                                 queryDesc->plannedstmt->hasModifyingCTE)
 205                                 estate->es_output_cid = GetCurrentCommandId(true);
 206
 207                         /*
 208                          * A SELECT without modifying CTEs can't possibly queue triggers,
 209                          * so force skip-triggers mode. This is just a marginal efficiency
 210                          * hack, since AfterTriggerBeginQuery/AfterTriggerEndQuery aren't
 211                          * all that expensive, but we might as well do it.
 212                          */
 213                         if (!queryDesc->plannedstmt->hasModifyingCTE)
 214                                 eflags |= EXEC_FLAG_SKIP_TRIGGERS;
 215                         break;
 216
 217                 case CMD_INSERT:
 218                 case CMD_DELETE:
 219                 case CMD_UPDATE:
 220                         estate->es_output_cid = GetCurrentCommandId(true);
 221                         break;
 222
 223                 default:
 224                         elog(ERROR, "unrecognized operation code: %d",
 225                                  (int) queryDesc->operation);
 226                         break;
 227         }
 228
 229         /*
 230          * Copy other important information into the EState
 231          */
 232         estate->es_snapshot = RegisterSnapshot(queryDesc->snapshot);
 233         estate->es_crosscheck_snapshot = RegisterSnapshot(queryDesc->crosscheck_snapshot);
 234         estate->es_top_eflags = eflags;
 235         estate->es_instrument = queryDesc->instrument_options;
 236
 237         /*
 238          * Initialize the plan state tree
 239          */
 240         InitPlan(queryDesc, eflags);
 241
 242         /*
 243          * Set up an AFTER-trigger statement context, unless told not to, or
 244          * unless it's EXPLAIN-only mode (when ExecutorFinish won't be called).
 245          */
 246         if (!(eflags & (EXEC_FLAG_SKIP_TRIGGERS | EXEC_FLAG_EXPLAIN_ONLY)))
 247                 AfterTriggerBeginQuery();
 248
 249         MemoryContextSwitchTo(oldcontext);
 250 }
 251
 252 /* ----------------------------------------------------------------
 253  *              ExecutorRun
 254  *
 255  *              This is the main routine of the executor module. It accepts
 256  *              the query descriptor from the traffic cop and executes the
 257  *              query plan.
 258  *
 259  *              ExecutorStart must have been called already.
 260  *
 261  *              If direction is NoMovementScanDirection then nothing is done
 262  *              except to start up/shut down the destination.  Otherwise,
 263  *              we retrieve up to 'count' tuples in the specified direction.
 264  *
 265  *              Note: count = 0 is interpreted as no portal limit, i.e., run to
 266  *              completion.  Also note that the count limit is only applied to
 267  *              retrieved tuples, not for instance to those inserted/updated/deleted
 268  *              by a ModifyTable plan node.
 269  *
 270  *              There is no return value, but output tuples (if any) are sent to
 271  *              the destination receiver specified in the QueryDesc; and the number
 272  *              of tuples processed at the top level can be found in
 273  *              estate->es_processed.
 274  *
 275  *              We provide a function hook variable that lets loadable plugins
 276  *              get control when ExecutorRun is called.  Such a plugin would
 277  *              normally call standard_ExecutorRun().
 278  *
 279  * ----------------------------------------------------------------
 280  */
 281 void
 282 ExecutorRun(QueryDesc *queryDesc,
 283                         ScanDirection direction, uint64 count)
 284 {
 285         if (ExecutorRun_hook)
 286                 (*ExecutorRun_hook) (queryDesc, direction, count);
 287         else
 288                 standard_ExecutorRun(queryDesc, direction, count);
 289 }
 290
 291 void
 292 standard_ExecutorRun(QueryDesc *queryDesc,
 293                                          ScanDirection direction, uint64 count)
 294 {
 295         EState     *estate;
 296         CmdType         operation;
 297         DestReceiver *dest;
 298         bool            sendTuples;
 299         MemoryContext oldcontext;
 300
 301         /* sanity checks */
 302         Assert(queryDesc != NULL);
 303
 304         estate = queryDesc->estate;
 305
 306         Assert(estate != NULL);
 307         Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
 308
 309         /*
 310          * Switch into per-query memory context
 311          */
 312         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 313
 314         /* Allow instrumentation of Executor overall runtime */
 315         if (queryDesc->totaltime)
 316                 InstrStartNode(queryDesc->totaltime);
 317
 318         /*
 319          * extract information from the query descriptor and the query feature.
 320          */
 321         operation = queryDesc->operation;
 322         dest = queryDesc->dest;
 323
 324         /*
 325          * startup tuple receiver, if we will be emitting tuples
 326          */
 327         estate->es_processed = 0;
 328         estate->es_lastoid = InvalidOid;
 329
 330         sendTuples = (operation == CMD_SELECT ||
 331                                   queryDesc->plannedstmt->hasReturning);
 332
 333         if (sendTuples)
 334                 (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
 335
 336         /*
 337          * run plan
 338          */
 339         if (!ScanDirectionIsNoMovement(direction))
 340                 ExecutePlan(estate,
 341                                         queryDesc->planstate,
 342                                         queryDesc->plannedstmt->parallelModeNeeded,
 343                                         operation,
 344                                         sendTuples,
 345                                         count,
 346                                         direction,
 347                                         dest);
 348
 349         /*
 350          * shutdown tuple receiver, if we started it
 351          */
 352         if (sendTuples)
 353                 (*dest->rShutdown) (dest);
 354
 355         if (queryDesc->totaltime)
 356                 InstrStopNode(queryDesc->totaltime, estate->es_processed);
 357
 358         MemoryContextSwitchTo(oldcontext);
 359 }
 360
 361 /* ----------------------------------------------------------------
 362  *              ExecutorFinish
 363  *
 364  *              This routine must be called after the last ExecutorRun call.
 365  *              It performs cleanup such as firing AFTER triggers.  It is
 366  *              separate from ExecutorEnd because EXPLAIN ANALYZE needs to
 367  *              include these actions in the total runtime.
 368  *
 369  *              We provide a function hook variable that lets loadable plugins
 370  *              get control when ExecutorFinish is called.  Such a plugin would
 371  *              normally call standard_ExecutorFinish().
 372  *
 373  * ----------------------------------------------------------------
 374  */
 375 void
 376 ExecutorFinish(QueryDesc *queryDesc)
 377 {
 378         if (ExecutorFinish_hook)
 379                 (*ExecutorFinish_hook) (queryDesc);
 380         else
 381                 standard_ExecutorFinish(queryDesc);
 382 }
 383
 384 void
 385 standard_ExecutorFinish(QueryDesc *queryDesc)
 386 {
 387         EState     *estate;
 388         MemoryContext oldcontext;
 389
 390         /* sanity checks */
 391         Assert(queryDesc != NULL);
 392
 393         estate = queryDesc->estate;
 394
 395         Assert(estate != NULL);
 396         Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
 397
 398         /* This should be run once and only once per Executor instance */
 399         Assert(!estate->es_finished);
 400
 401         /* Switch into per-query memory context */
 402         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 403
 404         /* Allow instrumentation of Executor overall runtime */
 405         if (queryDesc->totaltime)
 406                 InstrStartNode(queryDesc->totaltime);
 407
 408         /* Run ModifyTable nodes to completion */
 409         ExecPostprocessPlan(estate);
 410
 411         /* Execute queued AFTER triggers, unless told not to */
 412         if (!(estate->es_top_eflags & EXEC_FLAG_SKIP_TRIGGERS))
 413                 AfterTriggerEndQuery(estate);
 414
 415         if (queryDesc->totaltime)
 416                 InstrStopNode(queryDesc->totaltime, 0);
 417
 418         MemoryContextSwitchTo(oldcontext);
 419
 420         estate->es_finished = true;
 421 }
 422
 423 /* ----------------------------------------------------------------
 424  *              ExecutorEnd
 425  *
 426  *              This routine must be called at the end of execution of any
 427  *              query plan
 428  *
 429  *              We provide a function hook variable that lets loadable plugins
 430  *              get control when ExecutorEnd is called.  Such a plugin would
 431  *              normally call standard_ExecutorEnd().
 432  *
 433  * ----------------------------------------------------------------
 434  */
 435 void
 436 ExecutorEnd(QueryDesc *queryDesc)
 437 {
 438         if (ExecutorEnd_hook)
 439                 (*ExecutorEnd_hook) (queryDesc);
 440         else
 441                 standard_ExecutorEnd(queryDesc);
 442 }
 443
 444 void
 445 standard_ExecutorEnd(QueryDesc *queryDesc)
 446 {
 447         EState     *estate;
 448         MemoryContext oldcontext;
 449
 450         /* sanity checks */
 451         Assert(queryDesc != NULL);
 452
 453         estate = queryDesc->estate;
 454
 455         Assert(estate != NULL);
 456
 457         /*
 458          * Check that ExecutorFinish was called, unless in EXPLAIN-only mode. This
 459          * Assert is needed because ExecutorFinish is new as of 9.1, and callers
 460          * might forget to call it.
 461          */
 462         Assert(estate->es_finished ||
 463                    (estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
 464
 465         /*
 466          * Switch into per-query memory context to run ExecEndPlan
 467          */
 468         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 469
 470         ExecEndPlan(queryDesc->planstate, estate);
 471
 472         /* do away with our snapshots */
 473         UnregisterSnapshot(estate->es_snapshot);
 474         UnregisterSnapshot(estate->es_crosscheck_snapshot);
 475
 476         /*
 477          * Must switch out of context before destroying it
 478          */
 479         MemoryContextSwitchTo(oldcontext);
 480
 481         /*
 482          * Release EState and per-query memory context.  This should release
 483          * everything the executor has allocated.
 484          */
 485         FreeExecutorState(estate);
 486
 487         /* Reset queryDesc fields that no longer point to anything */
 488         queryDesc->tupDesc = NULL;
 489         queryDesc->estate = NULL;
 490         queryDesc->planstate = NULL;
 491         queryDesc->totaltime = NULL;
 492 }
 493
 494 /* ----------------------------------------------------------------
 495  *              ExecutorRewind
 496  *
 497  *              This routine may be called on an open queryDesc to rewind it
 498  *              to the start.
 499  * ----------------------------------------------------------------
 500  */
 501 void
 502 ExecutorRewind(QueryDesc *queryDesc)
 503 {
 504         EState     *estate;
 505         MemoryContext oldcontext;
 506
 507         /* sanity checks */
 508         Assert(queryDesc != NULL);
 509
 510         estate = queryDesc->estate;
 511
 512         Assert(estate != NULL);
 513
 514         /* It's probably not sensible to rescan updating queries */
 515         Assert(queryDesc->operation == CMD_SELECT);
 516
 517         /*
 518          * Switch into per-query memory context
 519          */
 520         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 521
 522         /*
 523          * rescan plan
 524          */
 525         ExecReScan(queryDesc->planstate);
 526
 527         MemoryContextSwitchTo(oldcontext);
 528 }
 529
 530
 531 /*
 532  * ExecCheckRTPerms
 533  *              Check access permissions for all relations listed in a range table.
 534  *
 535  * Returns true if permissions are adequate.  Otherwise, throws an appropriate
 536  * error if ereport_on_violation is true, or simply returns false otherwise.
 537  *
 538  * Note that this does NOT address row level security policies (aka: RLS).  If
 539  * rows will be returned to the user as a result of this permission check
 540  * passing, then RLS also needs to be consulted (and check_enable_rls()).
 541  *
 542  * See rewrite/rowsecurity.c.
 543  */
 544 bool
 545 ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation)
 546 {
 547         ListCell   *l;
 548         bool            result = true;
 549
 550         foreach(l, rangeTable)
 551         {
 552                 RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
 553
 554                 result = ExecCheckRTEPerms(rte);
 555                 if (!result)
 556                 {
 557                         Assert(rte->rtekind == RTE_RELATION);
 558                         if (ereport_on_violation)
 559                                 aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
 560                                                            get_rel_name(rte->relid));
 561                         return false;
 562                 }
 563         }
 564
 565         if (ExecutorCheckPerms_hook)
 566                 result = (*ExecutorCheckPerms_hook) (rangeTable,
 567                                                                                          ereport_on_violation);
 568         return result;
 569 }
 570
 571 /*
 572  * ExecCheckRTEPerms
 573  *              Check access permissions for a single RTE.
 574  */
 575 static bool
 576 ExecCheckRTEPerms(RangeTblEntry *rte)
 577 {
 578         AclMode         requiredPerms;
 579         AclMode         relPerms;
 580         AclMode         remainingPerms;
 581         Oid                     relOid;
 582         Oid                     userid;
 583
 584         /*
 585          * Only plain-relation RTEs need to be checked here.  Function RTEs are
 586          * checked by init_fcache when the function is prepared for execution.
 587          * Join, subquery, and special RTEs need no checks.
 588          */
 589         if (rte->rtekind != RTE_RELATION)
 590                 return true;
 591
 592         /*
 593          * No work if requiredPerms is empty.
 594          */
 595         requiredPerms = rte->requiredPerms;
 596         if (requiredPerms == 0)
 597                 return true;
 598
 599         relOid = rte->relid;
 600
 601         /*
 602          * userid to check as: current user unless we have a setuid indication.
 603          *
 604          * Note: GetUserId() is presently fast enough that there's no harm in
 605          * calling it separately for each RTE.  If that stops being true, we could
 606          * call it once in ExecCheckRTPerms and pass the userid down from there.
 607          * But for now, no need for the extra clutter.
 608          */
 609         userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
 610
 611         /*
 612          * We must have *all* the requiredPerms bits, but some of the bits can be
 613          * satisfied from column-level rather than relation-level permissions.
 614          * First, remove any bits that are satisfied by relation permissions.
 615          */
 616         relPerms = pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL);
 617         remainingPerms = requiredPerms & ~relPerms;
 618         if (remainingPerms != 0)
 619         {
 620                 int                     col = -1;
 621
 622                 /*
 623                  * If we lack any permissions that exist only as relation permissions,
 624                  * we can fail straight away.
 625                  */
 626                 if (remainingPerms & ~(ACL_SELECT | ACL_INSERT | ACL_UPDATE))
 627                         return false;
 628
 629                 /*
 630                  * Check to see if we have the needed privileges at column level.
