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  *      ExecutorEnd()
  10  *
  11  *      The old ExecutorMain() has been replaced by ExecutorStart(),
  12  *      ExecutorRun() and ExecutorEnd()
  13  *
  14  *      These three procedures are the external interfaces to the executor.
  15  *      In each case, the query descriptor is required as an argument.
  16  *
  17  *      ExecutorStart() must be called at the beginning of execution of any
  18  *      query plan and ExecutorEnd() should always be called at the end of
  19  *      execution of a plan.
  20  *
  21  *      ExecutorRun accepts direction and count arguments that specify whether
  22  *      the plan is to be executed forwards, backwards, and for how many tuples.
  23  *
  24  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  25  * Portions Copyright (c) 1994, Regents of the University of California
  26  *
  27  *
  28  * IDENTIFICATION
  29  *        $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.227 2004/01/14 23:01:54 tgl Exp $
  30  *
  31  *-------------------------------------------------------------------------
  32  */
  33 #include "postgres.h"
  34
  35 #include "access/heapam.h"
  36 #include "catalog/heap.h"
  37 #include "catalog/namespace.h"
  38 #include "commands/tablecmds.h"
  39 #include "commands/trigger.h"
  40 #include "executor/execdebug.h"
  41 #include "executor/execdefs.h"
  42 #include "miscadmin.h"
  43 #include "optimizer/clauses.h"
  44 #include "optimizer/var.h"
  45 #include "parser/parsetree.h"
  46 #include "utils/acl.h"
  47 #include "utils/guc.h"
  48 #include "utils/lsyscache.h"
  49
  50
  51 typedef struct execRowMark
  52 {
  53         Relation        relation;
  54         Index           rti;
  55         char            resname[32];
  56 } execRowMark;
  57
  58 typedef struct evalPlanQual
  59 {
  60         Index           rti;
  61         EState     *estate;
  62         PlanState  *planstate;
  63         struct evalPlanQual *next;      /* stack of active PlanQual plans */
  64         struct evalPlanQual *free;      /* list of free PlanQual plans */
  65 } evalPlanQual;
  66
  67 /* decls for local routines only used within this module */
  68 static void InitPlan(QueryDesc *queryDesc, bool explainOnly);
  69 static void initResultRelInfo(ResultRelInfo *resultRelInfo,
  70                                   Index resultRelationIndex,
  71                                   List *rangeTable,
  72                                   CmdType operation);
  73 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
  74                         CmdType operation,
  75                         long numberTuples,
  76                         ScanDirection direction,
  77                         DestReceiver *dest);
  78 static void ExecSelect(TupleTableSlot *slot,
  79                    DestReceiver *dest,
  80                    EState *estate);
  81 static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
  82                    EState *estate);
  83 static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
  84                    EState *estate);
  85 static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
  86                    EState *estate);
  87 static TupleTableSlot *EvalPlanQualNext(EState *estate);
  88 static void EndEvalPlanQual(EState *estate);
  89 static void ExecCheckRTEPerms(RangeTblEntry *rte);
  90 static void ExecCheckXactReadOnly(Query *parsetree);
  91 static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
  92                                   evalPlanQual *priorepq);
  93 static void EvalPlanQualStop(evalPlanQual *epq);
  94
  95 /* end of local decls */
  96
  97
  98 /* ----------------------------------------------------------------
  99  *              ExecutorStart
 100  *
 101  *              This routine must be called at the beginning of any execution of any
 102  *              query plan
 103  *
 104  * Takes a QueryDesc previously created by CreateQueryDesc (it's not real
 105  * clear why we bother to separate the two functions, but...).  The tupDesc
 106  * field of the QueryDesc is filled in to describe the tuples that will be
 107  * returned, and the internal fields (estate and planstate) are set up.
 108  *
 109  * If useCurrentSnapshot is true, run the query with the latest available
 110  * snapshot, instead of the normal QuerySnapshot.  Also, if it's an update
 111  * or delete query, check that the rows to be updated or deleted would be
 112  * visible to the normal QuerySnapshot.  (This is a special-case behavior
 113  * needed for referential integrity updates in serializable transactions.
 114  * We must check all currently-committed rows, but we want to throw a
 115  * can't-serialize error if any rows that would need updates would not be
 116  * visible under the normal serializable snapshot.)
 117  *
 118  * If explainOnly is true, we are not actually intending to run the plan,
 119  * only to set up for EXPLAIN; so skip unwanted side-effects.
 120  *
 121  * NB: the CurrentMemoryContext when this is called will become the parent
 122  * of the per-query context used for this Executor invocation.
 123  * ----------------------------------------------------------------
 124  */
 125 void
 126 ExecutorStart(QueryDesc *queryDesc, bool useCurrentSnapshot, bool explainOnly)
 127 {
 128         EState     *estate;
 129         MemoryContext oldcontext;
 130
 131         /* sanity checks: queryDesc must not be started already */
 132         Assert(queryDesc != NULL);
 133         Assert(queryDesc->estate == NULL);
 134
 135         /*
 136          * If the transaction is read-only, we need to check if any writes are
 137          * planned to non-temporary tables.
 138          */
 139         if (XactReadOnly && !explainOnly)
 140                 ExecCheckXactReadOnly(queryDesc->parsetree);
 141
 142         /*
 143          * Build EState, switch into per-query memory context for startup.
 144          */
 145         estate = CreateExecutorState();
 146         queryDesc->estate = estate;
 147
 148         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 149
 150         /*
 151          * Fill in parameters, if any, from queryDesc
 152          */
 153         estate->es_param_list_info = queryDesc->params;
 154
 155         if (queryDesc->plantree->nParamExec > 0)
 156                 estate->es_param_exec_vals = (ParamExecData *)
 157                         palloc0(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
 158
 159         estate->es_instrument = queryDesc->doInstrument;
 160
 161         /*
 162          * Make our own private copy of the current query snapshot data.
 163          *
 164          * This "freezes" our idea of which tuples are good and which are not for
 165          * the life of this query, even if it outlives the current command and
 166          * current snapshot.
 167          */
 168         if (useCurrentSnapshot)
 169         {
 170                 /* RI update/delete query --- must use an up-to-date snapshot */
 171                 estate->es_snapshot = CopyCurrentSnapshot();
 172                 /* crosscheck updates/deletes against transaction snapshot */
 173                 estate->es_crosscheck_snapshot = CopyQuerySnapshot();
 174         }
 175         else
 176         {
 177                 /* normal query --- use query snapshot, no crosscheck */
 178                 estate->es_snapshot = CopyQuerySnapshot();
 179                 estate->es_crosscheck_snapshot = SnapshotAny;
 180         }
 181
 182         /*
 183          * Initialize the plan state tree
 184          */
 185         InitPlan(queryDesc, explainOnly);
 186
 187         MemoryContextSwitchTo(oldcontext);
 188 }
 189
 190 /* ----------------------------------------------------------------
 191  *              ExecutorRun
 192  *
 193  *              This is the main routine of the executor module. It accepts
 194  *              the query descriptor from the traffic cop and executes the
 195  *              query plan.
 196  *
 197  *              ExecutorStart must have been called already.
 198  *
 199  *              If direction is NoMovementScanDirection then nothing is done
 200  *              except to start up/shut down the destination.  Otherwise,
 201  *              we retrieve up to 'count' tuples in the specified direction.
 202  *
 203  *              Note: count = 0 is interpreted as no portal limit, i.e., run to
 204  *              completion.
 205  *
 206  * ----------------------------------------------------------------
 207  */
 208 TupleTableSlot *
 209 ExecutorRun(QueryDesc *queryDesc,
 210                         ScanDirection direction, long count)
 211 {
 212         EState     *estate;
 213         CmdType         operation;
 214         DestReceiver *dest;
 215         TupleTableSlot *result;
 216         MemoryContext oldcontext;
 217
 218         /* sanity checks */
 219         Assert(queryDesc != NULL);
 220
 221         estate = queryDesc->estate;
 222
 223         Assert(estate != NULL);
 224
 225         /*
 226          * Switch into per-query memory context
 227          */
 228         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 229
 230         /*
 231          * extract information from the query descriptor and the query
 232          * feature.
 233          */
 234         operation = queryDesc->operation;
 235         dest = queryDesc->dest;
 236
 237         /*
 238          * startup tuple receiver
 239          */
 240         estate->es_processed = 0;
 241         estate->es_lastoid = InvalidOid;
 242
 243         (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
 244
 245         /*
 246          * run plan
 247          */
 248         if (direction == NoMovementScanDirection)
 249                 result = NULL;
 250         else
 251                 result = ExecutePlan(estate,
 252                                                          queryDesc->planstate,
 253                                                          operation,
 254                                                          count,
 255                                                          direction,
 256                                                          dest);
 257
 258         /*
 259          * shutdown receiver
 260          */
 261         (*dest->rShutdown) (dest);
 262
 263         MemoryContextSwitchTo(oldcontext);
 264
 265         return result;
 266 }
 267
 268 /* ----------------------------------------------------------------
 269  *              ExecutorEnd
 270  *
 271  *              This routine must be called at the end of execution of any
 272  *              query plan
 273  * ----------------------------------------------------------------
 274  */
 275 void
 276 ExecutorEnd(QueryDesc *queryDesc)
 277 {
 278         EState     *estate;
 279         MemoryContext oldcontext;
 280
 281         /* sanity checks */
 282         Assert(queryDesc != NULL);
 283
 284         estate = queryDesc->estate;
 285
 286         Assert(estate != NULL);
 287
 288         /*
 289          * Switch into per-query memory context to run ExecEndPlan
 290          */
 291         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 292
 293         ExecEndPlan(queryDesc->planstate, estate);
 294
 295         /*
 296          * Must switch out of context before destroying it
 297          */
 298         MemoryContextSwitchTo(oldcontext);
 299
 300         /*
 301          * Release EState and per-query memory context.  This should release
 302          * everything the executor has allocated.