 631                  *
 632                  * Note: failures just report a table-level error; it would be nicer
 633                  * to report a column-level error if we have some but not all of the
 634                  * column privileges.
 635                  */
 636                 if (remainingPerms & ACL_SELECT)
 637                 {
 638                         /*
 639                          * When the query doesn't explicitly reference any columns (for
 640                          * example, SELECT COUNT(*) FROM table), allow the query if we
 641                          * have SELECT on any column of the rel, as per SQL spec.
 642                          */
 643                         if (bms_is_empty(rte->selectedCols))
 644                         {
 645                                 if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
 646                                                                                           ACLMASK_ANY) != ACLCHECK_OK)
 647                                         return false;
 648                         }
 649
 650                         while ((col = bms_next_member(rte->selectedCols, col)) >= 0)
 651                         {
 652                                 /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
 653                                 AttrNumber      attno = col + FirstLowInvalidHeapAttributeNumber;
 654
 655                                 if (attno == InvalidAttrNumber)
 656                                 {
 657                                         /* Whole-row reference, must have priv on all cols */
 658                                         if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
 659                                                                                                   ACLMASK_ALL) != ACLCHECK_OK)
 660                                                 return false;
 661                                 }
 662                                 else
 663                                 {
 664                                         if (pg_attribute_aclcheck(relOid, attno, userid,
 665                                                                                           ACL_SELECT) != ACLCHECK_OK)
 666                                                 return false;
 667                                 }
 668                         }
 669                 }
 670
 671                 /*
 672                  * Basically the same for the mod columns, for both INSERT and UPDATE
 673                  * privilege as specified by remainingPerms.
 674                  */
 675                 if (remainingPerms & ACL_INSERT && !ExecCheckRTEPermsModified(relOid,
 676                                                                                                                                           userid,
 677                                                                                                                    rte->insertedCols,
 678                                                                                                                                  ACL_INSERT))
 679                         return false;
 680
 681                 if (remainingPerms & ACL_UPDATE && !ExecCheckRTEPermsModified(relOid,
 682                                                                                                                                           userid,
 683                                                                                                                         rte->updatedCols,
 684                                                                                                                                  ACL_UPDATE))
 685                         return false;
 686         }
 687         return true;
 688 }
 689
 690 /*
 691  * ExecCheckRTEPermsModified
 692  *              Check INSERT or UPDATE access permissions for a single RTE (these
 693  *              are processed uniformly).
 694  */
 695 static bool
 696 ExecCheckRTEPermsModified(Oid relOid, Oid userid, Bitmapset *modifiedCols,
 697                                                   AclMode requiredPerms)
 698 {
 699         int                     col = -1;
 700
 701         /*
 702          * When the query doesn't explicitly update any columns, allow the query
 703          * if we have permission on any column of the rel.  This is to handle
 704          * SELECT FOR UPDATE as well as possible corner cases in UPDATE.
 705          */
 706         if (bms_is_empty(modifiedCols))
 707         {
 708                 if (pg_attribute_aclcheck_all(relOid, userid, requiredPerms,
 709                                                                           ACLMASK_ANY) != ACLCHECK_OK)
 710                         return false;
 711         }
 712
 713         while ((col = bms_next_member(modifiedCols, col)) >= 0)
 714         {
 715                 /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
 716                 AttrNumber      attno = col + FirstLowInvalidHeapAttributeNumber;
 717
 718                 if (attno == InvalidAttrNumber)
 719                 {
 720                         /* whole-row reference can't happen here */
 721                         elog(ERROR, "whole-row update is not implemented");
 722                 }
 723                 else
 724                 {
 725                         if (pg_attribute_aclcheck(relOid, attno, userid,
 726                                                                           requiredPerms) != ACLCHECK_OK)
 727                                 return false;
 728                 }
 729         }
 730         return true;
 731 }
 732
 733 /*
 734  * Check that the query does not imply any writes to non-temp tables;
 735  * unless we're in parallel mode, in which case don't even allow writes
 736  * to temp tables.
 737  *
 738  * Note: in a Hot Standby slave this would need to reject writes to temp
 739  * tables just as we do in parallel mode; but an HS slave can't have created
 740  * any temp tables in the first place, so no need to check that.
 741  */
 742 static void
 743 ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
 744 {
 745         ListCell   *l;
 746
 747         /*
 748          * Fail if write permissions are requested in parallel mode for table
 749          * (temp or non-temp), otherwise fail for any non-temp table.
 750          */
 751         foreach(l, plannedstmt->rtable)
 752         {
 753                 RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
 754
 755                 if (rte->rtekind != RTE_RELATION)
 756                         continue;
 757
 758                 if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
 759                         continue;
 760
 761                 if (isTempNamespace(get_rel_namespace(rte->relid)))
 762                         continue;
 763
 764                 PreventCommandIfReadOnly(CreateCommandTag((Node *) plannedstmt));
 765         }
 766
 767         if (plannedstmt->commandType != CMD_SELECT || plannedstmt->hasModifyingCTE)
 768                 PreventCommandIfParallelMode(CreateCommandTag((Node *) plannedstmt));
 769 }
 770
 771
 772 /* ----------------------------------------------------------------
 773  *              InitPlan
 774  *
 775  *              Initializes the query plan: open files, allocate storage
 776  *              and start up the rule manager
 777  * ----------------------------------------------------------------
 778  */
 779 static void
 780 InitPlan(QueryDesc *queryDesc, int eflags)
 781 {
 782         CmdType         operation = queryDesc->operation;
 783         PlannedStmt *plannedstmt = queryDesc->plannedstmt;
 784         Plan       *plan = plannedstmt->planTree;
 785         List       *rangeTable = plannedstmt->rtable;
 786         EState     *estate = queryDesc->estate;
 787         PlanState  *planstate;
 788         TupleDesc       tupType;
 789         ListCell   *l;
 790         int                     i;
 791
 792         /*
 793          * Do permissions checks
 794          */
 795         ExecCheckRTPerms(rangeTable, true);
 796
 797         /*
 798          * initialize the node's execution state
 799          */
 800         estate->es_range_table = rangeTable;
 801         estate->es_plannedstmt = plannedstmt;
 802
 803         /*
 804          * initialize result relation stuff, and open/lock the result rels.
 805          *
 806          * We must do this before initializing the plan tree, else we might try to
 807          * do a lock upgrade if a result rel is also a source rel.
 808          */
 809         if (plannedstmt->resultRelations)
 810         {
 811                 List       *resultRelations = plannedstmt->resultRelations;
 812                 int                     numResultRelations = list_length(resultRelations);
 813                 ResultRelInfo *resultRelInfos;
 814                 ResultRelInfo *resultRelInfo;
 815
 816                 resultRelInfos = (ResultRelInfo *)
 817                         palloc(numResultRelations * sizeof(ResultRelInfo));
 818                 resultRelInfo = resultRelInfos;
 819                 foreach(l, resultRelations)
 820                 {
 821                         Index           resultRelationIndex = lfirst_int(l);
 822                         Oid                     resultRelationOid;
 823                         Relation        resultRelation;
 824
 825                         resultRelationOid = getrelid(resultRelationIndex, rangeTable);
 826                         resultRelation = heap_open(resultRelationOid, RowExclusiveLock);
 827
 828                         InitResultRelInfo(resultRelInfo,
 829                                                           resultRelation,
 830                                                           resultRelationIndex,
 831                                                           NULL,
 832                                                           estate->es_instrument);
 833                         resultRelInfo++;
 834                 }
 835                 estate->es_result_relations = resultRelInfos;
 836                 estate->es_num_result_relations = numResultRelations;
 837                 /* es_result_relation_info is NULL except when within ModifyTable */
 838                 estate->es_result_relation_info = NULL;
 839         }
 840         else
 841         {
 842                 /*
 843                  * if no result relation, then set state appropriately
 844                  */
 845                 estate->es_result_relations = NULL;
 846                 estate->es_num_result_relations = 0;
 847                 estate->es_result_relation_info = NULL;
 848         }
 849
 850         /*
 851          * Similarly, we have to lock relations selected FOR [KEY] UPDATE/SHARE
 852          * before we initialize the plan tree, else we'd be risking lock upgrades.
 853          * While we are at it, build the ExecRowMark list.
 854          */
 855         estate->es_rowMarks = NIL;
 856         foreach(l, plannedstmt->rowMarks)
 857         {
 858                 PlanRowMark *rc = (PlanRowMark *) lfirst(l);
 859                 Oid                     relid;
 860                 Relation        relation;
 861                 ExecRowMark *erm;
 862
 863                 /* ignore "parent" rowmarks; they are irrelevant at runtime */
 864                 if (rc->isParent)
 865                         continue;
 866
 867                 /* get relation's OID (will produce InvalidOid if subquery) */
 868                 relid = getrelid(rc->rti, rangeTable);
 869
 870                 /*
 871                  * If you change the conditions under which rel locks are acquired
 872                  * here, be sure to adjust ExecOpenScanRelation to match.
 873                  */
 874                 switch (rc->markType)
 875                 {
 876                         case ROW_MARK_EXCLUSIVE:
 877                         case ROW_MARK_NOKEYEXCLUSIVE:
 878                         case ROW_MARK_SHARE:
 879                         case ROW_MARK_KEYSHARE:
 880                                 relation = heap_open(relid, RowShareLock);
 881                                 break;
 882                         case ROW_MARK_REFERENCE:
 883                                 relation = heap_open(relid, AccessShareLock);
 884                                 break;
 885                         case ROW_MARK_COPY:
 886                                 /* no physical table access is required */
 887                                 relation = NULL;
 888                                 break;
 889                         default:
 890                                 elog(ERROR, "unrecognized markType: %d", rc->markType);
 891                                 relation = NULL;        /* keep compiler quiet */
 892                                 break;
 893                 }
 894
 895                 /* Check that relation is a legal target for marking */
 896                 if (relation)
 897                         CheckValidRowMarkRel(relation, rc->markType);
 898
 899                 erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
 900                 erm->relation = relation;
 901                 erm->relid = relid;
 902                 erm->rti = rc->rti;
 903                 erm->prti = rc->prti;
 904                 erm->rowmarkId = rc->rowmarkId;
 905                 erm->markType = rc->markType;
 906                 erm->strength = rc->strength;
 907                 erm->waitPolicy = rc->waitPolicy;
 908                 erm->ermActive = false;
 909                 ItemPointerSetInvalid(&(erm->curCtid));
 910                 erm->ermExtra = NULL;
 911                 estate->es_rowMarks = lappend(estate->es_rowMarks, erm);
 912         }
 913
 914         /*
 915          * Initialize the executor's tuple table to empty.
 916          */
 917         estate->es_tupleTable = NIL;
 918         estate->es_trig_tuple_slot = NULL;
 919         estate->es_trig_oldtup_slot = NULL;
 920         estate->es_trig_newtup_slot = NULL;
 921
 922         /* mark EvalPlanQual not active */
 923         estate->es_epqTuple = NULL;
 924         estate->es_epqTupleSet = NULL;
 925         estate->es_epqScanDone = NULL;
 926
 927         /*
 928          * Initialize private state information for each SubPlan.  We must do this
 929          * before running ExecInitNode on the main query tree, since
 930          * ExecInitSubPlan expects to be able to find these entries.
 931          */
 932         Assert(estate->es_subplanstates == NIL);
 933         i = 1;                                          /* subplan indices count from 1 */
 934         foreach(l, plannedstmt->subplans)
 935         {
 936                 Plan       *subplan = (Plan *) lfirst(l);
 937                 PlanState  *subplanstate;
 938                 int                     sp_eflags;
 939
 940                 /*
 941                  * A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
 942                  * it is a parameterless subplan (not initplan), we suggest that it be
 943                  * prepared to handle REWIND efficiently; otherwise there is no need.
 944                  */
 945                 sp_eflags = eflags
 946                         & (EXEC_FLAG_EXPLAIN_ONLY | EXEC_FLAG_WITH_NO_DATA);
 947                 if (bms_is_member(i, plannedstmt->rewindPlanIDs))
 948                         sp_eflags |= EXEC_FLAG_REWIND;
 949
 950                 subplanstate = ExecInitNode(subplan, estate, sp_eflags);
 951
 952                 estate->es_subplanstates = lappend(estate->es_subplanstates,
 953                                                                                    subplanstate);
 954
 955                 i++;
 956         }
 957
 958         /*
 959          * Initialize the private state information for all the nodes in the query
 960          * tree.  This opens files, allocates storage and leaves us ready to start
 961          * processing tuples.
 962          */
 963         planstate = ExecInitNode(plan, estate, eflags);
 964
 965         /*
 966          * Get the tuple descriptor describing the type of tuples to return.
 967          */
 968         tupType = ExecGetResultType(planstate);
 969
 970         /*
 971          * Initialize the junk filter if needed.  SELECT queries need a filter if
 972          * there are any junk attrs in the top-level tlist.
 973          */
 974         if (operation == CMD_SELECT)
 975         {
 976                 bool            junk_filter_needed = false;
 977                 ListCell   *tlist;
 978
 979                 foreach(tlist, plan->targetlist)
 980                 {
 981                         TargetEntry *tle = (TargetEntry *) lfirst(tlist);
 982
 983                         if (tle->resjunk)
 984                         {
 985                                 junk_filter_needed = true;
 986                                 break;
 987                         }
 988                 }
 989
 990                 if (junk_filter_needed)
 991                 {
 992                         JunkFilter *j;
 993
 994                         j = ExecInitJunkFilter(planstate->plan->targetlist,
 995                                                                    tupType->tdhasoid,
 996                                                                    ExecInitExtraTupleSlot(estate));
 997                         estate->es_junkFilter = j;
 998
 999                         /* Want to return the cleaned tuple type */
1000                         tupType = j->jf_cleanTupType;
1001                 }
1002         }
1003
1004         queryDesc->tupDesc = tupType;
1005         queryDesc->planstate = planstate;
1006 }
1007
1008 /*
1009  * Check that a proposed result relation is a legal target for the operation
1010  *
1011  * Generally the parser and/or planner should have noticed any such mistake
1012  * already, but let's make sure.