 303          */
 304         FreeExecutorState(estate);
 305
 306         /* Reset queryDesc fields that no longer point to anything */
 307         queryDesc->tupDesc = NULL;
 308         queryDesc->estate = NULL;
 309         queryDesc->planstate = NULL;
 310 }
 311
 312 /* ----------------------------------------------------------------
 313  *              ExecutorRewind
 314  *
 315  *              This routine may be called on an open queryDesc to rewind it
 316  *              to the start.
 317  * ----------------------------------------------------------------
 318  */
 319 void
 320 ExecutorRewind(QueryDesc *queryDesc)
 321 {
 322         EState     *estate;
 323         MemoryContext oldcontext;
 324
 325         /* sanity checks */
 326         Assert(queryDesc != NULL);
 327
 328         estate = queryDesc->estate;
 329
 330         Assert(estate != NULL);
 331
 332         /* It's probably not sensible to rescan updating queries */
 333         Assert(queryDesc->operation == CMD_SELECT);
 334
 335         /*
 336          * Switch into per-query memory context
 337          */
 338         oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 339
 340         /*
 341          * rescan plan
 342          */
 343         ExecReScan(queryDesc->planstate, NULL);
 344
 345         MemoryContextSwitchTo(oldcontext);
 346 }
 347
 348
 349 /*
 350  * ExecCheckRTPerms
 351  *              Check access permissions for all relations listed in a range table.
 352  */
 353 void
 354 ExecCheckRTPerms(List *rangeTable)
 355 {
 356         List       *lp;
 357
 358         foreach(lp, rangeTable)
 359         {
 360                 RangeTblEntry *rte = lfirst(lp);
 361
 362                 ExecCheckRTEPerms(rte);
 363         }
 364 }
 365
 366 /*
 367  * ExecCheckRTEPerms
 368  *              Check access permissions for a single RTE.
 369  */
 370 static void
 371 ExecCheckRTEPerms(RangeTblEntry *rte)
 372 {
 373         AclMode         requiredPerms;
 374         Oid                     relOid;
 375         AclId           userid;
 376
 377         /*
 378          * If it's a subquery, recursively examine its rangetable.
 379          */
 380         if (rte->rtekind == RTE_SUBQUERY)
 381         {
 382                 ExecCheckRTPerms(rte->subquery->rtable);
 383                 return;
 384         }
 385
 386         /*
 387          * Otherwise, only plain-relation RTEs need to be checked here.
 388          * Function RTEs are checked by init_fcache when the function is
 389          * prepared for execution. Join and special RTEs need no checks.
 390          */
 391         if (rte->rtekind != RTE_RELATION)
 392                 return;
 393
 394         /*
 395          * No work if requiredPerms is empty.
 396          */
 397         requiredPerms = rte->requiredPerms;
 398         if (requiredPerms == 0)
 399                 return;
 400
 401         relOid = rte->relid;
 402
 403         /*
 404          * userid to check as: current user unless we have a setuid
 405          * indication.
 406          *
 407          * Note: GetUserId() is presently fast enough that there's no harm in
 408          * calling it separately for each RTE.  If that stops being true, we
 409          * could call it once in ExecCheckRTPerms and pass the userid down
 410          * from there.  But for now, no need for the extra clutter.
 411          */
 412         userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
 413
 414         /*
 415          * For each bit in requiredPerms, apply the required check.  (We can't
 416          * do this in one aclcheck call because aclcheck treats multiple bits
 417          * as OR semantics, when we want AND.)
 418          *
 419          * We use a well-known cute trick for isolating the rightmost one-bit
 420          * in a nonzero word.  See nodes/bitmapset.c for commentary.
 421          */
 422 #define RIGHTMOST_ONE(x) ((int32) (x) & -((int32) (x)))
 423
 424         while (requiredPerms != 0)
 425         {
 426                 AclMode         thisPerm;
 427                 AclResult       aclcheck_result;
 428
 429                 thisPerm = RIGHTMOST_ONE(requiredPerms);
 430                 requiredPerms &= ~thisPerm;
 431
 432                 aclcheck_result = pg_class_aclcheck(relOid, userid, thisPerm);
 433                 if (aclcheck_result != ACLCHECK_OK)
 434                         aclcheck_error(aclcheck_result, ACL_KIND_CLASS,
 435                                                    get_rel_name(relOid));
 436         }
 437 }
 438
 439 /*
 440  * Check that the query does not imply any writes to non-temp tables.
 441  */
 442 static void
 443 ExecCheckXactReadOnly(Query *parsetree)
 444 {
 445         List       *lp;
 446
 447         /*
 448          * CREATE TABLE AS or SELECT INTO?
 449          *
 450          * XXX should we allow this if the destination is temp?
 451          */
 452         if (parsetree->into != NULL)
 453                 goto fail;
 454
 455         /* Fail if write permissions are requested on any non-temp table */
 456         foreach(lp, parsetree->rtable)
 457         {
 458                 RangeTblEntry *rte = lfirst(lp);
 459
 460                 if (rte->rtekind == RTE_SUBQUERY)
 461                 {
 462                         ExecCheckXactReadOnly(rte->subquery);
 463                         continue;
 464                 }
 465
 466                 if (rte->rtekind != RTE_RELATION)
 467                         continue;
 468
 469                 if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
 470                         continue;
 471
 472                 if (isTempNamespace(get_rel_namespace(rte->relid)))
 473                         continue;
 474
 475                 goto fail;
 476         }
 477
 478         return;
 479
 480 fail:
 481         ereport(ERROR,
 482                         (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
 483                          errmsg("transaction is read-only")));
 484 }
 485
 486
 487 /* ----------------------------------------------------------------
 488  *              InitPlan
 489  *
 490  *              Initializes the query plan: open files, allocate storage
 491  *              and start up the rule manager
 492  * ----------------------------------------------------------------
 493  */
 494 static void
 495 InitPlan(QueryDesc *queryDesc, bool explainOnly)
 496 {
 497         CmdType         operation = queryDesc->operation;
 498         Query      *parseTree = queryDesc->parsetree;
 499         Plan       *plan = queryDesc->plantree;
 500         EState     *estate = queryDesc->estate;
 501         PlanState  *planstate;
 502         List       *rangeTable;
 503         Relation        intoRelationDesc;
 504         bool            do_select_into;
 505         TupleDesc       tupType;
 506
 507         /*
 508          * Do permissions checks.  It's sufficient to examine the query's top
 509          * rangetable here --- subplan RTEs will be checked during
 510          * ExecInitSubPlan().
 511          */
 512         ExecCheckRTPerms(parseTree->rtable);
 513
 514         /*
 515          * get information from query descriptor
 516          */
 517         rangeTable = parseTree->rtable;
 518
 519         /*
 520          * initialize the node's execution state
 521          */
 522         estate->es_range_table = rangeTable;
 523
 524         /*
 525          * if there is a result relation, initialize result relation stuff
 526          */
 527         if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
 528         {
 529                 List       *resultRelations = parseTree->resultRelations;
 530                 int                     numResultRelations;
 531                 ResultRelInfo *resultRelInfos;
 532
 533                 if (resultRelations != NIL)
 534                 {
 535                         /*
 536                          * Multiple result relations (due to inheritance)
 537                          * parseTree->resultRelations identifies them all
 538                          */
 539                         ResultRelInfo *resultRelInfo;
 540
 541                         numResultRelations = length(resultRelations);
 542                         resultRelInfos = (ResultRelInfo *)
 543                                 palloc(numResultRelations * sizeof(ResultRelInfo));
 544                         resultRelInfo = resultRelInfos;
 545                         while (resultRelations != NIL)
 546                         {
 547                                 initResultRelInfo(resultRelInfo,
 548                                                                   lfirsti(resultRelations),
 549                                                                   rangeTable,
 550                                                                   operation);
 551                                 resultRelInfo++;
 552                                 resultRelations = lnext(resultRelations);
 553                         }
 554                 }
 555                 else
 556                 {
 557                         /*
 558                          * Single result relation identified by
 559                          * parseTree->resultRelation
 560                          */
 561                         numResultRelations = 1;
 562                         resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
 563                         initResultRelInfo(resultRelInfos,
 564                                                           parseTree->resultRelation,
 565                                                           rangeTable,
 566                                                           operation);
 567                 }
 568
 569                 estate->es_result_relations = resultRelInfos;
 570                 estate->es_num_result_relations = numResultRelations;
 571                 /* Initialize to first or only result rel */
 572                 estate->es_result_relation_info = resultRelInfos;
 573         }
 574         else
 575         {
 576                 /*
 577                  * if no result relation, then set state appropriately
 578                  */
 579                 estate->es_result_relations = NULL;
 580                 estate->es_num_result_relations = 0;
 581                 estate->es_result_relation_info = NULL;
 582         }
 583
 584         /*
 585          * Detect whether we're doing SELECT INTO.  If so, set the force_oids
 586          * flag appropriately so that the plan tree will be initialized with
 587          * the correct tuple descriptors.
 588          */
 589         do_select_into = false;
 590
 591         if (operation == CMD_SELECT && parseTree->into != NULL)
 592         {
 593                 do_select_into = true;
 594                 estate->es_force_oids = parseTree->intoHasOids;
 595         }
 596
 597         /*
 598          * Have to lock relations selected for update
 599          */
 600         estate->es_rowMark = NIL;
 601         if (parseTree->rowMarks != NIL)
 602         {
 603                 List       *l;
 604
 605                 foreach(l, parseTree->rowMarks)
 606                 {
 607                         Index           rti = lfirsti(l);
 608                         Oid                     relid = getrelid(rti, rangeTable);
 609                         Relation        relation;
 610                         execRowMark *erm;
 611
 612                         relation = heap_open(relid, RowShareLock);
 613                         erm = (execRowMark *) palloc(sizeof(execRowMark));
 614                         erm->relation = relation;
 615                         erm->rti = rti;
 616                         snprintf(erm->resname, sizeof(erm->resname), "ctid%u", rti);
 617                         estate->es_rowMark = lappend(estate->es_rowMark, erm);
 618                 }
 619         }
 620
 621         /*
 622          * initialize the executor "tuple" table.  We need slots for all the
 623          * plan nodes, plus possibly output slots for the junkfilter(s). At
 624          * this point we aren't sure if we need junkfilters, so just add slots
 625          * for them unconditionally.
 626          */
 627         {
 628                 int                     nSlots = ExecCountSlotsNode(plan);
 629
 630                 if (parseTree->resultRelations != NIL)
 631                         nSlots += length(parseTree->resultRelations);
 632                 else
 633                         nSlots += 1;
 634                 estate->es_tupleTable = ExecCreateTupleTable(nSlots);
 635         }
 636
 637         /* mark EvalPlanQual not active */
 638         estate->es_topPlan = plan;
 639         estate->es_evalPlanQual = NULL;
 640         estate->es_evTupleNull = NULL;
 641         estate->es_evTuple = NULL;
 642         estate->es_useEvalPlan = false;
 643
 644         /*
 645          * initialize the private state information for all the nodes in the
 646          * query tree.  This opens files, allocates storage and leaves us
 647          * ready to start processing tuples.
 648          */
 649         planstate = ExecInitNode(plan, estate);
 650
 651         /*
 652          * Get the tuple descriptor describing the type of tuples to return.
 653          * (this is especially important if we are creating a relation with
 654          * "SELECT INTO")
 655          */
 656         tupType = ExecGetResultType(planstate);
 657
 658         /*
 659          * Initialize the junk filter if needed.  SELECT and INSERT queries
 660          * need a filter if there are any junk attrs in the tlist.      INSERT and
 661          * SELECT INTO also need a filter if the top plan node is a scan node
 662          * that's not doing projection (else we'll be scribbling on the scan
 663          * tuple!)      UPDATE and DELETE always need a filter, since there's
 664          * always a junk 'ctid' attribute present --- no need to look first.
 665          */
 666         {
 667                 bool            junk_filter_needed = false;
 668                 List       *tlist;
 669
 670                 switch (operation)
 671                 {
 672                         case CMD_SELECT:
 673                         case CMD_INSERT:
 674                                 foreach(tlist, plan->targetlist)
 675                                 {
 676                                         TargetEntry *tle = (TargetEntry *) lfirst(tlist);
 677
 678                                         if (tle->resdom->resjunk)
 679                                         {
 680                                                 junk_filter_needed = true;
 681                                                 break;
 682                                         }
 683                                 }
 684                                 if (!junk_filter_needed &&
 685                                         (operation == CMD_INSERT || do_select_into))
 686                                 {
 687                                         if (IsA(planstate, SeqScanState) ||
 688                                                 IsA(planstate, IndexScanState) ||
 689                                                 IsA(planstate, TidScanState) ||
 690                                                 IsA(planstate, SubqueryScanState) ||
 691                                                 IsA(planstate, FunctionScanState))
 692                                         {
 693                                                 if (planstate->ps_ProjInfo == NULL)
 694                                                         junk_filter_needed = true;
 695                                         }
 696                                 }
 697                                 break;
 698                         case CMD_UPDATE:
 699                         case CMD_DELETE:
 700                                 junk_filter_needed = true;
 701                                 break;
 702                         default:
 703                                 break;
 704                 }
 705
 706                 if (junk_filter_needed)
 707                 {
 708                         /*
 709                          * If there are multiple result relations, each one needs its
 710                          * own junk filter.  Note this is only possible for
 711                          * UPDATE/DELETE, so we can't be fooled by some needing a
 712                          * filter and some not.
 713                          */
 714                         if (parseTree->resultRelations != NIL)
 715                         {
 716                                 PlanState **appendplans;
 717                                 int                     as_nplans;
 718                                 ResultRelInfo *resultRelInfo;
 719                                 int                     i;
 720
 721                                 /* Top plan had better be an Append here. */
 722                                 Assert(IsA(plan, Append));
 723                                 Assert(((Append *) plan)->isTarget);
 724                                 Assert(IsA(planstate, AppendState));
 725                                 appendplans = ((AppendState *) planstate)->appendplans;
 726                                 as_nplans = ((AppendState *) planstate)->as_nplans;
 727                                 Assert(as_nplans == estate->es_num_result_relations);
 728                                 resultRelInfo = estate->es_result_relations;
 729                                 for (i = 0; i < as_nplans; i++)
 730                                 {
 731                                         PlanState  *subplan = appendplans[i];
 732                                         JunkFilter *j;
 733
 734                                         j = ExecInitJunkFilter(subplan->plan->targetlist,
 735                                                                                    ExecGetResultType(subplan),
 736                                                           ExecAllocTableSlot(estate->es_tupleTable));
 737                                         resultRelInfo->ri_junkFilter = j;
 738                                         resultRelInfo++;
 739                                 }
 740
 741                                 /*
 742                                  * Set active junkfilter too; at this point ExecInitAppend
 743                                  * has already selected an active result relation...
 744                                  */
 745                                 estate->es_junkFilter =
 746                                         estate->es_result_relation_info->ri_junkFilter;
 747                         }
 748                         else
 749                         {
 750                                 /* Normal case with just one JunkFilter */
 751                                 JunkFilter *j;
 752
 753                                 j = ExecInitJunkFilter(planstate->plan->targetlist,
 754                                                                            tupType,
 755                                                           ExecAllocTableSlot(estate->es_tupleTable));
 756                                 estate->es_junkFilter = j;
 757                                 if (estate->es_result_relation_info)
 758                                         estate->es_result_relation_info->ri_junkFilter = j;
 759
 760                                 /* For SELECT, want to return the cleaned tuple type */
 761                                 if (operation == CMD_SELECT)
 762                                         tupType = j->jf_cleanTupType;
 763                         }
 764                 }
 765                 else
 766                         estate->es_junkFilter = NULL;
 767         }
 768
 769         /*
 770          * If doing SELECT INTO, initialize the "into" relation.  We must wait
 771          * till now so we have the "clean" result tuple type to create the new
 772          * table from.
 773          *
 774          * If EXPLAIN, skip creating the "into" relation.
 775          */
 776         intoRelationDesc = NULL;
 777
 778         if (do_select_into && !explainOnly)
 779         {
 780                 char       *intoName;
 781                 Oid                     namespaceId;
 782                 AclResult       aclresult;
 783                 Oid                     intoRelationId;
 784                 TupleDesc       tupdesc;
 785
 786                 /*
 787                  * find namespace to create in, check permissions
 788                  */
 789                 intoName = parseTree->into->relname;
 790                 namespaceId = RangeVarGetCreationNamespace(parseTree->into);
 791
 792                 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
 793                                                                                   ACL_CREATE);
 794                 if (aclresult != ACLCHECK_OK)
 795                         aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
 796                                                    get_namespace_name(namespaceId));
 797
 798                 /*
 799                  * have to copy tupType to get rid of constraints
 800                  */
 801                 tupdesc = CreateTupleDescCopy(tupType);
 802
 803                 intoRelationId = heap_create_with_catalog(intoName,
 804                                                                                                   namespaceId,
 805                                                                                                   tupdesc,
 806                                                                                                   RELKIND_RELATION,
 807                                                                                                   false,
 808                                                                                                   ONCOMMIT_NOOP,
 809                                                                                                   allowSystemTableMods);
 810
 811                 FreeTupleDesc(tupdesc);
 812
 813                 /*
 814                  * Advance command counter so that the newly-created relation's
 815                  * catalog tuples will be visible to heap_open.