1013  *
1014  * Note: when changing this function, you probably also need to look at
1015  * CheckValidRowMarkRel.
1016  */
1017 void
1018 CheckValidResultRel(Relation resultRel, CmdType operation)
1019 {
1020         TriggerDesc *trigDesc = resultRel->trigdesc;
1021         FdwRoutine *fdwroutine;
1022
1023         switch (resultRel->rd_rel->relkind)
1024         {
1025                 case RELKIND_RELATION:
1026                 case RELKIND_PARTITIONED_TABLE:
1027                         /* OK */
1028                         break;
1029                 case RELKIND_SEQUENCE:
1030                         ereport(ERROR,
1031                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1032                                          errmsg("cannot change sequence \"%s\"",
1033                                                         RelationGetRelationName(resultRel))));
1034                         break;
1035                 case RELKIND_TOASTVALUE:
1036                         ereport(ERROR,
1037                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1038                                          errmsg("cannot change TOAST relation \"%s\"",
1039                                                         RelationGetRelationName(resultRel))));
1040                         break;
1041                 case RELKIND_VIEW:
1042
1043                         /*
1044                          * Okay only if there's a suitable INSTEAD OF trigger.  Messages
1045                          * here should match rewriteHandler.c's rewriteTargetView, except
1046                          * that we omit errdetail because we haven't got the information
1047                          * handy (and given that we really shouldn't get here anyway, it's
1048                          * not worth great exertion to get).
1049                          */
1050                         switch (operation)
1051                         {
1052                                 case CMD_INSERT:
1053                                         if (!trigDesc || !trigDesc->trig_insert_instead_row)
1054                                                 ereport(ERROR,
1055                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1056                                                    errmsg("cannot insert into view \"%s\"",
1057                                                                   RelationGetRelationName(resultRel)),
1058                                                    errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
1059                                         break;
1060                                 case CMD_UPDATE:
1061                                         if (!trigDesc || !trigDesc->trig_update_instead_row)
1062                                                 ereport(ERROR,
1063                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1064                                                    errmsg("cannot update view \"%s\"",
1065                                                                   RelationGetRelationName(resultRel)),
1066                                                    errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
1067                                         break;
1068                                 case CMD_DELETE:
1069                                         if (!trigDesc || !trigDesc->trig_delete_instead_row)
1070                                                 ereport(ERROR,
1071                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1072                                                    errmsg("cannot delete from view \"%s\"",
1073                                                                   RelationGetRelationName(resultRel)),
1074                                                    errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
1075                                         break;
1076                                 default:
1077                                         elog(ERROR, "unrecognized CmdType: %d", (int) operation);
1078                                         break;
1079                         }
1080                         break;
1081                 case RELKIND_MATVIEW:
1082                         if (!MatViewIncrementalMaintenanceIsEnabled())
1083                                 ereport(ERROR,
1084                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1085                                                  errmsg("cannot change materialized view \"%s\"",
1086                                                                 RelationGetRelationName(resultRel))));
1087                         break;
1088                 case RELKIND_FOREIGN_TABLE:
1089                         /* Okay only if the FDW supports it */
1090                         fdwroutine = GetFdwRoutineForRelation(resultRel, false);
1091                         switch (operation)
1092                         {
1093                                 case CMD_INSERT:
1094                                         if (fdwroutine->ExecForeignInsert == NULL)
1095                                                 ereport(ERROR,
1096                                                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1097                                                         errmsg("cannot insert into foreign table \"%s\"",
1098                                                                    RelationGetRelationName(resultRel))));
1099                                         if (fdwroutine->IsForeignRelUpdatable != NULL &&
1100                                                 (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_INSERT)) == 0)
1101                                                 ereport(ERROR,
1102                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1103                                                 errmsg("foreign table \"%s\" does not allow inserts",
1104                                                            RelationGetRelationName(resultRel))));
1105                                         break;
1106                                 case CMD_UPDATE:
1107                                         if (fdwroutine->ExecForeignUpdate == NULL)
1108                                                 ereport(ERROR,
1109                                                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1110                                                                  errmsg("cannot update foreign table \"%s\"",
1111                                                                                 RelationGetRelationName(resultRel))));
1112                                         if (fdwroutine->IsForeignRelUpdatable != NULL &&
1113                                                 (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_UPDATE)) == 0)
1114                                                 ereport(ERROR,
1115                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1116                                                 errmsg("foreign table \"%s\" does not allow updates",
1117                                                            RelationGetRelationName(resultRel))));
1118                                         break;
1119                                 case CMD_DELETE:
1120                                         if (fdwroutine->ExecForeignDelete == NULL)
1121                                                 ereport(ERROR,
1122                                                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1123                                                         errmsg("cannot delete from foreign table \"%s\"",
1124                                                                    RelationGetRelationName(resultRel))));
1125                                         if (fdwroutine->IsForeignRelUpdatable != NULL &&
1126                                                 (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_DELETE)) == 0)
1127                                                 ereport(ERROR,
1128                                                   (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1129                                                 errmsg("foreign table \"%s\" does not allow deletes",
1130                                                            RelationGetRelationName(resultRel))));
1131                                         break;
1132                                 default:
1133                                         elog(ERROR, "unrecognized CmdType: %d", (int) operation);
1134                                         break;
1135                         }
1136                         break;
1137                 default:
1138                         ereport(ERROR,
1139                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1140                                          errmsg("cannot change relation \"%s\"",
1141                                                         RelationGetRelationName(resultRel))));
1142                         break;
1143         }
1144 }
1145
1146 /*
1147  * Check that a proposed rowmark target relation is a legal target
1148  *
1149  * In most cases parser and/or planner should have noticed this already, but
1150  * they don't cover all cases.
1151  */
1152 static void
1153 CheckValidRowMarkRel(Relation rel, RowMarkType markType)
1154 {
1155         FdwRoutine *fdwroutine;
1156
1157         switch (rel->rd_rel->relkind)
1158         {
1159                 case RELKIND_RELATION:
1160                 case RELKIND_PARTITIONED_TABLE:
1161                         /* OK */
1162                         break;
1163                 case RELKIND_SEQUENCE:
1164                         /* Must disallow this because we don't vacuum sequences */
1165                         ereport(ERROR,
1166                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1167                                          errmsg("cannot lock rows in sequence \"%s\"",
1168                                                         RelationGetRelationName(rel))));
1169                         break;
1170                 case RELKIND_TOASTVALUE:
1171                         /* We could allow this, but there seems no good reason to */
1172                         ereport(ERROR,
1173                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1174                                          errmsg("cannot lock rows in TOAST relation \"%s\"",
1175                                                         RelationGetRelationName(rel))));
1176                         break;
1177                 case RELKIND_VIEW:
1178                         /* Should not get here; planner should have expanded the view */
1179                         ereport(ERROR,
1180                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1181                                          errmsg("cannot lock rows in view \"%s\"",
1182                                                         RelationGetRelationName(rel))));
1183                         break;
1184                 case RELKIND_MATVIEW:
1185                         /* Allow referencing a matview, but not actual locking clauses */
1186                         if (markType != ROW_MARK_REFERENCE)
1187                                 ereport(ERROR,
1188                                                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1189                                            errmsg("cannot lock rows in materialized view \"%s\"",
1190                                                           RelationGetRelationName(rel))));
1191                         break;
1192                 case RELKIND_FOREIGN_TABLE:
1193                         /* Okay only if the FDW supports it */
1194                         fdwroutine = GetFdwRoutineForRelation(rel, false);
1195                         if (fdwroutine->RefetchForeignRow == NULL)
1196                                 ereport(ERROR,
1197                                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1198                                                  errmsg("cannot lock rows in foreign table \"%s\"",
1199                                                                 RelationGetRelationName(rel))));
1200                         break;
1201                 default:
1202                         ereport(ERROR,
1203                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1204                                          errmsg("cannot lock rows in relation \"%s\"",
1205                                                         RelationGetRelationName(rel))));
1206                         break;
1207         }
1208 }
1209
1210 /*
1211  * Initialize ResultRelInfo data for one result relation
1212  *
1213  * Caution: before Postgres 9.1, this function included the relkind checking
1214  * that's now in CheckValidResultRel, and it also did ExecOpenIndices if
1215  * appropriate.  Be sure callers cover those needs.
1216  */
1217 void
1218 InitResultRelInfo(ResultRelInfo *resultRelInfo,
1219                                   Relation resultRelationDesc,
1220                                   Index resultRelationIndex,
1221                                   Relation partition_root,
1222                                   int instrument_options)
1223 {
1224         List   *partition_check = NIL;
1225
1226         MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
1227         resultRelInfo->type = T_ResultRelInfo;
1228         resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
1229         resultRelInfo->ri_RelationDesc = resultRelationDesc;
1230         resultRelInfo->ri_NumIndices = 0;
1231         resultRelInfo->ri_IndexRelationDescs = NULL;
1232         resultRelInfo->ri_IndexRelationInfo = NULL;
1233         /* make a copy so as not to depend on relcache info not changing... */
1234         resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
1235         if (resultRelInfo->ri_TrigDesc)
1236         {
1237                 int                     n = resultRelInfo->ri_TrigDesc->numtriggers;
1238
1239                 resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
1240                         palloc0(n * sizeof(FmgrInfo));
1241                 resultRelInfo->ri_TrigWhenExprs = (List **)
1242                         palloc0(n * sizeof(List *));
1243                 if (instrument_options)
1244                         resultRelInfo->ri_TrigInstrument = InstrAlloc(n, instrument_options);
1245         }
1246         else
1247         {
1248                 resultRelInfo->ri_TrigFunctions = NULL;
1249                 resultRelInfo->ri_TrigWhenExprs = NULL;
1250                 resultRelInfo->ri_TrigInstrument = NULL;
1251         }
1252         if (resultRelationDesc->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
1253                 resultRelInfo->ri_FdwRoutine = GetFdwRoutineForRelation(resultRelationDesc, true);
1254         else
1255                 resultRelInfo->ri_FdwRoutine = NULL;
1256         resultRelInfo->ri_FdwState = NULL;
1257         resultRelInfo->ri_usesFdwDirectModify = false;
1258         resultRelInfo->ri_ConstraintExprs = NULL;
1259         resultRelInfo->ri_junkFilter = NULL;
1260         resultRelInfo->ri_projectReturning = NULL;
1261
1262         /*
1263          * If partition_root has been specified, that means we are builiding the
1264          * ResultRelationInfo for one of its leaf partitions.  In that case, we
1265          * need *not* initialize the leaf partition's constraint, but rather the
1266          * the partition_root's (if any).  We must do that explicitly like this,
1267          * because implicit partition constraints are not inherited like user-
1268          * defined constraints and would fail to be enforced by ExecConstraints()
1269          * after a tuple is routed to a leaf partition.
1270          */
1271         if (partition_root)
1272         {
1273                 /*
1274                  * Root table itself may or may not be a partition; partition_check
1275                  * would be NIL in the latter case.
1276                  */
1277                 partition_check = RelationGetPartitionQual(partition_root);
1278
1279                 /*
1280                  * This is not our own partition constraint, but rather an ancestor's.
1281                  * So any Vars in it bear the ancestor's attribute numbers.  We must
1282                  * switch them to our own.
1283                  */
1284                 if (partition_check != NIL)
1285                         partition_check = map_partition_varattnos(partition_check,
1286                                                                                                           resultRelationDesc,
1287                                                                                                           partition_root);
1288         }
1289         else
1290                 partition_check = RelationGetPartitionQual(resultRelationDesc);
1291
1292         resultRelInfo->ri_PartitionCheck = partition_check;
1293         resultRelInfo->ri_PartitionRoot = partition_root;
1294 }
1295
1296 /*
1297  *              ExecGetTriggerResultRel
1298  *
1299  * Get a ResultRelInfo for a trigger target relation.  Most of the time,
1300  * triggers are fired on one of the result relations of the query, and so
1301  * we can just return a member of the es_result_relations array.  (Note: in
1302  * self-join situations there might be multiple members with the same OID;
1303  * if so it doesn't matter which one we pick.)  However, it is sometimes
1304  * necessary to fire triggers on other relations; this happens mainly when an
1305  * RI update trigger queues additional triggers on other relations, which will
1306  * be processed in the context of the outer query.  For efficiency's sake,
1307  * we want to have a ResultRelInfo for those triggers too; that can avoid
1308  * repeated re-opening of the relation.  (It also provides a way for EXPLAIN
1309  * ANALYZE to report the runtimes of such triggers.)  So we make additional
1310  * ResultRelInfo's as needed, and save them in es_trig_target_relations.
1311  */
1312 ResultRelInfo *
1313 ExecGetTriggerResultRel(EState *estate, Oid relid)
1314 {
1315         ResultRelInfo *rInfo;
1316         int                     nr;
1317         ListCell   *l;
1318         Relation        rel;
1319         MemoryContext oldcontext;
1320
1321         /* First, search through the query result relations */
1322         rInfo = estate->es_result_relations;
1323         nr = estate->es_num_result_relations;
1324         while (nr > 0)
1325         {
1326                 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
1327                         return rInfo;
1328                 rInfo++;
1329                 nr--;
1330         }
1331         /* Nope, but maybe we already made an extra ResultRelInfo for it */
1332         foreach(l, estate->es_trig_target_relations)
1333         {
1334                 rInfo = (ResultRelInfo *) lfirst(l);
1335                 if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
1336                         return rInfo;
1337         }
1338         /* Nope, so we need a new one */
1339
1340         /*
1341          * Open the target relation's relcache entry.  We assume that an
1342          * appropriate lock is still held by the backend from whenever the trigger
1343          * event got queued, so we need take no new lock here.  Also, we need not
1344          * recheck the relkind, so no need for CheckValidResultRel.
1345          */
1346         rel = heap_open(relid, NoLock);
1347
1348         /*
1349          * Make the new entry in the right context.
1350          */
1351         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
1352         rInfo = makeNode(ResultRelInfo);
1353         InitResultRelInfo(rInfo,
1354                                           rel,
1355                                           0,            /* dummy rangetable index */
1356                                           NULL,
1357                                           estate->es_instrument);
1358         estate->es_trig_target_relations =
1359                 lappend(estate->es_trig_target_relations, rInfo);
1360         MemoryContextSwitchTo(oldcontext);
1361
1362         /*
1363          * Currently, we don't need any index information in ResultRelInfos used
1364          * only for triggers, so no need to call ExecOpenIndices.
1365          */
1366
1367         return rInfo;
1368 }
1369
1370 /*
1371  *              ExecContextForcesOids
1372  *
1373  * This is pretty grotty: when doing INSERT, UPDATE, or CREATE TABLE AS,
1374  * we need to ensure that result tuples have space for an OID iff they are
1375  * going to be stored into a relation that has OIDs.  In other contexts
1376  * we are free to choose whether to leave space for OIDs in result tuples
1377  * (we generally don't want to, but we do if a physical-tlist optimization
1378  * is possible).  This routine checks the plan context and returns TRUE if the
1379  * choice is forced, FALSE if the choice is not forced.  In the TRUE case,
1380  * *hasoids is set to the required value.
1381  *
1382  * One reason this is ugly is that all plan nodes in the plan tree will emit
1383  * tuples with space for an OID, though we really only need the topmost node
1384  * to do so.  However, node types like Sort don't project new tuples but just
1385  * return their inputs, and in those cases the requirement propagates down
1386  * to the input node.  Eventually we might make this code smart enough to
1387  * recognize how far down the requirement really goes, but for now we just
1388  * make all plan nodes do the same thing if the top level forces the choice.
1389  *
1390  * We assume that if we are generating tuples for INSERT or UPDATE,
1391  * estate->es_result_relation_info is already set up to describe the target
1392  * relation.  Note that in an UPDATE that spans an inheritance tree, some of
1393  * the target relations may have OIDs and some not.  We have to make the
1394  * decisions on a per-relation basis as we initialize each of the subplans of
1395  * the ModifyTable node, so ModifyTable has to set es_result_relation_info
1396  * while initializing each subplan.
1397  *
1398  * CREATE TABLE AS is even uglier, because we don't have the target relation's
1399  * descriptor available when this code runs; we have to look aside at the
1400  * flags passed to ExecutorStart().
1401  */
1402 bool
1403 ExecContextForcesOids(PlanState *planstate, bool *hasoids)
1404 {
1405         ResultRelInfo *ri = planstate->state->es_result_relation_info;
1406
1407         if (ri != NULL)
1408         {
1409                 Relation        rel = ri->ri_RelationDesc;
1410
1411                 if (rel != NULL)
1412                 {
1413                         *hasoids = rel->rd_rel->relhasoids;
1414                         return true;
1415                 }
1416         }
1417
1418         if (planstate->state->es_top_eflags & EXEC_FLAG_WITH_OIDS)
1419         {
1420                 *hasoids = true;
1421                 return true;
1422         }
1423         if (planstate->state->es_top_eflags & EXEC_FLAG_WITHOUT_OIDS)
1424         {
1425                 *hasoids = false;
1426                 return true;
1427         }
1428
1429         return false;
1430 }
1431
1432 /* ----------------------------------------------------------------
1433  *              ExecPostprocessPlan
1434  *
1435  *              Give plan nodes a final chance to execute before shutdown
1436  * ----------------------------------------------------------------
1437  */
1438 static void
1439 ExecPostprocessPlan(EState *estate)
1440 {
1441         ListCell   *lc;
1442
1443         /*
1444          * Make sure nodes run forward.
1445          */
1446         estate->es_direction = ForwardScanDirection;
1447
1448         /*
1449          * Run any secondary ModifyTable nodes to completion, in case the main
1450          * query did not fetch all rows from them.  (We do this to ensure that
1451          * such nodes have predictable results.)
1452          */
1453         foreach(lc, estate->es_auxmodifytables)
1454         {
1455                 PlanState  *ps = (PlanState *) lfirst(lc);
1456
1457                 for (;;)
1458                 {
1459                         TupleTableSlot *slot;
1460
1461                         /* Reset the per-output-tuple exprcontext each time */
1462                         ResetPerTupleExprContext(estate);
1463
1464                         slot = ExecProcNode(ps);
1465
1466                         if (TupIsNull(slot))
1467                                 break;
1468                 }
1469         }
1470 }
1471
1472 /* ----------------------------------------------------------------
1473  *              ExecEndPlan
1474  *
1475  *              Cleans up the query plan -- closes files and frees up storage
1476  *
1477  * NOTE: we are no longer very worried about freeing storage per se
1478  * in this code; FreeExecutorState should be guaranteed to release all
1479  * memory that needs to be released.  What we are worried about doing
1480  * is closing relations and dropping buffer pins.  Thus, for example,
1481  * tuple tables must be cleared or dropped to ensure pins are released.
1482  * ----------------------------------------------------------------
1483  */
1484 static void
1485 ExecEndPlan(PlanState *planstate, EState *estate)
1486 {
1487         ResultRelInfo *resultRelInfo;
1488         int                     i;
1489         ListCell   *l;
1490
1491         /*
1492          * shut down the node-type-specific query processing
1493          */
1494         ExecEndNode(planstate);
1495
1496         /*
1497          * for subplans too
1498          */
1499         foreach(l, estate->es_subplanstates)
1500         {
1501                 PlanState  *subplanstate = (PlanState *) lfirst(l);
1502
1503                 ExecEndNode(subplanstate);
1504         }
1505
1506         /*
1507          * destroy the executor's tuple table.  Actually we only care about
1508          * releasing buffer pins and tupdesc refcounts; there's no need to pfree
1509          * the TupleTableSlots, since the containing memory context is about to go
1510          * away anyway.
1511          */
1512         ExecResetTupleTable(estate->es_tupleTable, false);
1513
1514         /*
1515          * close the result relation(s) if any, but hold locks until xact commit.
1516          */
1517         resultRelInfo = estate->es_result_relations;
1518         for (i = estate->es_num_result_relations; i > 0; i--)
1519         {
1520                 /* Close indices and then the relation itself */
1521                 ExecCloseIndices(resultRelInfo);
1522                 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1523                 resultRelInfo++;
1524         }
1525
1526         /*
1527          * likewise close any trigger target relations
1528          */
1529         foreach(l, estate->es_trig_target_relations)
1530         {
1531                 resultRelInfo = (ResultRelInfo *) lfirst(l);
1532                 /* Close indices and then the relation itself */
1533                 ExecCloseIndices(resultRelInfo);
1534                 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
1535         }
1536
1537         /*
1538          * close any relations selected FOR [KEY] UPDATE/SHARE, again keeping
1539          * locks
1540          */
1541         foreach(l, estate->es_rowMarks)
1542         {
1543                 ExecRowMark *erm = (ExecRowMark *) lfirst(l);
1544
1545                 if (erm->relation)
1546                         heap_close(erm->relation, NoLock);
1547         }
1548 }
1549
1550 /* ----------------------------------------------------------------
1551  *              ExecutePlan
1552  *
1553  *              Processes the query plan until we have retrieved 'numberTuples' tuples,
1554  *              moving in the specified direction.
1555  *
1556  *              Runs to completion if numberTuples is 0
1557  *
1558  * Note: the ctid attribute is a 'junk' attribute that is removed before the
1559  * user can see it
1560  * ----------------------------------------------------------------
1561  */
1562 static void
1563 ExecutePlan(EState *estate,
1564                         PlanState *planstate,
1565                         bool use_parallel_mode,
1566                         CmdType operation,
1567                         bool sendTuples,
1568                         uint64 numberTuples,
1569                         ScanDirection direction,
1570                         DestReceiver *dest)
1571 {
1572         TupleTableSlot *slot;
1573         uint64          current_tuple_count;
1574
1575         /*
1576          * initialize local variables
1577          */
1578         current_tuple_count = 0;
1579
1580         /*
1581          * Set the direction.
1582          */
1583         estate->es_direction = direction;
1584
1585         /*
1586          * If a tuple count was supplied, we must force the plan to run without
1587          * parallelism, because we might exit early.  Also disable parallelism
1588          * when writing into a relation, because no database changes are allowed
1589          * in parallel mode.
1590          */
1591         if (numberTuples || dest->mydest == DestIntoRel)
1592                 use_parallel_mode = false;
1593
1594         /*
1595          * If a tuple count was supplied, we must force the plan to run without
1596          * parallelism, because we might exit early.
1597          */
1598         if (use_parallel_mode)
1599                 EnterParallelMode();
1600
1601         /*
1602          * Loop until we've processed the proper number of tuples from the plan.
1603          */
1604         for (;;)
1605         {
1606                 /* Reset the per-output-tuple exprcontext */
1607                 ResetPerTupleExprContext(estate);
1608
1609                 /*
1610                  * Execute the plan and obtain a tuple
1611                  */
1612                 slot = ExecProcNode(planstate);
1613
1614                 /*
1615                  * if the tuple is null, then we assume there is nothing more to
1616                  * process so we just end the loop...
1617                  */
1618                 if (TupIsNull(slot))
1619                 {
1620                         /* Allow nodes to release or shut down resources. */
1621                         (void) ExecShutdownNode(planstate);
1622                         break;
1623                 }
1624
1625                 /*
1626                  * If we have a junk filter, then project a new tuple with the junk
1627                  * removed.
1628                  *
1629                  * Store this new "clean" tuple in the junkfilter's resultSlot.
1630                  * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
1631                  * because that tuple slot has the wrong descriptor.)
1632                  */
1633                 if (estate->es_junkFilter != NULL)
1634                         slot = ExecFilterJunk(estate->es_junkFilter, slot);
1635
1636                 /*
1637                  * If we are supposed to send the tuple somewhere, do so. (In
1638                  * practice, this is probably always the case at this point.)
1639                  */
1640                 if (sendTuples)
1641                 {
1642                         /*
1643                          * If we are not able to send the tuple, we assume the destination
1644                          * has closed and no more tuples can be sent. If that's the case,
1645                          * end the loop.
1646                          */
1647                         if (!((*dest->receiveSlot) (slot, dest)))
1648                                 break;
1649                 }
1650
1651                 /*
1652                  * Count tuples processed, if this is a SELECT.  (For other operation
1653                  * types, the ModifyTable plan node must count the appropriate
1654                  * events.)
1655                  */
1656                 if (operation == CMD_SELECT)
1657                         (estate->es_processed)++;
1658
1659                 /*
1660                  * check our tuple count.. if we've processed the proper number then
1661                  * quit, else loop again and process more tuples.  Zero numberTuples
1662                  * means no limit.
1663                  */
1664                 current_tuple_count++;
1665                 if (numberTuples && numberTuples == current_tuple_count)
1666                         break;
1667         }
1668
1669         if (use_parallel_mode)
1670                 ExitParallelMode();
1671 }
1672
1673
1674 /*
1675  * ExecRelCheck --- check that tuple meets constraints for result relation
1676  *
1677  * Returns NULL if OK, else name of failed check constraint
1678  */
1679 static const char *
1680 ExecRelCheck(ResultRelInfo *resultRelInfo,
1681                          TupleTableSlot *slot, EState *estate)
1682 {
1683         Relation        rel = resultRelInfo->ri_RelationDesc;
1684         int                     ncheck = rel->rd_att->constr->num_check;
1685         ConstrCheck *check = rel->rd_att->constr->check;
1686         ExprContext *econtext;
1687         MemoryContext oldContext;
1688         List       *qual;
1689         int                     i;
1690
1691         /*
1692          * If first time through for this result relation, build expression
1693          * nodetrees for rel's constraint expressions.  Keep them in the per-query
1694          * memory context so they'll survive throughout the query.
1695          */
1696         if (resultRelInfo->ri_ConstraintExprs == NULL)
1697         {
1698                 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1699                 resultRelInfo->ri_ConstraintExprs =
1700                         (List **) palloc(ncheck * sizeof(List *));
1701                 for (i = 0; i < ncheck; i++)
1702                 {
1703                         /* ExecQual wants implicit-AND form */
1704                         qual = make_ands_implicit(stringToNode(check[i].ccbin));
1705                         resultRelInfo->ri_ConstraintExprs[i] = (List *)
1706                                 ExecPrepareExpr((Expr *) qual, estate);
1707                 }
1708                 MemoryContextSwitchTo(oldContext);
1709         }
1710
1711         /*
1712          * We will use the EState's per-tuple context for evaluating constraint
1713          * expressions (creating it if it's not already there).
1714          */
1715         econtext = GetPerTupleExprContext(estate);
1716
1717         /* Arrange for econtext's scan tuple to be the tuple under test */
1718         econtext->ecxt_scantuple = slot;
1719
1720         /* And evaluate the constraints */
1721         for (i = 0; i < ncheck; i++)
1722         {
1723                 qual = resultRelInfo->ri_ConstraintExprs[i];
1724
1725                 /*
1726                  * NOTE: SQL specifies that a NULL result from a constraint expression
1727                  * is not to be treated as a failure.  Therefore, tell ExecQual to
1728                  * return TRUE for NULL.
1729                  */
1730                 if (!ExecQual(qual, econtext, true))
1731                         return check[i].ccname;
1732         }
1733
1734         /* NULL result means no error */
1735         return NULL;
1736 }
1737
1738 /*
1739  * ExecPartitionCheck --- check that tuple meets the partition constraint.
1740  *
1741  * Note: This is called *iff* resultRelInfo is the main target table.
1742  */
1743 static bool
1744 ExecPartitionCheck(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
1745                                    EState *estate)
1746 {
1747         ExprContext *econtext;
1748
1749         /*
1750          * If first time through, build expression state tree for the partition
1751          * check expression.  Keep it in the per-query memory context so they'll
1752          * survive throughout the query.
1753          */
1754         if (resultRelInfo->ri_PartitionCheckExpr == NULL)
1755         {
1756                 List *qual = resultRelInfo->ri_PartitionCheck;
1757
1758                 resultRelInfo->ri_PartitionCheckExpr = (List *)
1759                                                                         ExecPrepareExpr((Expr *) qual, estate);
1760         }
1761
1762         /*
1763          * We will use the EState's per-tuple context for evaluating constraint
1764          * expressions (creating it if it's not already there).