 816                  */
 817                 CommandCounterIncrement();
 818
 819                 /*
 820                  * If necessary, create a TOAST table for the into relation. Note
 821                  * that AlterTableCreateToastTable ends with
 822                  * CommandCounterIncrement(), so that the TOAST table will be
 823                  * visible for insertion.
 824                  */
 825                 AlterTableCreateToastTable(intoRelationId, true);
 826
 827                 /*
 828                  * And open the constructed table for writing.
 829                  */
 830                 intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
 831         }
 832
 833         estate->es_into_relation_descriptor = intoRelationDesc;
 834
 835         queryDesc->tupDesc = tupType;
 836         queryDesc->planstate = planstate;
 837 }
 838
 839 /*
 840  * Initialize ResultRelInfo data for one result relation
 841  */
 842 static void
 843 initResultRelInfo(ResultRelInfo *resultRelInfo,
 844                                   Index resultRelationIndex,
 845                                   List *rangeTable,
 846                                   CmdType operation)
 847 {
 848         Oid                     resultRelationOid;
 849         Relation        resultRelationDesc;
 850
 851         resultRelationOid = getrelid(resultRelationIndex, rangeTable);
 852         resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
 853
 854         switch (resultRelationDesc->rd_rel->relkind)
 855         {
 856                 case RELKIND_SEQUENCE:
 857                         ereport(ERROR,
 858                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 859                                          errmsg("cannot change sequence \"%s\"",
 860                                                   RelationGetRelationName(resultRelationDesc))));
 861                         break;
 862                 case RELKIND_TOASTVALUE:
 863                         ereport(ERROR,
 864                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 865                                          errmsg("cannot change TOAST relation \"%s\"",
 866                                                   RelationGetRelationName(resultRelationDesc))));
 867                         break;
 868                 case RELKIND_VIEW:
 869                         ereport(ERROR,
 870                                         (errcode(ERRCODE_WRONG_OBJECT_TYPE),
 871                                          errmsg("cannot change view \"%s\"",
 872                                                   RelationGetRelationName(resultRelationDesc))));
 873                         break;
 874         }
 875
 876         MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
 877         resultRelInfo->type = T_ResultRelInfo;
 878         resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
 879         resultRelInfo->ri_RelationDesc = resultRelationDesc;
 880         resultRelInfo->ri_NumIndices = 0;
 881         resultRelInfo->ri_IndexRelationDescs = NULL;
 882         resultRelInfo->ri_IndexRelationInfo = NULL;
 883         /* make a copy so as not to depend on relcache info not changing... */
 884         resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
 885         resultRelInfo->ri_TrigFunctions = NULL;
 886         resultRelInfo->ri_ConstraintExprs = NULL;
 887         resultRelInfo->ri_junkFilter = NULL;
 888
 889         /*
 890          * If there are indices on the result relation, open them and save
 891          * descriptors in the result relation info, so that we can add new
 892          * index entries for the tuples we add/update.  We need not do this
 893          * for a DELETE, however, since deletion doesn't affect indexes.
 894          */
 895         if (resultRelationDesc->rd_rel->relhasindex &&
 896                 operation != CMD_DELETE)
 897                 ExecOpenIndices(resultRelInfo);
 898 }
 899
 900 /* ----------------------------------------------------------------
 901  *              ExecEndPlan
 902  *
 903  *              Cleans up the query plan -- closes files and frees up storage
 904  *
 905  * NOTE: we are no longer very worried about freeing storage per se
 906  * in this code; FreeExecutorState should be guaranteed to release all
 907  * memory that needs to be released.  What we are worried about doing
 908  * is closing relations and dropping buffer pins.  Thus, for example,
 909  * tuple tables must be cleared or dropped to ensure pins are released.
 910  * ----------------------------------------------------------------
 911  */
 912 void
 913 ExecEndPlan(PlanState *planstate, EState *estate)
 914 {
 915         ResultRelInfo *resultRelInfo;
 916         int                     i;
 917         List       *l;
 918
 919         /*
 920          * shut down any PlanQual processing we were doing
 921          */
 922         if (estate->es_evalPlanQual != NULL)
 923                 EndEvalPlanQual(estate);
 924
 925         /*
 926          * shut down the node-type-specific query processing
 927          */
 928         ExecEndNode(planstate);
 929
 930         /*
 931          * destroy the executor "tuple" table.
 932          */
 933         ExecDropTupleTable(estate->es_tupleTable, true);
 934         estate->es_tupleTable = NULL;
 935
 936         /*
 937          * close the result relation(s) if any, but hold locks until xact
 938          * commit.
 939          */
 940         resultRelInfo = estate->es_result_relations;
 941         for (i = estate->es_num_result_relations; i > 0; i--)
 942         {
 943                 /* Close indices and then the relation itself */
 944                 ExecCloseIndices(resultRelInfo);
 945                 heap_close(resultRelInfo->ri_RelationDesc, NoLock);
 946                 resultRelInfo++;
 947         }
 948
 949         /*
 950          * close the "into" relation if necessary, again keeping lock
 951          */
 952         if (estate->es_into_relation_descriptor != NULL)
 953                 heap_close(estate->es_into_relation_descriptor, NoLock);
 954
 955         /*
 956          * close any relations selected FOR UPDATE, again keeping locks
 957          */
 958         foreach(l, estate->es_rowMark)
 959         {
 960                 execRowMark *erm = lfirst(l);
 961
 962                 heap_close(erm->relation, NoLock);
 963         }
 964 }
 965
 966 /* ----------------------------------------------------------------
 967  *              ExecutePlan
 968  *
 969  *              processes the query plan to retrieve 'numberTuples' tuples in the
 970  *              direction specified.
 971  *
 972  *              Retrieves all tuples if numberTuples is 0
 973  *
 974  *              result is either a slot containing the last tuple in the case
 975  *              of a SELECT or NULL otherwise.
 976  *
 977  * Note: the ctid attribute is a 'junk' attribute that is removed before the
 978  * user can see it
 979  * ----------------------------------------------------------------
 980  */
 981 static TupleTableSlot *
 982 ExecutePlan(EState *estate,
 983                         PlanState *planstate,
 984                         CmdType operation,
 985                         long numberTuples,
 986                         ScanDirection direction,
 987                         DestReceiver *dest)
 988 {
 989         JunkFilter *junkfilter;
 990         TupleTableSlot *slot;
 991         ItemPointer tupleid = NULL;
 992         ItemPointerData tuple_ctid;
 993         long            current_tuple_count;
 994         TupleTableSlot *result;
 995
 996         /*
 997          * initialize local variables
 998          */
 999         slot = NULL;
1000         current_tuple_count = 0;
1001         result = NULL;
1002
1003         /*
1004          * Set the direction.
1005          */
1006         estate->es_direction = direction;
1007
1008         /*
1009          * Process BEFORE EACH STATEMENT triggers
1010          */
1011         switch (operation)
1012         {
1013                 case CMD_UPDATE:
1014                         ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
1015                         break;
1016                 case CMD_DELETE:
1017                         ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
1018                         break;
1019                 case CMD_INSERT:
1020                         ExecBSInsertTriggers(estate, estate->es_result_relation_info);
1021                         break;
1022                 default:
1023                         /* do nothing */
1024                         break;
1025         }
1026
1027         /*
1028          * Loop until we've processed the proper number of tuples from the
1029          * plan.
1030          */
1031
1032         for (;;)
1033         {
1034                 /* Reset the per-output-tuple exprcontext */
1035                 ResetPerTupleExprContext(estate);
1036
1037                 /*
1038                  * Execute the plan and obtain a tuple
1039                  */
1040 lnext:  ;
1041                 if (estate->es_useEvalPlan)
1042                 {
1043                         slot = EvalPlanQualNext(estate);
1044                         if (TupIsNull(slot))
1045                                 slot = ExecProcNode(planstate);
1046                 }
1047                 else
1048                         slot = ExecProcNode(planstate);
1049
1050                 /*
1051                  * if the tuple is null, then we assume there is nothing more to
1052                  * process so we just return null...
1053                  */
1054                 if (TupIsNull(slot))
1055                 {
1056                         result = NULL;
1057                         break;
1058                 }
1059
1060                 /*
1061                  * if we have a junk filter, then project a new tuple with the
1062                  * junk removed.
1063                  *
1064                  * Store this new "clean" tuple in the junkfilter's resultSlot.
1065                  * (Formerly, we stored it back over the "dirty" tuple, which is
1066                  * WRONG because that tuple slot has the wrong descriptor.)
1067                  *
1068                  * Also, extract all the junk information we need.
1069                  */
1070                 if ((junkfilter = estate->es_junkFilter) != NULL)
1071                 {
1072                         Datum           datum;
1073                         HeapTuple       newTuple;
1074                         bool            isNull;
1075
1076                         /*
1077                          * extract the 'ctid' junk attribute.
1078                          */
1079                         if (operation == CMD_UPDATE || operation == CMD_DELETE)
1080                         {
1081                                 if (!ExecGetJunkAttribute(junkfilter,
1082                                                                                   slot,
1083                                                                                   "ctid",
1084                                                                                   &datum,
1085                                                                                   &isNull))
1086                                         elog(ERROR, "could not find junk ctid column");
1087
1088                                 /* shouldn't ever get a null result... */
1089                                 if (isNull)
1090                                         elog(ERROR, "ctid is NULL");
1091
1092                                 tupleid = (ItemPointer) DatumGetPointer(datum);
1093                                 tuple_ctid = *tupleid;  /* make sure we don't free the
1094                                                                                  * ctid!! */
1095                                 tupleid = &tuple_ctid;
1096                         }
1097                         else if (estate->es_rowMark != NIL)
1098                         {
1099                                 List       *l;
1100
1101                 lmark:  ;
1102                                 foreach(l, estate->es_rowMark)
1103                                 {
1104                                         execRowMark *erm = lfirst(l);
1105                                         Buffer          buffer;
1106                                         HeapTupleData tuple;
1107                                         TupleTableSlot *newSlot;
1108                                         int                     test;
1109
1110                                         if (!ExecGetJunkAttribute(junkfilter,
1111                                                                                           slot,
1112                                                                                           erm->resname,
1113                                                                                           &datum,
1114                                                                                           &isNull))
1115                                                 elog(ERROR, "could not find junk \"%s\" column",
1116                                                          erm->resname);
1117
1118                                         /* shouldn't ever get a null result... */
1119                                         if (isNull)
1120                                                 elog(ERROR, "\"%s\" is NULL", erm->resname);
1121
1122                                         tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
1123                                         test = heap_mark4update(erm->relation, &tuple, &buffer,
1124                                                                                         estate->es_snapshot->curcid);
1125                                         ReleaseBuffer(buffer);
1126                                         switch (test)
1127                                         {
1128                                                 case HeapTupleSelfUpdated:
1129                                                         /* treat it as deleted; do not process */
1130                                                         goto lnext;
1131
1132                                                 case HeapTupleMayBeUpdated:
1133                                                         break;
1134
1135                                                 case HeapTupleUpdated:
1136                                                         if (IsXactIsoLevelSerializable)
1137                                                                 ereport(ERROR,
1138                                                                                 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1139                                                                                  errmsg("could not serialize access due to concurrent update")));
1140                                                         if (!(ItemPointerEquals(&(tuple.t_self),
1141                                                                   (ItemPointer) DatumGetPointer(datum))))
1142                                                         {
1143                                                                 newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
1144                                                                 if (!(TupIsNull(newSlot)))
1145                                                                 {
1146                                                                         slot = newSlot;
1147                                                                         estate->es_useEvalPlan = true;
1148                                                                         goto lmark;
1149                                                                 }
1150                                                         }
1151
1152                                                         /*
1153                                                          * if tuple was deleted or PlanQual failed for
1154                                                          * updated tuple - we must not return this
1155                                                          * tuple!
1156                                                          */
1157                                                         goto lnext;
1158
1159                                                 default:
1160                                                         elog(ERROR, "unrecognized heap_mark4update status: %u",
1161                                                                  test);
1162                                                         return (NULL);
1163                                         }
1164                                 }
1165                         }
1166
1167                         /*
1168                          * Finally create a new "clean" tuple with all junk attributes
1169                          * removed
1170                          */
1171                         newTuple = ExecRemoveJunk(junkfilter, slot);
1172
1173                         slot = ExecStoreTuple(newTuple,         /* tuple to store */
1174                                                                   junkfilter->jf_resultSlot,    /* dest slot */
1175                                                                   InvalidBuffer,                /* this tuple has no
1176                                                                                                                  * buffer */
1177                                                                   true);                /* tuple should be pfreed */
1178                 }
1179
1180                 /*
1181                  * now that we have a tuple, do the appropriate thing with it..
1182                  * either return it to the user, add it to a relation someplace,
1183                  * delete it from a relation, or modify some of its attributes.
1184                  */
1185                 switch (operation)
1186                 {
1187                         case CMD_SELECT:
1188                                 ExecSelect(slot,        /* slot containing tuple */
1189                                                    dest,        /* destination's tuple-receiver obj */
1190                                                    estate);
1191                                 result = slot;
1192                                 break;
1193
1194                         case CMD_INSERT:
1195                                 ExecInsert(slot, tupleid, estate);
1196                                 result = NULL;
1197                                 break;
1198
1199                         case CMD_DELETE:
1200                                 ExecDelete(slot, tupleid, estate);
1201                                 result = NULL;
1202                                 break;
1203
1204                         case CMD_UPDATE:
1205                                 ExecUpdate(slot, tupleid, estate);
1206                                 result = NULL;
1207                                 break;
1208
1209                         default:
1210                                 elog(ERROR, "unrecognized operation code: %d",
1211                                          (int) operation);
1212                                 result = NULL;
1213                                 break;
1214                 }
1215
1216                 /*
1217                  * check our tuple count.. if we've processed the proper number
1218                  * then quit, else loop again and process more tuples.  Zero
1219                  * numberTuples means no limit.
1220                  */
1221                 current_tuple_count++;
1222                 if (numberTuples && numberTuples == current_tuple_count)
1223                         break;
1224         }
1225
1226         /*
1227          * Process AFTER EACH STATEMENT triggers
1228          */
1229         switch (operation)
1230         {
1231                 case CMD_UPDATE:
1232                         ExecASUpdateTriggers(estate, estate->es_result_relation_info);
1233                         break;
1234                 case CMD_DELETE:
1235                         ExecASDeleteTriggers(estate, estate->es_result_relation_info);
1236                         break;
1237                 case CMD_INSERT:
1238                         ExecASInsertTriggers(estate, estate->es_result_relation_info);
1239                         break;
1240                 default:
1241                         /* do nothing */
1242                         break;
1243         }
1244
1245         /*
1246          * here, result is either a slot containing a tuple in the case of a
1247          * SELECT or NULL otherwise.
1248          */
1249         return result;
1250 }
1251
1252 /* ----------------------------------------------------------------
1253  *              ExecSelect
1254  *
1255  *              SELECTs are easy.. we just pass the tuple to the appropriate
1256  *              print function.  The only complexity is when we do a
1257  *              "SELECT INTO", in which case we insert the tuple into
1258  *              the appropriate relation (note: this is a newly created relation
1259  *              so we don't need to worry about indices or locks.)
1260  * ----------------------------------------------------------------
1261  */
1262 static void
1263 ExecSelect(TupleTableSlot *slot,
1264                    DestReceiver *dest,
1265                    EState *estate)
1266 {
1267         HeapTuple       tuple;
1268         TupleDesc       attrtype;
1269
1270         /*
1271          * get the heap tuple out of the tuple table slot
1272          */
1273         tuple = slot->val;
1274         attrtype = slot->ttc_tupleDescriptor;
1275
1276         /*
1277          * insert the tuple into the "into relation"
1278          *
1279          * XXX this probably ought to be replaced by a separate destination
1280          */
1281         if (estate->es_into_relation_descriptor != NULL)
1282         {
1283                 heap_insert(estate->es_into_relation_descriptor, tuple,
1284                                         estate->es_snapshot->curcid);
1285                 IncrAppended();
1286         }
1287
1288         /*
1289          * send the tuple to the destination
1290          */
1291         (*dest->receiveTuple) (tuple, attrtype, dest);
1292         IncrRetrieved();
1293         (estate->es_processed)++;
1294 }
1295
1296 /* ----------------------------------------------------------------
1297  *              ExecInsert
1298  *
1299  *              INSERTs are trickier.. we have to insert the tuple into
1300  *              the base relation and insert appropriate tuples into the
1301  *              index relations.
1302  * ----------------------------------------------------------------
1303  */
1304 static void
1305 ExecInsert(TupleTableSlot *slot,
1306                    ItemPointer tupleid,
1307                    EState *estate)
1308 {
1309         HeapTuple       tuple;
1310         ResultRelInfo *resultRelInfo;
1311         Relation        resultRelationDesc;
1312         int                     numIndices;
1313         Oid                     newId;
1314
1315         /*
1316          * get the heap tuple out of the tuple table slot
1317          */
1318         tuple = slot->val;
1319
1320         /*
1321          * get information on the (current) result relation
1322          */
1323         resultRelInfo = estate->es_result_relation_info;
1324         resultRelationDesc = resultRelInfo->ri_RelationDesc;
1325
1326         /* BEFORE ROW INSERT Triggers */
1327         if (resultRelInfo->ri_TrigDesc &&
1328           resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
1329         {
1330                 HeapTuple       newtuple;
1331
1332                 newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
1333
1334                 if (newtuple == NULL)   /* "do nothing" */
1335                         return;
1336
1337                 if (newtuple != tuple)  /* modified by Trigger(s) */
1338                 {
1339                         /*
1340                          * Insert modified tuple into tuple table slot, replacing the
1341                          * original.  We assume that it was allocated in per-tuple
1342                          * memory context, and therefore will go away by itself. The
1343                          * tuple table slot should not try to clear it.