1765          */
1766         econtext = GetPerTupleExprContext(estate);
1767
1768         /* Arrange for econtext's scan tuple to be the tuple under test */
1769         econtext->ecxt_scantuple = slot;
1770
1771         /*
1772          * As in case of the catalogued constraints, we treat a NULL result as
1773          * success here, not a failure.
1774          */
1775         return ExecQual(resultRelInfo->ri_PartitionCheckExpr, econtext, true);
1776 }
1777
1778 /*
1779  * ExecConstraints - check constraints of the tuple in 'slot'
1780  *
1781  * This checks the traditional NOT NULL and check constraints, as well as
1782  * the partition constraint, if any.
1783  *
1784  * Note: 'slot' contains the tuple to check the constraints of, which may
1785  * have been converted from the original input tuple after tuple routing,
1786  * while 'orig_slot' contains the original tuple to be shown in the message,
1787  * if an error occurs.
1788  */
1789 void
1790 ExecConstraints(ResultRelInfo *resultRelInfo,
1791                                 TupleTableSlot *slot, TupleTableSlot *orig_slot,
1792                                 EState *estate)
1793 {
1794         Relation        rel = resultRelInfo->ri_RelationDesc;
1795         TupleDesc       tupdesc = RelationGetDescr(rel);
1796         TupleConstr *constr = tupdesc->constr;
1797         Bitmapset  *modifiedCols;
1798         Bitmapset  *insertedCols;
1799         Bitmapset  *updatedCols;
1800
1801         Assert(constr || resultRelInfo->ri_PartitionCheck);
1802
1803         if (constr && constr->has_not_null)
1804         {
1805                 int                     natts = tupdesc->natts;
1806                 int                     attrChk;
1807
1808                 for (attrChk = 1; attrChk <= natts; attrChk++)
1809                 {
1810                         if (tupdesc->attrs[attrChk - 1]->attnotnull &&
1811                                 slot_attisnull(slot, attrChk))
1812                         {
1813                                 char       *val_desc;
1814                                 Relation        orig_rel = rel;
1815                                 TupleDesc       orig_tupdesc = tupdesc;
1816
1817                                 /*
1818                                  * choose the correct relation to build val_desc from the
1819                                  * tuple contained in orig_slot
1820                                  */
1821                                 if (resultRelInfo->ri_PartitionRoot)
1822                                 {
1823                                         rel = resultRelInfo->ri_PartitionRoot;
1824                                         tupdesc = RelationGetDescr(rel);
1825                                 }
1826
1827                                 insertedCols = GetInsertedColumns(resultRelInfo, estate);
1828                                 updatedCols = GetUpdatedColumns(resultRelInfo, estate);
1829                                 modifiedCols = bms_union(insertedCols, updatedCols);
1830                                 val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
1831                                                                                                                  orig_slot,
1832                                                                                                                  tupdesc,
1833                                                                                                                  modifiedCols,
1834                                                                                                                  64);
1835
1836                                 ereport(ERROR,
1837                                                 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1838                                                  errmsg("null value in column \"%s\" violates not-null constraint",
1839                                                   NameStr(orig_tupdesc->attrs[attrChk - 1]->attname)),
1840                                                  val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
1841                                                  errtablecol(orig_rel, attrChk)));
1842                         }
1843                 }
1844         }
1845
1846         if (constr && constr->num_check > 0)
1847         {
1848                 const char *failed;
1849
1850                 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1851                 {
1852                         char       *val_desc;
1853                         Relation        orig_rel = rel;
1854
1855                         /* See the comment above. */
1856                         if (resultRelInfo->ri_PartitionRoot)
1857                         {
1858                                 rel = resultRelInfo->ri_PartitionRoot;
1859                                 tupdesc = RelationGetDescr(rel);
1860                         }
1861
1862                         insertedCols = GetInsertedColumns(resultRelInfo, estate);
1863                         updatedCols = GetUpdatedColumns(resultRelInfo, estate);
1864                         modifiedCols = bms_union(insertedCols, updatedCols);
1865                         val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
1866                                                                                                          orig_slot,
1867                                                                                                          tupdesc,
1868                                                                                                          modifiedCols,
1869                                                                                                          64);
1870                         ereport(ERROR,
1871                                         (errcode(ERRCODE_CHECK_VIOLATION),
1872                                          errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1873                                                         RelationGetRelationName(orig_rel), failed),
1874                           val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
1875                                          errtableconstraint(orig_rel, failed)));
1876                 }
1877         }
1878
1879         if (resultRelInfo->ri_PartitionCheck &&
1880                 !ExecPartitionCheck(resultRelInfo, slot, estate))
1881         {
1882                 char       *val_desc;
1883                 Relation        orig_rel = rel;
1884
1885                 /* See the comment above. */
1886                 if (resultRelInfo->ri_PartitionRoot)
1887                 {
1888                         rel = resultRelInfo->ri_PartitionRoot;
1889                         tupdesc = RelationGetDescr(rel);
1890                 }
1891
1892                 insertedCols = GetInsertedColumns(resultRelInfo, estate);
1893                 updatedCols = GetUpdatedColumns(resultRelInfo, estate);
1894                 modifiedCols = bms_union(insertedCols, updatedCols);
1895                 val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
1896                                                                                                  orig_slot,
1897                                                                                                  tupdesc,
1898                                                                                                  modifiedCols,
1899                                                                                                  64);
1900                 ereport(ERROR,
1901                                 (errcode(ERRCODE_CHECK_VIOLATION),
1902                                  errmsg("new row for relation \"%s\" violates partition constraint",
1903                                                 RelationGetRelationName(orig_rel)),
1904                   val_desc ? errdetail("Failing row contains %s.", val_desc) : 0));
1905         }
1906 }
1907
1908 /*
1909  * ExecWithCheckOptions -- check that tuple satisfies any WITH CHECK OPTIONs
1910  * of the specified kind.
1911  *
1912  * Note that this needs to be called multiple times to ensure that all kinds of
1913  * WITH CHECK OPTIONs are handled (both those from views which have the WITH
1914  * CHECK OPTION set and from row level security policies).  See ExecInsert()
1915  * and ExecUpdate().
1916  */
1917 void
1918 ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
1919                                          TupleTableSlot *slot, EState *estate)
1920 {
1921         Relation        rel = resultRelInfo->ri_RelationDesc;
1922         TupleDesc       tupdesc = RelationGetDescr(rel);
1923         ExprContext *econtext;
1924         ListCell   *l1,
1925                            *l2;
1926
1927         /*
1928          * We will use the EState's per-tuple context for evaluating constraint
1929          * expressions (creating it if it's not already there).
1930          */
1931         econtext = GetPerTupleExprContext(estate);
1932
1933         /* Arrange for econtext's scan tuple to be the tuple under test */
1934         econtext->ecxt_scantuple = slot;
1935
1936         /* Check each of the constraints */
1937         forboth(l1, resultRelInfo->ri_WithCheckOptions,
1938                         l2, resultRelInfo->ri_WithCheckOptionExprs)
1939         {
1940                 WithCheckOption *wco = (WithCheckOption *) lfirst(l1);
1941                 ExprState  *wcoExpr = (ExprState *) lfirst(l2);
1942
1943                 /*
1944                  * Skip any WCOs which are not the kind we are looking for at this
1945                  * time.
1946                  */
1947                 if (wco->kind != kind)
1948                         continue;
1949
1950                 /*
1951                  * WITH CHECK OPTION checks are intended to ensure that the new tuple
1952                  * is visible (in the case of a view) or that it passes the
1953                  * 'with-check' policy (in the case of row security). If the qual
1954                  * evaluates to NULL or FALSE, then the new tuple won't be included in
1955                  * the view or doesn't pass the 'with-check' policy for the table.  We
1956                  * need ExecQual to return FALSE for NULL to handle the view case (the
1957                  * opposite of what we do above for CHECK constraints).
1958                  */
1959                 if (!ExecQual((List *) wcoExpr, econtext, false))
1960                 {
1961                         char       *val_desc;
1962                         Bitmapset  *modifiedCols;
1963                         Bitmapset  *insertedCols;
1964                         Bitmapset  *updatedCols;
1965
1966                         switch (wco->kind)
1967                         {
1968                                         /*
1969                                          * For WITH CHECK OPTIONs coming from views, we might be
1970                                          * able to provide the details on the row, depending on
1971                                          * the permissions on the relation (that is, if the user
1972                                          * could view it directly anyway).  For RLS violations, we
1973                                          * don't include the data since we don't know if the user
1974                                          * should be able to view the tuple as as that depends on
1975                                          * the USING policy.
1976                                          */
1977                                 case WCO_VIEW_CHECK:
1978                                         insertedCols = GetInsertedColumns(resultRelInfo, estate);
1979                                         updatedCols = GetUpdatedColumns(resultRelInfo, estate);
1980                                         modifiedCols = bms_union(insertedCols, updatedCols);
1981                                         val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
1982                                                                                                                          slot,
1983                                                                                                                          tupdesc,
1984                                                                                                                          modifiedCols,
1985                                                                                                                          64);
1986
1987                                         ereport(ERROR,
1988                                                         (errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
1989                                           errmsg("new row violates check option for view \"%s\"",
1990                                                          wco->relname),
1991                                                          val_desc ? errdetail("Failing row contains %s.",
1992                                                                                                   val_desc) : 0));
1993                                         break;
1994                                 case WCO_RLS_INSERT_CHECK:
1995                                 case WCO_RLS_UPDATE_CHECK:
1996                                         if (wco->polname != NULL)
1997                                                 ereport(ERROR,
1998                                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
1999                                                                  errmsg("new row violates row-level security policy \"%s\" for table \"%s\"",
2000                                                                                 wco->polname, wco->relname)));
2001                                         else
2002                                                 ereport(ERROR,
2003                                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
2004                                                                  errmsg("new row violates row-level security policy for table \"%s\"",
2005                                                                                 wco->relname)));
2006                                         break;
2007                                 case WCO_RLS_CONFLICT_CHECK:
2008                                         if (wco->polname != NULL)
2009                                                 ereport(ERROR,
2010                                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
2011                                                                  errmsg("new row violates row-level security policy \"%s\" (USING expression) for table \"%s\"",
2012                                                                                 wco->polname, wco->relname)));
2013                                         else
2014                                                 ereport(ERROR,
2015                                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
2016                                                                  errmsg("new row violates row-level security policy (USING expression) for table \"%s\"",
2017                                                                                 wco->relname)));
2018                                         break;
2019                                 default:
2020                                         elog(ERROR, "unrecognized WCO kind: %u", wco->kind);
2021                                         break;
2022                         }
2023                 }
2024         }
2025 }
2026
2027 /*
2028  * ExecBuildSlotValueDescription -- construct a string representing a tuple
2029  *
2030  * This is intentionally very similar to BuildIndexValueDescription, but
2031  * unlike that function, we truncate long field values (to at most maxfieldlen
2032  * bytes).  That seems necessary here since heap field values could be very
2033  * long, whereas index entries typically aren't so wide.
2034  *
2035  * Also, unlike the case with index entries, we need to be prepared to ignore
2036  * dropped columns.  We used to use the slot's tuple descriptor to decode the
2037  * data, but the slot's descriptor doesn't identify dropped columns, so we
2038  * now need to be passed the relation's descriptor.
2039  *
2040  * Note that, like BuildIndexValueDescription, if the user does not have
2041  * permission to view any of the columns involved, a NULL is returned.  Unlike
2042  * BuildIndexValueDescription, if the user has access to view a subset of the
2043  * column involved, that subset will be returned with a key identifying which
2044  * columns they are.
2045  */
2046 static char *
2047 ExecBuildSlotValueDescription(Oid reloid,
2048                                                           TupleTableSlot *slot,
2049                                                           TupleDesc tupdesc,
2050                                                           Bitmapset *modifiedCols,
2051                                                           int maxfieldlen)
2052 {
2053         StringInfoData buf;
2054         StringInfoData collist;
2055         bool            write_comma = false;
2056         bool            write_comma_collist = false;
2057         int                     i;
2058         AclResult       aclresult;
2059         bool            table_perm = false;
2060         bool            any_perm = false;
2061
2062         /*
2063          * Check if RLS is enabled and should be active for the relation; if so,
2064          * then don't return anything.  Otherwise, go through normal permission
2065          * checks.
2066          */
2067         if (check_enable_rls(reloid, InvalidOid, true) == RLS_ENABLED)
2068                 return NULL;
2069
2070         initStringInfo(&buf);
2071
2072         appendStringInfoChar(&buf, '(');
2073
2074         /*
2075          * Check if the user has permissions to see the row.  Table-level SELECT
2076          * allows access to all columns.  If the user does not have table-level
2077          * SELECT then we check each column and include those the user has SELECT
2078          * rights on.  Additionally, we always include columns the user provided
2079          * data for.
2080          */
2081         aclresult = pg_class_aclcheck(reloid, GetUserId(), ACL_SELECT);
2082         if (aclresult != ACLCHECK_OK)
2083         {
2084                 /* Set up the buffer for the column list */
2085                 initStringInfo(&collist);
2086                 appendStringInfoChar(&collist, '(');
2087         }
2088         else
2089                 table_perm = any_perm = true;
2090
2091         /* Make sure the tuple is fully deconstructed */
2092         slot_getallattrs(slot);
2093
2094         for (i = 0; i < tupdesc->natts; i++)
2095         {
2096                 bool            column_perm = false;
2097                 char       *val;
2098                 int                     vallen;
2099
2100                 /* ignore dropped columns */
2101                 if (tupdesc->attrs[i]->attisdropped)
2102                         continue;
2103
2104                 if (!table_perm)
2105                 {
2106                         /*
2107                          * No table-level SELECT, so need to make sure they either have
2108                          * SELECT rights on the column or that they have provided the data
2109                          * for the column.  If not, omit this column from the error
2110                          * message.
2111                          */
2112                         aclresult = pg_attribute_aclcheck(reloid, tupdesc->attrs[i]->attnum,
2113                                                                                           GetUserId(), ACL_SELECT);
2114                         if (bms_is_member(tupdesc->attrs[i]->attnum - FirstLowInvalidHeapAttributeNumber,
2115                                                           modifiedCols) || aclresult == ACLCHECK_OK)
2116                         {
2117                                 column_perm = any_perm = true;
2118
2119                                 if (write_comma_collist)
2120                                         appendStringInfoString(&collist, ", ");
2121                                 else
2122                                         write_comma_collist = true;
2123
2124                                 appendStringInfoString(&collist, NameStr(tupdesc->attrs[i]->attname));
2125                         }
2126                 }
2127
2128                 if (table_perm || column_perm)
2129                 {
2130                         if (slot->tts_isnull[i])
2131                                 val = "null";
2132                         else
2133                         {
2134                                 Oid                     foutoid;
2135                                 bool            typisvarlena;
2136
2137                                 getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
2138                                                                   &foutoid, &typisvarlena);
2139                                 val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
2140                         }
2141
2142                         if (write_comma)
2143                                 appendStringInfoString(&buf, ", ");
2144                         else
2145                                 write_comma = true;
2146
2147                         /* truncate if needed */
2148                         vallen = strlen(val);
2149                         if (vallen <= maxfieldlen)
2150                                 appendStringInfoString(&buf, val);
2151                         else
2152                         {
2153                                 vallen = pg_mbcliplen(val, vallen, maxfieldlen);
2154                                 appendBinaryStringInfo(&buf, val, vallen);
2155                                 appendStringInfoString(&buf, "...");
2156                         }
2157                 }
2158         }
2159
2160         /* If we end up with zero columns being returned, then return NULL. */
2161         if (!any_perm)
2162                 return NULL;
2163
2164         appendStringInfoChar(&buf, ')');
2165
2166         if (!table_perm)
2167         {
2168                 appendStringInfoString(&collist, ") = ");
2169                 appendStringInfoString(&collist, buf.data);
2170
2171                 return collist.data;
2172         }
2173
2174         return buf.data;
2175 }
2176
2177
2178 /*
2179  * ExecUpdateLockMode -- find the appropriate UPDATE tuple lock mode for a
2180  * given ResultRelInfo
2181  */
2182 LockTupleMode
2183 ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo)
2184 {
2185         Bitmapset  *keyCols;
2186         Bitmapset  *updatedCols;
2187
2188         /*
2189          * Compute lock mode to use.  If columns that are part of the key have not
2190          * been modified, then we can use a weaker lock, allowing for better
2191          * concurrency.
2192          */
2193         updatedCols = GetUpdatedColumns(relinfo, estate);
2194         keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc,
2195                                                                                  INDEX_ATTR_BITMAP_KEY);
2196
2197         if (bms_overlap(keyCols, updatedCols))
2198                 return LockTupleExclusive;
2199
2200         return LockTupleNoKeyExclusive;
2201 }
2202
2203 /*
2204  * ExecFindRowMark -- find the ExecRowMark struct for given rangetable index
2205  *
2206  * If no such struct, either return NULL or throw error depending on missing_ok
2207  */
2208 ExecRowMark *
2209 ExecFindRowMark(EState *estate, Index rti, bool missing_ok)
2210 {
2211         ListCell   *lc;
2212
2213         foreach(lc, estate->es_rowMarks)
2214         {
2215                 ExecRowMark *erm = (ExecRowMark *) lfirst(lc);
2216
2217                 if (erm->rti == rti)
2218                         return erm;
2219         }
2220         if (!missing_ok)
2221                 elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
2222         return NULL;
2223 }
2224
2225 /*
2226  * ExecBuildAuxRowMark -- create an ExecAuxRowMark struct
2227  *
2228  * Inputs are the underlying ExecRowMark struct and the targetlist of the
2229  * input plan node (not planstate node!).  We need the latter to find out
2230  * the column numbers of the resjunk columns.
2231  */
2232 ExecAuxRowMark *
2233 ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
2234 {
2235         ExecAuxRowMark *aerm = (ExecAuxRowMark *) palloc0(sizeof(ExecAuxRowMark));
2236         char            resname[32];
2237
2238         aerm->rowmark = erm;
2239
2240         /* Look up the resjunk columns associated with this rowmark */
2241         if (erm->markType != ROW_MARK_COPY)
2242         {
2243                 /* need ctid for all methods other than COPY */
2244                 snprintf(resname, sizeof(resname), "ctid%u", erm->rowmarkId);
2245                 aerm->ctidAttNo = ExecFindJunkAttributeInTlist(targetlist,
2246                                                                                                            resname);
2247                 if (!AttributeNumberIsValid(aerm->ctidAttNo))
2248                         elog(ERROR, "could not find junk %s column", resname);
2249         }
2250         else
2251         {
2252                 /* need wholerow if COPY */
2253                 snprintf(resname, sizeof(resname), "wholerow%u", erm->rowmarkId);
2254                 aerm->wholeAttNo = ExecFindJunkAttributeInTlist(targetlist,
2255                                                                                                                 resname);
2256                 if (!AttributeNumberIsValid(aerm->wholeAttNo))
2257                         elog(ERROR, "could not find junk %s column", resname);
2258         }
2259
2260         /* if child rel, need tableoid */
2261         if (erm->rti != erm->prti)
2262         {
2263                 snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
2264                 aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
2265                                                                                                            resname);
2266                 if (!AttributeNumberIsValid(aerm->toidAttNo))
2267                         elog(ERROR, "could not find junk %s column", resname);
2268         }
2269
2270         return aerm;
2271 }
2272
2273
2274 /*
2275  * EvalPlanQual logic --- recheck modified tuple(s) to see if we want to
2276  * process the updated version under READ COMMITTED rules.
2277  *
2278  * See backend/executor/README for some info about how this works.
2279  */
2280
2281
2282 /*
2283  * Check a modified tuple to see if we want to process its updated version
2284  * under READ COMMITTED rules.
2285  *
2286  *      estate - outer executor state data
2287  *      epqstate - state for EvalPlanQual rechecking
2288  *      relation - table containing tuple
2289  *      rti - rangetable index of table containing tuple
2290  *      lockmode - requested tuple lock mode
2291  *      *tid - t_ctid from the outdated tuple (ie, next updated version)
2292  *      priorXmax - t_xmax from the outdated tuple
2293  *
2294  * *tid is also an output parameter: it's modified to hold the TID of the
2295  * latest version of the tuple (note this may be changed even on failure)
2296  *
2297  * Returns a slot containing the new candidate update/delete tuple, or
2298  * NULL if we determine we shouldn't process the row.
2299  *
2300  * Note: properly, lockmode should be declared as enum LockTupleMode,
2301  * but we use "int" to avoid having to include heapam.h in executor.h.
2302  */
2303 TupleTableSlot *
2304 EvalPlanQual(EState *estate, EPQState *epqstate,
2305                          Relation relation, Index rti, int lockmode,
2306                          ItemPointer tid, TransactionId priorXmax)
2307 {
2308         TupleTableSlot *slot;
2309         HeapTuple       copyTuple;
2310
2311         Assert(rti > 0);
2312
2313         /*
2314          * Get and lock the updated version of the row; if fail, return NULL.
2315          */
2316         copyTuple = EvalPlanQualFetch(estate, relation, lockmode, LockWaitBlock,
2317                                                                   tid, priorXmax);
2318
2319         if (copyTuple == NULL)
2320                 return NULL;
2321
2322         /*
2323          * For UPDATE/DELETE we have to return tid of actual row we're executing
2324          * PQ for.
2325          */
2326         *tid = copyTuple->t_self;
2327
2328         /*
2329          * Need to run a recheck subquery.  Initialize or reinitialize EPQ state.
2330          */
2331         EvalPlanQualBegin(epqstate, estate);
2332
2333         /*
2334          * Free old test tuple, if any, and store new tuple where relation's scan
2335          * node will see it
2336          */
2337         EvalPlanQualSetTuple(epqstate, rti, copyTuple);
2338
2339         /*
2340          * Fetch any non-locked source rows
2341          */
2342         EvalPlanQualFetchRowMarks(epqstate);
2343
2344         /*
2345          * Run the EPQ query.  We assume it will return at most one tuple.
2346          */
2347         slot = EvalPlanQualNext(epqstate);
2348
2349         /*
2350          * If we got a tuple, force the slot to materialize the tuple so that it
2351          * is not dependent on any local state in the EPQ query (in particular,
2352          * it's highly likely that the slot contains references to any pass-by-ref
2353          * datums that may be present in copyTuple).  As with the next step, this
2354          * is to guard against early re-use of the EPQ query.
2355          */
2356         if (!TupIsNull(slot))
2357                 (void) ExecMaterializeSlot(slot);
2358
2359         /*
2360          * Clear out the test tuple.  This is needed in case the EPQ query is
2361          * re-used to test a tuple for a different relation.  (Not clear that can
2362          * really happen, but let's be safe.)
2363          */
2364         EvalPlanQualSetTuple(epqstate, rti, NULL);
2365
2366         return slot;
2367 }
2368
2369 /*
2370  * Fetch a copy of the newest version of an outdated tuple
2371  *
2372  *      estate - executor state data
2373  *      relation - table containing tuple
2374  *      lockmode - requested tuple lock mode
2375  *      wait_policy - requested lock wait policy
2376  *      *tid - t_ctid from the outdated tuple (ie, next updated version)
2377  *      priorXmax - t_xmax from the outdated tuple
2378  *
2379  * Returns a palloc'd copy of the newest tuple version, or NULL if we find
2380  * that there is no newest version (ie, the row was deleted not updated).
2381  * We also return NULL if the tuple is locked and the wait policy is to skip
2382  * such tuples.
2383  *
2384  * If successful, we have locked the newest tuple version, so caller does not
2385  * need to worry about it changing anymore.
2386  *
2387  * Note: properly, lockmode should be declared as enum LockTupleMode,
2388  * but we use "int" to avoid having to include heapam.h in executor.h.
2389  */
2390 HeapTuple
2391 EvalPlanQualFetch(EState *estate, Relation relation, int lockmode,
2392                                   LockWaitPolicy wait_policy,
2393                                   ItemPointer tid, TransactionId priorXmax)
2394 {
2395         HeapTuple       copyTuple = NULL;
2396         HeapTupleData tuple;
2397         SnapshotData SnapshotDirty;
2398
2399         /*
2400          * fetch target tuple
2401          *
2402          * Loop here to deal with updated or busy tuples
2403          */
2404         InitDirtySnapshot(SnapshotDirty);
2405         tuple.t_self = *tid;
2406         for (;;)
2407         {
2408                 Buffer          buffer;
2409
2410                 if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
2411                 {
2412                         HTSU_Result test;
2413                         HeapUpdateFailureData hufd;
2414
2415                         /*
2416                          * If xmin isn't what we're expecting, the slot must have been
2417                          * recycled and reused for an unrelated tuple.  This implies that
2418                          * the latest version of the row was deleted, so we need do
2419                          * nothing.  (Should be safe to examine xmin without getting
2420                          * buffer's content lock.  We assume reading a TransactionId to be
2421                          * atomic, and Xmin never changes in an existing tuple, except to
2422                          * invalid or frozen, and neither of those can match priorXmax.)
2423                          */
2424                         if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2425                                                                          priorXmax))
2426                         {
2427                                 ReleaseBuffer(buffer);
2428                                 return NULL;
2429                         }
2430
2431                         /* otherwise xmin should not be dirty... */
2432                         if (TransactionIdIsValid(SnapshotDirty.xmin))
2433                                 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
2434
2435                         /*
2436                          * If tuple is being updated by other transaction then we have to
2437                          * wait for its commit/abort, or die trying.
2438                          */
2439                         if (TransactionIdIsValid(SnapshotDirty.xmax))
2440                         {
2441                                 ReleaseBuffer(buffer);
2442                                 switch (wait_policy)
2443                                 {
2444                                         case LockWaitBlock:
2445                                                 XactLockTableWait(SnapshotDirty.xmax,
2446                                                                                   relation, &tuple.t_self,
2447                                                                                   XLTW_FetchUpdated);
2448                                                 break;
2449                                         case LockWaitSkip:
2450                                                 if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
2451                                                         return NULL;            /* skip instead of waiting */
2452                                                 break;
2453                                         case LockWaitError:
2454                                                 if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
2455                                                         ereport(ERROR,
2456                                                                         (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
2457                                                                          errmsg("could not obtain lock on row in relation \"%s\"",
2458                                                                                 RelationGetRelationName(relation))));
2459                                                 break;
2460                                 }
2461                                 continue;               /* loop back to repeat heap_fetch */
2462                         }
2463
2464                         /*
2465                          * If tuple was inserted by our own transaction, we have to check
2466                          * cmin against es_output_cid: cmin >= current CID means our
2467                          * command cannot see the tuple, so we should ignore it. Otherwise
2468                          * heap_lock_tuple() will throw an error, and so would any later
2469                          * attempt to update or delete the tuple.  (We need not check cmax
2470                          * because HeapTupleSatisfiesDirty will consider a tuple deleted
2471                          * by our transaction dead, regardless of cmax.) We just checked
2472                          * that priorXmax == xmin, so we can test that variable instead of
2473                          * doing HeapTupleHeaderGetXmin again.
2474                          */
2475                         if (TransactionIdIsCurrentTransactionId(priorXmax) &&
2476                                 HeapTupleHeaderGetCmin(tuple.t_data) >= estate->es_output_cid)
2477                         {
2478                                 ReleaseBuffer(buffer);
2479                                 return NULL;
2480                         }
2481
2482                         /*
2483                          * This is a live tuple, so now try to lock it.
2484                          */
2485                         test = heap_lock_tuple(relation, &tuple,
2486                                                                    estate->es_output_cid,
2487                                                                    lockmode, wait_policy,
2488                                                                    false, &buffer, &hufd);
2489                         /* We now have two pins on the buffer, get rid of one */
2490                         ReleaseBuffer(buffer);
2491
2492                         switch (test)
2493                         {
2494                                 case HeapTupleSelfUpdated:
2495
2496                                         /*
2497                                          * The target tuple was already updated or deleted by the
2498                                          * current command, or by a later command in the current
2499                                          * transaction.  We *must* ignore the tuple in the former
2500                                          * case, so as to avoid the "Halloween problem" of
2501                                          * repeated update attempts.  In the latter case it might
2502                                          * be sensible to fetch the updated tuple instead, but
2503                                          * doing so would require changing heap_update and
2504                                          * heap_delete to not complain about updating "invisible"
2505                                          * tuples, which seems pretty scary (heap_lock_tuple will
2506                                          * not complain, but few callers expect
2507                                          * HeapTupleInvisible, and we're not one of them).  So for
2508                                          * now, treat the tuple as deleted and do not process.