1344                          */
1345                         ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1346                         tuple = newtuple;
1347                 }
1348         }
1349
1350         /*
1351          * Check the constraints of the tuple
1352          */
1353         if (resultRelationDesc->rd_att->constr)
1354                 ExecConstraints(resultRelInfo, slot, estate);
1355
1356         /*
1357          * insert the tuple
1358          */
1359         newId = heap_insert(resultRelationDesc, tuple,
1360                                                 estate->es_snapshot->curcid);
1361
1362         IncrAppended();
1363         (estate->es_processed)++;
1364         estate->es_lastoid = newId;
1365         setLastTid(&(tuple->t_self));
1366
1367         /*
1368          * process indices
1369          *
1370          * Note: heap_insert adds a new tuple to a relation.  As a side effect,
1371          * the tupleid of the new tuple is placed in the new tuple's t_ctid
1372          * field.
1373          */
1374         numIndices = resultRelInfo->ri_NumIndices;
1375         if (numIndices > 0)
1376                 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1377
1378         /* AFTER ROW INSERT Triggers */
1379         ExecARInsertTriggers(estate, resultRelInfo, tuple);
1380 }
1381
1382 /* ----------------------------------------------------------------
1383  *              ExecDelete
1384  *
1385  *              DELETE is like UPDATE, we delete the tuple and its
1386  *              index tuples.
1387  * ----------------------------------------------------------------
1388  */
1389 static void
1390 ExecDelete(TupleTableSlot *slot,
1391                    ItemPointer tupleid,
1392                    EState *estate)
1393 {
1394         ResultRelInfo *resultRelInfo;
1395         Relation        resultRelationDesc;
1396         ItemPointerData ctid;
1397         int                     result;
1398
1399         /*
1400          * get information on the (current) result relation
1401          */
1402         resultRelInfo = estate->es_result_relation_info;
1403         resultRelationDesc = resultRelInfo->ri_RelationDesc;
1404
1405         /* BEFORE ROW DELETE Triggers */
1406         if (resultRelInfo->ri_TrigDesc &&
1407           resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
1408         {
1409                 bool            dodelete;
1410
1411                 dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
1412                                                                                 estate->es_snapshot->curcid);
1413
1414                 if (!dodelete)                  /* "do nothing" */
1415                         return;
1416         }
1417
1418         /*
1419          * delete the tuple
1420          */
1421 ldelete:;
1422         result = heap_delete(resultRelationDesc, tupleid,
1423                                                  &ctid,
1424                                                  estate->es_snapshot->curcid,
1425                                                  estate->es_crosscheck_snapshot,
1426                                                  true /* wait for commit */);
1427         switch (result)
1428         {
1429                 case HeapTupleSelfUpdated:
1430                         /* already deleted by self; nothing to do */
1431                         return;
1432
1433                 case HeapTupleMayBeUpdated:
1434                         break;
1435
1436                 case HeapTupleUpdated:
1437                         if (IsXactIsoLevelSerializable)
1438                                 ereport(ERROR,
1439                                                 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1440                                                  errmsg("could not serialize access due to concurrent update")));
1441                         else if (!(ItemPointerEquals(tupleid, &ctid)))
1442                         {
1443                                 TupleTableSlot *epqslot = EvalPlanQual(estate,
1444                                                            resultRelInfo->ri_RangeTableIndex, &ctid);
1445
1446                                 if (!TupIsNull(epqslot))
1447                                 {
1448                                         *tupleid = ctid;
1449                                         goto ldelete;
1450                                 }
1451                         }
1452                         /* tuple already deleted; nothing to do */
1453                         return;
1454
1455                 default:
1456                         elog(ERROR, "unrecognized heap_delete status: %u", result);
1457                         return;
1458         }
1459
1460         IncrDeleted();
1461         (estate->es_processed)++;
1462
1463         /*
1464          * Note: Normally one would think that we have to delete index tuples
1465          * associated with the heap tuple now..
1466          *
1467          * ... but in POSTGRES, we have no need to do this because the vacuum
1468          * daemon automatically opens an index scan and deletes index tuples
1469          * when it finds deleted heap tuples. -cim 9/27/89
1470          */
1471
1472         /* AFTER ROW DELETE Triggers */
1473         ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
1474 }
1475
1476 /* ----------------------------------------------------------------
1477  *              ExecUpdate
1478  *
1479  *              note: we can't run UPDATE queries with transactions
1480  *              off because UPDATEs are actually INSERTs and our
1481  *              scan will mistakenly loop forever, updating the tuple
1482  *              it just inserted..      This should be fixed but until it
1483  *              is, we don't want to get stuck in an infinite loop
1484  *              which corrupts your database..
1485  * ----------------------------------------------------------------
1486  */
1487 static void
1488 ExecUpdate(TupleTableSlot *slot,
1489                    ItemPointer tupleid,
1490                    EState *estate)
1491 {
1492         HeapTuple       tuple;
1493         ResultRelInfo *resultRelInfo;
1494         Relation        resultRelationDesc;
1495         ItemPointerData ctid;
1496         int                     result;
1497         int                     numIndices;
1498
1499         /*
1500          * abort the operation if not running transactions
1501          */
1502         if (IsBootstrapProcessingMode())
1503                 elog(ERROR, "cannot UPDATE during bootstrap");
1504
1505         /*
1506          * get the heap tuple out of the tuple table slot
1507          */
1508         tuple = slot->val;
1509
1510         /*
1511          * get information on the (current) result relation
1512          */
1513         resultRelInfo = estate->es_result_relation_info;
1514         resultRelationDesc = resultRelInfo->ri_RelationDesc;
1515
1516         /* BEFORE ROW UPDATE Triggers */
1517         if (resultRelInfo->ri_TrigDesc &&
1518           resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
1519         {
1520                 HeapTuple       newtuple;
1521
1522                 newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
1523                                                                                 tupleid, tuple,
1524                                                                                 estate->es_snapshot->curcid);
1525
1526                 if (newtuple == NULL)   /* "do nothing" */
1527                         return;
1528
1529                 if (newtuple != tuple)  /* modified by Trigger(s) */
1530                 {
1531                         /*
1532                          * Insert modified tuple into tuple table slot, replacing the
1533                          * original.  We assume that it was allocated in per-tuple
1534                          * memory context, and therefore will go away by itself. The
1535                          * tuple table slot should not try to clear it.
1536                          */
1537                         ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
1538                         tuple = newtuple;
1539                 }
1540         }
1541
1542         /*
1543          * Check the constraints of the tuple
1544          *
1545          * If we generate a new candidate tuple after EvalPlanQual testing, we
1546          * must loop back here and recheck constraints.  (We don't need to
1547          * redo triggers, however.      If there are any BEFORE triggers then
1548          * trigger.c will have done mark4update to lock the correct tuple, so
1549          * there's no need to do them again.)
1550          */
1551 lreplace:;
1552         if (resultRelationDesc->rd_att->constr)
1553                 ExecConstraints(resultRelInfo, slot, estate);
1554
1555         /*
1556          * replace the heap tuple
1557          */
1558         result = heap_update(resultRelationDesc, tupleid, tuple,
1559                                                  &ctid,
1560                                                  estate->es_snapshot->curcid,
1561                                                  estate->es_crosscheck_snapshot,
1562                                                  true /* wait for commit */);
1563         switch (result)
1564         {
1565                 case HeapTupleSelfUpdated:
1566                         /* already deleted by self; nothing to do */
1567                         return;
1568
1569                 case HeapTupleMayBeUpdated:
1570                         break;
1571
1572                 case HeapTupleUpdated:
1573                         if (IsXactIsoLevelSerializable)
1574                                 ereport(ERROR,
1575                                                 (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
1576                                                  errmsg("could not serialize access due to concurrent update")));
1577                         else if (!(ItemPointerEquals(tupleid, &ctid)))
1578                         {
1579                                 TupleTableSlot *epqslot = EvalPlanQual(estate,
1580                                                            resultRelInfo->ri_RangeTableIndex, &ctid);
1581
1582                                 if (!TupIsNull(epqslot))
1583                                 {
1584                                         *tupleid = ctid;
1585                                         tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
1586                                         slot = ExecStoreTuple(tuple,
1587                                                                         estate->es_junkFilter->jf_resultSlot,
1588                                                                                   InvalidBuffer, true);
1589                                         goto lreplace;
1590                                 }
1591                         }
1592                         /* tuple already deleted; nothing to do */
1593                         return;
1594
1595                 default:
1596                         elog(ERROR, "unrecognized heap_update status: %u", result);
1597                         return;
1598         }
1599
1600         IncrReplaced();
1601         (estate->es_processed)++;
1602
1603         /*
1604          * Note: instead of having to update the old index tuples associated
1605          * with the heap tuple, all we do is form and insert new index tuples.