2509                                          */
2510                                         ReleaseBuffer(buffer);
2511                                         return NULL;
2512
2513                                 case HeapTupleMayBeUpdated:
2514                                         /* successfully locked */
2515                                         break;
2516
2517                                 case HeapTupleUpdated:
2518                                         ReleaseBuffer(buffer);
2519                                         if (IsolationUsesXactSnapshot())
2520                                                 ereport(ERROR,
2521                                                                 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
2522                                                                  errmsg("could not serialize access due to concurrent update")));
2523
2524                                         /* Should not encounter speculative tuple on recheck */
2525                                         Assert(!HeapTupleHeaderIsSpeculative(tuple.t_data));
2526                                         if (!ItemPointerEquals(&hufd.ctid, &tuple.t_self))
2527                                         {
2528                                                 /* it was updated, so look at the updated version */
2529                                                 tuple.t_self = hufd.ctid;
2530                                                 /* updated row should have xmin matching this xmax */
2531                                                 priorXmax = hufd.xmax;
2532                                                 continue;
2533                                         }
2534                                         /* tuple was deleted, so give up */
2535                                         return NULL;
2536
2537                                 case HeapTupleWouldBlock:
2538                                         ReleaseBuffer(buffer);
2539                                         return NULL;
2540
2541                                 case HeapTupleInvisible:
2542                                         elog(ERROR, "attempted to lock invisible tuple");
2543
2544                                 default:
2545                                         ReleaseBuffer(buffer);
2546                                         elog(ERROR, "unrecognized heap_lock_tuple status: %u",
2547                                                  test);
2548                                         return NULL;    /* keep compiler quiet */
2549                         }
2550
2551                         /*
2552                          * We got tuple - now copy it for use by recheck query.
2553                          */
2554                         copyTuple = heap_copytuple(&tuple);
2555                         ReleaseBuffer(buffer);
2556                         break;
2557                 }
2558
2559                 /*
2560                  * If the referenced slot was actually empty, the latest version of
2561                  * the row must have been deleted, so we need do nothing.
2562                  */
2563                 if (tuple.t_data == NULL)
2564                 {
2565                         ReleaseBuffer(buffer);
2566                         return NULL;
2567                 }
2568
2569                 /*
2570                  * As above, if xmin isn't what we're expecting, do nothing.
2571                  */
2572                 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
2573                                                                  priorXmax))
2574                 {
2575                         ReleaseBuffer(buffer);
2576                         return NULL;
2577                 }
2578
2579                 /*
2580                  * If we get here, the tuple was found but failed SnapshotDirty.
2581                  * Assuming the xmin is either a committed xact or our own xact (as it
2582                  * certainly should be if we're trying to modify the tuple), this must
2583                  * mean that the row was updated or deleted by either a committed xact
2584                  * or our own xact.  If it was deleted, we can ignore it; if it was
2585                  * updated then chain up to the next version and repeat the whole
2586                  * process.
2587                  *
2588                  * As above, it should be safe to examine xmax and t_ctid without the
2589                  * buffer content lock, because they can't be changing.
2590                  */
2591                 if (ItemPointerEquals(&tuple.t_self, &tuple.t_data->t_ctid))
2592                 {
2593                         /* deleted, so forget about it */
2594                         ReleaseBuffer(buffer);
2595                         return NULL;
2596                 }
2597
2598                 /* updated, so look at the updated row */
2599                 tuple.t_self = tuple.t_data->t_ctid;
2600                 /* updated row should have xmin matching this xmax */
2601                 priorXmax = HeapTupleHeaderGetUpdateXid(tuple.t_data);
2602                 ReleaseBuffer(buffer);
2603                 /* loop back to fetch next in chain */
2604         }
2605
2606         /*
2607          * Return the copied tuple
2608          */
2609         return copyTuple;
2610 }
2611
2612 /*
2613  * EvalPlanQualInit -- initialize during creation of a plan state node
2614  * that might need to invoke EPQ processing.
2615  *
2616  * Note: subplan/auxrowmarks can be NULL/NIL if they will be set later
2617  * with EvalPlanQualSetPlan.
2618  */
2619 void
2620 EvalPlanQualInit(EPQState *epqstate, EState *estate,
2621                                  Plan *subplan, List *auxrowmarks, int epqParam)
2622 {
2623         /* Mark the EPQ state inactive */
2624         epqstate->estate = NULL;
2625         epqstate->planstate = NULL;
2626         epqstate->origslot = NULL;
2627         /* ... and remember data that EvalPlanQualBegin will need */
2628         epqstate->plan = subplan;
2629         epqstate->arowMarks = auxrowmarks;
2630         epqstate->epqParam = epqParam;
2631 }
2632
2633 /*
2634  * EvalPlanQualSetPlan -- set or change subplan of an EPQState.
2635  *
2636  * We need this so that ModifyTable can deal with multiple subplans.
2637  */
2638 void
2639 EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan, List *auxrowmarks)
2640 {
2641         /* If we have a live EPQ query, shut it down */
2642         EvalPlanQualEnd(epqstate);
2643         /* And set/change the plan pointer */
2644         epqstate->plan = subplan;
2645         /* The rowmarks depend on the plan, too */
2646         epqstate->arowMarks = auxrowmarks;
2647 }
2648
2649 /*
2650  * Install one test tuple into EPQ state, or clear test tuple if tuple == NULL
2651  *
2652  * NB: passed tuple must be palloc'd; it may get freed later
2653  */
2654 void
2655 EvalPlanQualSetTuple(EPQState *epqstate, Index rti, HeapTuple tuple)
2656 {
2657         EState     *estate = epqstate->estate;
2658
2659         Assert(rti > 0);
2660
2661         /*
2662          * free old test tuple, if any, and store new tuple where relation's scan
2663          * node will see it
2664          */
2665         if (estate->es_epqTuple[rti - 1] != NULL)
2666                 heap_freetuple(estate->es_epqTuple[rti - 1]);
2667         estate->es_epqTuple[rti - 1] = tuple;
2668         estate->es_epqTupleSet[rti - 1] = true;
2669 }
2670
2671 /*
2672  * Fetch back the current test tuple (if any) for the specified RTI
2673  */
2674 HeapTuple
2675 EvalPlanQualGetTuple(EPQState *epqstate, Index rti)
2676 {
2677         EState     *estate = epqstate->estate;
2678
2679         Assert(rti > 0);
2680
2681         return estate->es_epqTuple[rti - 1];
2682 }
2683
2684 /*
2685  * Fetch the current row values for any non-locked relations that need
2686  * to be scanned by an EvalPlanQual operation.  origslot must have been set
2687  * to contain the current result row (top-level row) that we need to recheck.
2688  */
2689 void
2690 EvalPlanQualFetchRowMarks(EPQState *epqstate)
2691 {
2692         ListCell   *l;
2693
2694         Assert(epqstate->origslot != NULL);
2695
2696         foreach(l, epqstate->arowMarks)
2697         {
2698                 ExecAuxRowMark *aerm = (ExecAuxRowMark *) lfirst(l);
2699                 ExecRowMark *erm = aerm->rowmark;
2700                 Datum           datum;
2701                 bool            isNull;
2702                 HeapTupleData tuple;
2703
2704                 if (RowMarkRequiresRowShareLock(erm->markType))
2705                         elog(ERROR, "EvalPlanQual doesn't support locking rowmarks");
2706
2707                 /* clear any leftover test tuple for this rel */
2708                 EvalPlanQualSetTuple(epqstate, erm->rti, NULL);
2709
2710                 /* if child rel, must check whether it produced this row */
2711                 if (erm->rti != erm->prti)
2712                 {
2713                         Oid                     tableoid;
2714
2715                         datum = ExecGetJunkAttribute(epqstate->origslot,
2716                                                                                  aerm->toidAttNo,
2717                                                                                  &isNull);
2718                         /* non-locked rels could be on the inside of outer joins */
2719                         if (isNull)
2720                                 continue;
2721                         tableoid = DatumGetObjectId(datum);
2722
2723                         Assert(OidIsValid(erm->relid));
2724                         if (tableoid != erm->relid)
2725                         {
2726                                 /* this child is inactive right now */
2727                                 continue;
2728                         }
2729                 }
2730
2731                 if (erm->markType == ROW_MARK_REFERENCE)
2732                 {
2733                         HeapTuple       copyTuple;
2734
2735                         Assert(erm->relation != NULL);
2736
2737                         /* fetch the tuple's ctid */
2738                         datum = ExecGetJunkAttribute(epqstate->origslot,
2739                                                                                  aerm->ctidAttNo,
2740                                                                                  &isNull);
2741                         /* non-locked rels could be on the inside of outer joins */
2742                         if (isNull)
2743                                 continue;
2744
2745                         /* fetch requests on foreign tables must be passed to their FDW */
2746                         if (erm->relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
2747                         {
2748                                 FdwRoutine *fdwroutine;
2749                                 bool            updated = false;
2750
2751                                 fdwroutine = GetFdwRoutineForRelation(erm->relation, false);
2752                                 /* this should have been checked already, but let's be safe */
2753                                 if (fdwroutine->RefetchForeignRow == NULL)
2754                                         ereport(ERROR,
2755                                                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2756                                                    errmsg("cannot lock rows in foreign table \"%s\"",
2757                                                                   RelationGetRelationName(erm->relation))));
2758                                 copyTuple = fdwroutine->RefetchForeignRow(epqstate->estate,
2759                                                                                                                   erm,
2760                                                                                                                   datum,
2761                                                                                                                   &updated);
2762                                 if (copyTuple == NULL)
2763                                         elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
2764
2765                                 /*
2766                                  * Ideally we'd insist on updated == false here, but that
2767                                  * assumes that FDWs can track that exactly, which they might
2768                                  * not be able to.  So just ignore the flag.
2769                                  */
2770                         }
2771                         else
2772                         {
2773                                 /* ordinary table, fetch the tuple */
2774                                 Buffer          buffer;
2775
2776                                 tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
2777                                 if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
2778                                                                 false, NULL))
2779                                         elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
2780
2781                                 /* successful, copy tuple */
2782                                 copyTuple = heap_copytuple(&tuple);
2783                                 ReleaseBuffer(buffer);
2784                         }
2785
2786                         /* store tuple */
2787                         EvalPlanQualSetTuple(epqstate, erm->rti, copyTuple);
2788                 }
2789                 else
2790                 {
2791                         HeapTupleHeader td;
2792
2793                         Assert(erm->markType == ROW_MARK_COPY);
2794
2795                         /* fetch the whole-row Var for the relation */
2796                         datum = ExecGetJunkAttribute(epqstate->origslot,
2797                                                                                  aerm->wholeAttNo,
2798                                                                                  &isNull);
2799                         /* non-locked rels could be on the inside of outer joins */
2800                         if (isNull)
2801                                 continue;
2802                         td = DatumGetHeapTupleHeader(datum);
2803
2804                         /* build a temporary HeapTuple control structure */
2805                         tuple.t_len = HeapTupleHeaderGetDatumLength(td);
2806                         tuple.t_data = td;
2807                         /* relation might be a foreign table, if so provide tableoid */
2808                         tuple.t_tableOid = erm->relid;
2809                         /* also copy t_ctid in case there's valid data there */
2810                         tuple.t_self = td->t_ctid;
2811
2812                         /* copy and store tuple */
2813                         EvalPlanQualSetTuple(epqstate, erm->rti,
2814                                                                  heap_copytuple(&tuple));
2815                 }
2816         }
2817 }
2818
2819 /*
2820  * Fetch the next row (if any) from EvalPlanQual testing
2821  *
2822  * (In practice, there should never be more than one row...)
2823  */
2824 TupleTableSlot *
2825 EvalPlanQualNext(EPQState *epqstate)
2826 {
2827         MemoryContext oldcontext;
2828         TupleTableSlot *slot;
2829
2830         oldcontext = MemoryContextSwitchTo(epqstate->estate->es_query_cxt);
2831         slot = ExecProcNode(epqstate->planstate);
2832         MemoryContextSwitchTo(oldcontext);
2833
2834         return slot;
2835 }
2836
2837 /*
2838  * Initialize or reset an EvalPlanQual state tree
2839  */
2840 void
2841 EvalPlanQualBegin(EPQState *epqstate, EState *parentestate)
2842 {
2843         EState     *estate = epqstate->estate;
2844
2845         if (estate == NULL)
2846         {
2847                 /* First time through, so create a child EState */
2848                 EvalPlanQualStart(epqstate, parentestate, epqstate->plan);
2849         }
2850         else
2851         {
2852                 /*
2853                  * We already have a suitable child EPQ tree, so just reset it.
2854                  */
2855                 int                     rtsize = list_length(parentestate->es_range_table);
2856                 PlanState  *planstate = epqstate->planstate;
2857
2858                 MemSet(estate->es_epqScanDone, 0, rtsize * sizeof(bool));
2859
2860                 /* Recopy current values of parent parameters */
2861                 if (parentestate->es_plannedstmt->nParamExec > 0)
2862                 {
2863                         int                     i = parentestate->es_plannedstmt->nParamExec;
2864
2865                         while (--i >= 0)
2866                         {
2867                                 /* copy value if any, but not execPlan link */
2868                                 estate->es_param_exec_vals[i].value =
2869                                         parentestate->es_param_exec_vals[i].value;
2870                                 estate->es_param_exec_vals[i].isnull =
2871                                         parentestate->es_param_exec_vals[i].isnull;
2872                         }
2873                 }
2874
2875                 /*
2876                  * Mark child plan tree as needing rescan at all scan nodes.  The
2877                  * first ExecProcNode will take care of actually doing the rescan.
2878                  */
2879                 planstate->chgParam = bms_add_member(planstate->chgParam,
2880                                                                                          epqstate->epqParam);
2881         }
2882 }
2883
2884 /*
2885  * Start execution of an EvalPlanQual plan tree.