1606          * This is because UPDATEs are actually DELETEs and INSERTs and index
1607          * tuple deletion is done automagically by the vacuum daemon. All we
1608          * do is insert new index tuples.  -cim 9/27/89
1609          */
1610
1611         /*
1612          * process indices
1613          *
1614          * heap_update updates a tuple in the base relation by invalidating it
1615          * and then inserting a new tuple to the relation.      As a side effect,
1616          * the tupleid of the new tuple is placed in the new tuple's t_ctid
1617          * field.  So we now insert index tuples using the new tupleid stored
1618          * there.
1619          */
1620
1621         numIndices = resultRelInfo->ri_NumIndices;
1622         if (numIndices > 0)
1623                 ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
1624
1625         /* AFTER ROW UPDATE Triggers */
1626         ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
1627 }
1628
1629 static const char *
1630 ExecRelCheck(ResultRelInfo *resultRelInfo,
1631                          TupleTableSlot *slot, EState *estate)
1632 {
1633         Relation        rel = resultRelInfo->ri_RelationDesc;
1634         int                     ncheck = rel->rd_att->constr->num_check;
1635         ConstrCheck *check = rel->rd_att->constr->check;
1636         ExprContext *econtext;
1637         MemoryContext oldContext;
1638         List       *qual;
1639         int                     i;
1640
1641         /*
1642          * If first time through for this result relation, build expression
1643          * nodetrees for rel's constraint expressions.  Keep them in the
1644          * per-query memory context so they'll survive throughout the query.
1645          */
1646         if (resultRelInfo->ri_ConstraintExprs == NULL)
1647         {
1648                 oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
1649                 resultRelInfo->ri_ConstraintExprs =
1650                         (List **) palloc(ncheck * sizeof(List *));
1651                 for (i = 0; i < ncheck; i++)
1652                 {
1653                         /* ExecQual wants implicit-AND form */
1654                         qual = make_ands_implicit(stringToNode(check[i].ccbin));
1655                         resultRelInfo->ri_ConstraintExprs[i] = (List *)
1656                                 ExecPrepareExpr((Expr *) qual, estate);
1657                 }
1658                 MemoryContextSwitchTo(oldContext);
1659         }
1660
1661         /*
1662          * We will use the EState's per-tuple context for evaluating
1663          * constraint expressions (creating it if it's not already there).
1664          */
1665         econtext = GetPerTupleExprContext(estate);
1666
1667         /* Arrange for econtext's scan tuple to be the tuple under test */
1668         econtext->ecxt_scantuple = slot;
1669
1670         /* And evaluate the constraints */
1671         for (i = 0; i < ncheck; i++)
1672         {
1673                 qual = resultRelInfo->ri_ConstraintExprs[i];
1674
1675                 /*
1676                  * NOTE: SQL92 specifies that a NULL result from a constraint
1677                  * expression is not to be treated as a failure.  Therefore, tell
1678                  * ExecQual to return TRUE for NULL.
1679                  */
1680                 if (!ExecQual(qual, econtext, true))
1681                         return check[i].ccname;
1682         }
1683
1684         /* NULL result means no error */
1685         return NULL;
1686 }
1687
1688 void
1689 ExecConstraints(ResultRelInfo *resultRelInfo,
1690                                 TupleTableSlot *slot, EState *estate)
1691 {
1692         Relation        rel = resultRelInfo->ri_RelationDesc;
1693         HeapTuple       tuple = slot->val;
1694         TupleConstr *constr = rel->rd_att->constr;
1695
1696         Assert(constr);
1697
1698         if (constr->has_not_null)
1699         {
1700                 int                     natts = rel->rd_att->natts;
1701                 int                     attrChk;
1702
1703                 for (attrChk = 1; attrChk <= natts; attrChk++)
1704                 {
1705                         if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
1706                                 heap_attisnull(tuple, attrChk))
1707                                 ereport(ERROR,
1708                                                 (errcode(ERRCODE_NOT_NULL_VIOLATION),
1709                                                  errmsg("null value in column \"%s\" violates not-null constraint",
1710                                         NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
1711                 }
1712         }
1713
1714         if (constr->num_check > 0)
1715         {
1716                 const char *failed;
1717
1718                 if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
1719                         ereport(ERROR,
1720                                         (errcode(ERRCODE_CHECK_VIOLATION),
1721                                          errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
1722                                                         RelationGetRelationName(rel), failed)));
1723         }
1724 }
1725
1726 /*
1727  * Check a modified tuple to see if we want to process its updated version
1728  * under READ COMMITTED rules.
1729  *
1730  * See backend/executor/README for some info about how this works.
1731  */
1732 TupleTableSlot *
1733 EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
1734 {
1735         evalPlanQual *epq;
1736         EState     *epqstate;
1737         Relation        relation;
1738         HeapTupleData tuple;
1739         HeapTuple       copyTuple = NULL;
1740         bool            endNode;
1741
1742         Assert(rti != 0);
1743
1744         /*
1745          * find relation containing target tuple
1746          */
1747         if (estate->es_result_relation_info != NULL &&
1748                 estate->es_result_relation_info->ri_RangeTableIndex == rti)
1749                 relation = estate->es_result_relation_info->ri_RelationDesc;
1750         else
1751         {
1752                 List       *l;
1753
1754                 relation = NULL;
1755                 foreach(l, estate->es_rowMark)
1756                 {
1757                         if (((execRowMark *) lfirst(l))->rti == rti)
1758                         {
1759                                 relation = ((execRowMark *) lfirst(l))->relation;
1760                                 break;
1761                         }
1762                 }
1763                 if (relation == NULL)
1764                         elog(ERROR, "could not find RowMark for RT index %u", rti);
1765         }
1766
1767         /*
1768          * fetch tid tuple
1769          *
1770          * Loop here to deal with updated or busy tuples
1771          */
1772         tuple.t_self = *tid;
1773         for (;;)
1774         {
1775                 Buffer          buffer;
1776
1777                 if (heap_fetch(relation, SnapshotDirty, &tuple, &buffer, false, NULL))
1778                 {
1779                         TransactionId xwait = SnapshotDirty->xmax;
1780
1781                         /* xmin should not be dirty... */
1782                         if (TransactionIdIsValid(SnapshotDirty->xmin))
1783                                 elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
1784
1785                         /*
1786                          * If tuple is being updated by other transaction then we have
1787                          * to wait for its commit/abort.
1788                          */
1789                         if (TransactionIdIsValid(xwait))
1790                         {
1791                                 ReleaseBuffer(buffer);
1792                                 XactLockTableWait(xwait);
1793                                 continue;
1794                         }
1795
1796                         /*
1797                          * We got tuple - now copy it for use by recheck query.
1798                          */
1799                         copyTuple = heap_copytuple(&tuple);
1800                         ReleaseBuffer(buffer);
1801                         break;
1802                 }
1803
1804                 /*
1805                  * Oops! Invalid tuple. Have to check is it updated or deleted.
1806                  * Note that it's possible to get invalid SnapshotDirty->tid if
1807                  * tuple updated by this transaction. Have we to check this ?
1808                  */
1809                 if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
1810                         !(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
1811                 {
1812                         /* updated, so look at the updated copy */
1813                         tuple.t_self = SnapshotDirty->tid;
1814                         continue;
1815                 }
1816
1817                 /*
1818                  * Deleted or updated by this transaction; forget it.
1819                  */
1820                 return NULL;
1821         }
1822
1823         /*
1824          * For UPDATE/DELETE we have to return tid of actual row we're
1825          * executing PQ for.
1826          */
1827         *tid = tuple.t_self;
1828
1829         /*
1830          * Need to run a recheck subquery.      Find or create a PQ stack entry.
1831          */
1832         epq = estate->es_evalPlanQual;
1833         endNode = true;
1834
1835         if (epq != NULL && epq->rti == 0)
1836         {
1837                 /* Top PQ stack entry is idle, so re-use it */
1838                 Assert(!(estate->es_useEvalPlan) && epq->next == NULL);
1839                 epq->rti = rti;
1840                 endNode = false;
1841         }
1842
1843         /*
1844          * If this is request for another RTE - Ra, - then we have to check
1845          * wasn't PlanQual requested for Ra already and if so then Ra' row was
1846          * updated again and we have to re-start old execution for Ra and
1847          * forget all what we done after Ra was suspended. Cool? -:))
1848          */
1849         if (epq != NULL && epq->rti != rti &&
1850                 epq->estate->es_evTuple[rti - 1] != NULL)
1851         {
1852                 do
1853                 {
1854                         evalPlanQual *oldepq;
1855
1856                         /* stop execution */
1857                         EvalPlanQualStop(epq);
1858                         /* pop previous PlanQual from the stack */
1859                         oldepq = epq->next;
1860                         Assert(oldepq && oldepq->rti != 0);
1861                         /* push current PQ to freePQ stack */
1862                         oldepq->free = epq;
1863                         epq = oldepq;
1864                         estate->es_evalPlanQual = epq;
1865                 } while (epq->rti != rti);
1866         }
1867
1868         /*
1869          * If we are requested for another RTE then we have to suspend
1870          * execution of current PlanQual and start execution for new one.
1871          */
1872         if (epq == NULL || epq->rti != rti)
1873         {
1874                 /* try to reuse plan used previously */
1875                 evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
1876
1877                 if (newepq == NULL)             /* first call or freePQ stack is empty */
1878                 {
1879                         newepq = (evalPlanQual *) palloc0(sizeof(evalPlanQual));
1880                         newepq->free = NULL;
1881                         newepq->estate = NULL;
1882                         newepq->planstate = NULL;
1883                 }
1884                 else
1885                 {
1886                         /* recycle previously used PlanQual */
1887                         Assert(newepq->estate == NULL);
1888                         epq->free = NULL;
1889                 }
1890                 /* push current PQ to the stack */
1891                 newepq->next = epq;
1892                 epq = newepq;
1893                 estate->es_evalPlanQual = epq;
1894                 epq->rti = rti;
1895                 endNode = false;
1896         }
1897
1898         Assert(epq->rti == rti);
1899
1900         /*
1901          * Ok - we're requested for the same RTE.  Unfortunately we still have
1902          * to end and restart execution of the plan, because ExecReScan
1903          * wouldn't ensure that upper plan nodes would reset themselves.  We
1904          * could make that work if insertion of the target tuple were
1905          * integrated with the Param mechanism somehow, so that the upper plan
1906          * nodes know that their children's outputs have changed.
1907          *
1908          * Note that the stack of free evalPlanQual nodes is quite useless at the
1909          * moment, since it only saves us from pallocing/releasing the
1910          * evalPlanQual nodes themselves.  But it will be useful once we
1911          * implement ReScan instead of end/restart for re-using PlanQual
1912          * nodes.
1913          */
1914         if (endNode)
1915         {
1916                 /* stop execution */
1917                 EvalPlanQualStop(epq);
1918         }
1919
1920         /*
1921          * Initialize new recheck query.
1922          *
1923          * Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
1924          * instead copy down changeable state from the top plan (including
1925          * es_result_relation_info, es_junkFilter) and reset locally
1926          * changeable state in the epq (including es_param_exec_vals,
1927          * es_evTupleNull).
1928          */
1929         EvalPlanQualStart(epq, estate, epq->next);
1930
1931         /*
1932          * free old RTE' tuple, if any, and store target tuple where
1933          * relation's scan node will see it
1934          */
1935         epqstate = epq->estate;
1936         if (epqstate->es_evTuple[rti - 1] != NULL)
1937                 heap_freetuple(epqstate->es_evTuple[rti - 1]);
1938         epqstate->es_evTuple[rti - 1] = copyTuple;
1939
1940         return EvalPlanQualNext(estate);
1941 }
1942
1943 static TupleTableSlot *
1944 EvalPlanQualNext(EState *estate)
1945 {
1946         evalPlanQual *epq = estate->es_evalPlanQual;
1947         MemoryContext oldcontext;
1948         TupleTableSlot *slot;
1949
1950         Assert(epq->rti != 0);
1951
1952 lpqnext:;
1953         oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
1954         slot = ExecProcNode(epq->planstate);
1955         MemoryContextSwitchTo(oldcontext);
1956
1957         /*
1958          * No more tuples for this PQ. Continue previous one.
1959          */
1960         if (TupIsNull(slot))
1961         {
1962                 evalPlanQual *oldepq;
1963
1964                 /* stop execution */
1965                 EvalPlanQualStop(epq);
1966                 /* pop old PQ from the stack */
1967                 oldepq = epq->next;
1968                 if (oldepq == NULL)
1969                 {
1970                         /* this is the first (oldest) PQ - mark as free */
1971                         epq->rti = 0;
1972                         estate->es_useEvalPlan = false;
1973                         /* and continue Query execution */
1974                         return (NULL);
1975                 }
1976                 Assert(oldepq->rti != 0);
1977                 /* push current PQ to freePQ stack */
1978                 oldepq->free = epq;
1979                 epq = oldepq;
1980                 estate->es_evalPlanQual = epq;
1981                 goto lpqnext;
1982         }
1983
1984         return (slot);
1985 }
1986
1987 static void
1988 EndEvalPlanQual(EState *estate)
1989 {
1990         evalPlanQual *epq = estate->es_evalPlanQual;
1991
1992         if (epq->rti == 0)                      /* plans already shutdowned */
1993         {
1994                 Assert(epq->next == NULL);
1995                 return;
1996         }
1997
1998         for (;;)
1999         {
2000                 evalPlanQual *oldepq;
2001
2002                 /* stop execution */
2003                 EvalPlanQualStop(epq);
2004                 /* pop old PQ from the stack */
2005                 oldepq = epq->next;
2006                 if (oldepq == NULL)
2007                 {
2008                         /* this is the first (oldest) PQ - mark as free */
2009                         epq->rti = 0;
2010                         estate->es_useEvalPlan = false;
2011                         break;
2012                 }
2013                 Assert(oldepq->rti != 0);
2014                 /* push current PQ to freePQ stack */
2015                 oldepq->free = epq;
2016                 epq = oldepq;
2017                 estate->es_evalPlanQual = epq;
2018         }
2019 }
2020
2021 /*
2022  * Start execution of one level of PlanQual.
2023  *
2024  * This is a cut-down version of ExecutorStart(): we copy some state from
2025  * the top-level estate rather than initializing it fresh.
2026  */
2027 static void
2028 EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
2029 {
2030         EState     *epqstate;
2031         int                     rtsize;
2032         MemoryContext oldcontext;
2033
2034         rtsize = length(estate->es_range_table);
2035
2036         epq->estate = epqstate = CreateExecutorState();
2037
2038         oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2039
2040         /*
2041          * The epqstates share the top query's copy of unchanging state such
2042          * as the snapshot, rangetable, result-rel info, and external Param
2043          * info. They need their own copies of local state, including a tuple
2044          * table, es_param_exec_vals, etc.
2045          */
2046         epqstate->es_direction = ForwardScanDirection;
2047         epqstate->es_snapshot = estate->es_snapshot;
2048         epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
2049         epqstate->es_range_table = estate->es_range_table;
2050         epqstate->es_result_relations = estate->es_result_relations;
2051         epqstate->es_num_result_relations = estate->es_num_result_relations;
2052         epqstate->es_result_relation_info = estate->es_result_relation_info;
2053         epqstate->es_junkFilter = estate->es_junkFilter;
2054         epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
2055         epqstate->es_param_list_info = estate->es_param_list_info;
2056         if (estate->es_topPlan->nParamExec > 0)
2057                 epqstate->es_param_exec_vals = (ParamExecData *)
2058                         palloc0(estate->es_topPlan->nParamExec * sizeof(ParamExecData));
2059         epqstate->es_rowMark = estate->es_rowMark;
2060         epqstate->es_instrument = estate->es_instrument;
2061         epqstate->es_force_oids = estate->es_force_oids;
2062         epqstate->es_topPlan = estate->es_topPlan;
2063
2064         /*
2065          * Each epqstate must have its own es_evTupleNull state, but all the
2066          * stack entries share es_evTuple state.  This allows sub-rechecks to
2067          * inherit the value being examined by an outer recheck.
2068          */
2069         epqstate->es_evTupleNull = (bool *) palloc0(rtsize * sizeof(bool));
2070         if (priorepq == NULL)
2071                 /* first PQ stack entry */
2072                 epqstate->es_evTuple = (HeapTuple *)
2073                         palloc0(rtsize * sizeof(HeapTuple));
2074         else
2075                 /* later stack entries share the same storage */
2076                 epqstate->es_evTuple = priorepq->estate->es_evTuple;
2077
2078         epqstate->es_tupleTable =
2079                 ExecCreateTupleTable(estate->es_tupleTable->size);
2080
2081         epq->planstate = ExecInitNode(estate->es_topPlan, epqstate);
2082
2083         MemoryContextSwitchTo(oldcontext);
2084 }
2085
2086 /*
2087  * End execution of one level of PlanQual.
2088  *
2089  * This is a cut-down version of ExecutorEnd(); basically we want to do most
2090  * of the normal cleanup, but *not* close result relations (which we are
2091  * just sharing from the outer query).
2092  */
2093 static void
2094 EvalPlanQualStop(evalPlanQual *epq)
2095 {
2096         EState     *epqstate = epq->estate;
2097         MemoryContext oldcontext;
2098
2099         oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
2100
2101         ExecEndNode(epq->planstate);
2102
2103         ExecDropTupleTable(epqstate->es_tupleTable, true);
2104         epqstate->es_tupleTable = NULL;
2105
2106         if (epqstate->es_evTuple[epq->rti - 1] != NULL)
2107         {
2108                 heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
2109                 epqstate->es_evTuple[epq->rti - 1] = NULL;
2110         }
2111
2112         MemoryContextSwitchTo(oldcontext);
2113
2114         FreeExecutorState(epqstate);
2115
2116         epq->estate = NULL;
2117         epq->planstate = NULL;
2118 }