2886  *
2887  * This is a cut-down version of ExecutorStart(): we copy some state from
2888  * the top-level estate rather than initializing it fresh.
2889  */
2890 static void
2891 EvalPlanQualStart(EPQState *epqstate, EState *parentestate, Plan *planTree)
2892 {
2893         EState     *estate;
2894         int                     rtsize;
2895         MemoryContext oldcontext;
2896         ListCell   *l;
2897
2898         rtsize = list_length(parentestate->es_range_table);
2899
2900         epqstate->estate = estate = CreateExecutorState();
2901
2902         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
2903
2904         /*
2905          * Child EPQ EStates share the parent's copy of unchanging state such as
2906          * the snapshot, rangetable, result-rel info, and external Param info.
2907          * They need their own copies of local state, including a tuple table,
2908          * es_param_exec_vals, etc.
2909          *
2910          * The ResultRelInfo array management is trickier than it looks.  We
2911          * create a fresh array for the child but copy all the content from the
2912          * parent.  This is because it's okay for the child to share any
2913          * per-relation state the parent has already created --- but if the child
2914          * sets up any ResultRelInfo fields, such as its own junkfilter, that
2915          * state must *not* propagate back to the parent.  (For one thing, the
2916          * pointed-to data is in a memory context that won't last long enough.)
2917          */
2918         estate->es_direction = ForwardScanDirection;
2919         estate->es_snapshot = parentestate->es_snapshot;
2920         estate->es_crosscheck_snapshot = parentestate->es_crosscheck_snapshot;
2921         estate->es_range_table = parentestate->es_range_table;
2922         estate->es_plannedstmt = parentestate->es_plannedstmt;
2923         estate->es_junkFilter = parentestate->es_junkFilter;
2924         estate->es_output_cid = parentestate->es_output_cid;
2925         if (parentestate->es_num_result_relations > 0)
2926         {
2927                 int                     numResultRelations = parentestate->es_num_result_relations;
2928                 ResultRelInfo *resultRelInfos;
2929
2930                 resultRelInfos = (ResultRelInfo *)
2931                         palloc(numResultRelations * sizeof(ResultRelInfo));
2932                 memcpy(resultRelInfos, parentestate->es_result_relations,
2933                            numResultRelations * sizeof(ResultRelInfo));
2934                 estate->es_result_relations = resultRelInfos;
2935                 estate->es_num_result_relations = numResultRelations;
2936         }
2937         /* es_result_relation_info must NOT be copied */
2938         /* es_trig_target_relations must NOT be copied */
2939         estate->es_rowMarks = parentestate->es_rowMarks;
2940         estate->es_top_eflags = parentestate->es_top_eflags;
2941         estate->es_instrument = parentestate->es_instrument;
2942         /* es_auxmodifytables must NOT be copied */
2943
2944         /*
2945          * The external param list is simply shared from parent.  The internal
2946          * param workspace has to be local state, but we copy the initial values
2947          * from the parent, so as to have access to any param values that were
2948          * already set from other parts of the parent's plan tree.
2949          */
2950         estate->es_param_list_info = parentestate->es_param_list_info;
2951         if (parentestate->es_plannedstmt->nParamExec > 0)
2952         {
2953                 int                     i = parentestate->es_plannedstmt->nParamExec;
2954
2955                 estate->es_param_exec_vals = (ParamExecData *)
2956                         palloc0(i * sizeof(ParamExecData));
2957                 while (--i >= 0)
2958                 {
2959                         /* copy value if any, but not execPlan link */
2960                         estate->es_param_exec_vals[i].value =
2961                                 parentestate->es_param_exec_vals[i].value;
2962                         estate->es_param_exec_vals[i].isnull =
2963                                 parentestate->es_param_exec_vals[i].isnull;
2964                 }
2965         }
2966
2967         /*
2968          * Each EState must have its own es_epqScanDone state, but if we have
2969          * nested EPQ checks they should share es_epqTuple arrays.  This allows
2970          * sub-rechecks to inherit the values being examined by an outer recheck.
2971          */
2972         estate->es_epqScanDone = (bool *) palloc0(rtsize * sizeof(bool));
2973         if (parentestate->es_epqTuple != NULL)
2974         {
2975                 estate->es_epqTuple = parentestate->es_epqTuple;
2976                 estate->es_epqTupleSet = parentestate->es_epqTupleSet;
2977         }
2978         else
2979         {
2980                 estate->es_epqTuple = (HeapTuple *)
2981                         palloc0(rtsize * sizeof(HeapTuple));
2982                 estate->es_epqTupleSet = (bool *)
2983                         palloc0(rtsize * sizeof(bool));
2984         }
2985
2986         /*
2987          * Each estate also has its own tuple table.
2988          */
2989         estate->es_tupleTable = NIL;
2990
2991         /*
2992          * Initialize private state information for each SubPlan.  We must do this
2993          * before running ExecInitNode on the main query tree, since
2994          * ExecInitSubPlan expects to be able to find these entries. Some of the
2995          * SubPlans might not be used in the part of the plan tree we intend to
2996          * run, but since it's not easy to tell which, we just initialize them
2997          * all.
2998          */
2999         Assert(estate->es_subplanstates == NIL);
3000         foreach(l, parentestate->es_plannedstmt->subplans)
3001         {
3002                 Plan       *subplan = (Plan *) lfirst(l);
3003                 PlanState  *subplanstate;
3004
3005                 subplanstate = ExecInitNode(subplan, estate, 0);
3006                 estate->es_subplanstates = lappend(estate->es_subplanstates,
3007                                                                                    subplanstate);
3008         }
3009
3010         /*
3011          * Initialize the private state information for all the nodes in the part
3012          * of the plan tree we need to run.  This opens files, allocates storage
3013          * and leaves us ready to start processing tuples.
3014          */
3015         epqstate->planstate = ExecInitNode(planTree, estate, 0);
3016
3017         MemoryContextSwitchTo(oldcontext);
3018 }
3019
3020 /*
3021  * EvalPlanQualEnd -- shut down at termination of parent plan state node,
3022  * or if we are done with the current EPQ child.
3023  *
3024  * This is a cut-down version of ExecutorEnd(); basically we want to do most
3025  * of the normal cleanup, but *not* close result relations (which we are
3026  * just sharing from the outer query).  We do, however, have to close any
3027  * trigger target relations that got opened, since those are not shared.
3028  * (There probably shouldn't be any of the latter, but just in case...)
3029  */
3030 void
3031 EvalPlanQualEnd(EPQState *epqstate)
3032 {
3033         EState     *estate = epqstate->estate;
3034         MemoryContext oldcontext;
3035         ListCell   *l;
3036
3037         if (estate == NULL)
3038                 return;                                 /* idle, so nothing to do */
3039
3040         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
3041
3042         ExecEndNode(epqstate->planstate);
3043
3044         foreach(l, estate->es_subplanstates)
3045         {
3046                 PlanState  *subplanstate = (PlanState *) lfirst(l);
3047
3048                 ExecEndNode(subplanstate);
3049         }
3050
3051         /* throw away the per-estate tuple table */
3052         ExecResetTupleTable(estate->es_tupleTable, false);
3053
3054         /* close any trigger target relations attached to this EState */
3055         foreach(l, estate->es_trig_target_relations)
3056         {
3057                 ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
3058
3059                 /* Close indices and then the relation itself */
3060                 ExecCloseIndices(resultRelInfo);
3061                 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
3062         }
3063
3064         MemoryContextSwitchTo(oldcontext);
3065
3066         FreeExecutorState(estate);
3067
3068         /* Mark EPQState idle */
3069         epqstate->estate = NULL;
3070         epqstate->planstate = NULL;
3071         epqstate->origslot = NULL;
3072 }
3073
3074 /*
3075  * ExecSetupPartitionTupleRouting - set up information needed during
3076  * tuple routing for partitioned tables
3077  *
3078  * Output arguments:
3079  * 'pd' receives an array of PartitionDispatch objects with one entry for
3080  *              every partitioned table in the partition tree
3081  * 'partitions' receives an array of ResultRelInfo objects with one entry for
3082  *              every leaf partition in the partition tree
3083  * 'tup_conv_maps' receives an array of TupleConversionMap objects with one
3084  *              entry for every leaf partition (required to convert input tuple based
3085  *              on the root table's rowtype to a leaf partition's rowtype after tuple
3086  *              routing is done
3087  * 'partition_tuple_slot' receives a standalone TupleTableSlot to be used
3088  *              to manipulate any given leaf partition's rowtype after that partition
3089  *              is chosen by tuple-routing.
3090  * 'num_parted' receives the number of partitioned tables in the partition
3091  *              tree (= the number of entries in the 'pd' output array)
3092  * 'num_partitions' receives the number of leaf partitions in the partition
3093  *              tree (= the number of entries in the 'partitions' and 'tup_conv_maps'
3094  *              output arrays
3095  *
3096  * Note that all the relations in the partition tree are locked using the
3097  * RowExclusiveLock mode upon return from this function.
3098  */
3099 void
3100 ExecSetupPartitionTupleRouting(Relation rel,
3101                                                            PartitionDispatch **pd,
3102                                                            ResultRelInfo **partitions,
3103                                                            TupleConversionMap ***tup_conv_maps,
3104                                                            TupleTableSlot **partition_tuple_slot,
3105                                                            int *num_parted, int *num_partitions)
3106 {
3107         TupleDesc       tupDesc = RelationGetDescr(rel);
3108         List       *leaf_parts;
3109         ListCell   *cell;
3110         int                     i;
3111         ResultRelInfo *leaf_part_rri;
3112
3113         /* Get the tuple-routing information and lock partitions */
3114         *pd = RelationGetPartitionDispatchInfo(rel, RowExclusiveLock, num_parted,
3115                                                                                    &leaf_parts);
3116         *num_partitions = list_length(leaf_parts);
3117         *partitions = (ResultRelInfo *) palloc(*num_partitions *
3118                                                                                    sizeof(ResultRelInfo));
3119         *tup_conv_maps = (TupleConversionMap **) palloc0(*num_partitions *
3120                                                                                    sizeof(TupleConversionMap *));
3121
3122         /*
3123          * Initialize an empty slot that will be used to manipulate tuples of any
3124          * given partition's rowtype.  It is attached to the caller-specified node
3125          * (such as ModifyTableState) and released when the node finishes
3126          * processing.
3127          */
3128         *partition_tuple_slot = MakeTupleTableSlot();
3129
3130         leaf_part_rri = *partitions;
3131         i = 0;
3132         foreach(cell, leaf_parts)
3133         {
3134                 Relation        partrel;
3135                 TupleDesc       part_tupdesc;
3136
3137                 /*
3138                  * We locked all the partitions above including the leaf partitions.
3139                  * Note that each of the relations in *partitions are eventually
3140                  * closed by the caller.
3141                  */
3142                 partrel = heap_open(lfirst_oid(cell), NoLock);
3143                 part_tupdesc = RelationGetDescr(partrel);
3144
3145                 /*
3146                  * Verify result relation is a valid target for the current operation.
3147                  */
3148                 CheckValidResultRel(partrel, CMD_INSERT);
3149
3150                 /*
3151                  * Save a tuple conversion map to convert a tuple routed to this
3152                  * partition from the parent's type to the partition's.
3153                  */
3154                 (*tup_conv_maps)[i] = convert_tuples_by_name(tupDesc, part_tupdesc,
3155                                                                  gettext_noop("could not convert row type"));
3156
3157                 InitResultRelInfo(leaf_part_rri,
3158                                                   partrel,
3159                                                   1,     /* dummy */
3160                                                   rel,
3161                                                   0);
3162
3163                 /*
3164                  * Open partition indices (remember we do not support ON CONFLICT in
3165                  * case of partitioned tables, so we do not need support information
3166                  * for speculative insertion)
3167                  */
3168                 if (leaf_part_rri->ri_RelationDesc->rd_rel->relhasindex &&
3169                         leaf_part_rri->ri_IndexRelationDescs == NULL)
3170                         ExecOpenIndices(leaf_part_rri, false);
3171
3172                 leaf_part_rri++;
3173                 i++;
3174         }
3175 }
3176
3177 /*
3178  * ExecFindPartition -- Find a leaf partition in the partition tree rooted
3179  * at parent, for the heap tuple contained in *slot
3180  *
3181  * estate must be non-NULL; we'll need it to compute any expressions in the
3182  * partition key(s)
3183  *
3184  * If no leaf partition is found, this routine errors out with the appropriate
3185  * error message, else it returns the leaf partition sequence number returned
3186  * by get_partition_for_tuple() unchanged.
3187  */
3188 int
3189 ExecFindPartition(ResultRelInfo *resultRelInfo, PartitionDispatch *pd,
3190                                   TupleTableSlot *slot, EState *estate)
3191 {
3192         int             result;
3193         Oid             failed_at;
3194         ExprContext *econtext = GetPerTupleExprContext(estate);
3195
3196         econtext->ecxt_scantuple = slot;
3197         result = get_partition_for_tuple(pd, slot, estate, &failed_at);
3198         if (result < 0)
3199         {
3200                 Relation        rel = resultRelInfo->ri_RelationDesc;
3201                 char       *val_desc;
3202                 Bitmapset  *insertedCols,
3203                                    *updatedCols,
3204                                    *modifiedCols;
3205                 TupleDesc       tupDesc = RelationGetDescr(rel);
3206
3207                 insertedCols = GetInsertedColumns(resultRelInfo, estate);
3208                 updatedCols = GetUpdatedColumns(resultRelInfo, estate);
3209                 modifiedCols = bms_union(insertedCols, updatedCols);
3210                 val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
3211                                                                                                  slot,
3212                                                                                                  tupDesc,
3213                                                                                                  modifiedCols,
3214                                                                                                  64);
3215                 Assert(OidIsValid(failed_at));
3216                 ereport(ERROR,
3217                                 (errcode(ERRCODE_CHECK_VIOLATION),
3218                                  errmsg("no partition of relation \"%s\" found for row",
3219                                                 get_rel_name(failed_at)),
3220                   val_desc ? errdetail("Failing row contains %s.", val_desc) : 0));
3221         }
3222
3223         return result;
3224 }