execMain.c 34.5 KB
Newer Older
1 2 3
/*-------------------------------------------------------------------------
 *
 * execMain.c--
4
 *	  top level executor interface routines
5 6
 *
 * INTERFACE ROUTINES
7 8 9
 *	ExecutorStart()
 *	ExecutorRun()
 *	ExecutorEnd()
10
 *
11 12 13 14 15 16 17 18 19 20 21 22 23
 *	The old ExecutorMain() has been replaced by ExecutorStart(),
 *	ExecutorRun() and ExecutorEnd()
 *
 *	These three procedures are the external interfaces to the executor.
 *	In each case, the query descriptor and the execution state is required
 *	 as arguments
 *
 *	ExecutorStart() must be called at the beginning of any execution of any
 *	query plan and ExecutorEnd() should always be called at the end of
 *	execution of a plan.
 *
 *	ExecutorRun accepts 'feature' and 'count' arguments that specify whether
 *	the plan is to be executed forwards, backwards, and for how many tuples.
24 25 26 27 28
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
29
 *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.36 1998/01/05 03:31:06 momjian Exp $
30 31 32
 *
 *-------------------------------------------------------------------------
 */
33
#include <string.h>
34
#include "postgres.h"
35
#include "miscadmin.h"
36

37
#include "executor/executor.h"
38 39
#include "executor/execdefs.h"
#include "executor/execdebug.h"
40
#include "executor/nodeIndexscan.h"
41 42 43
#include "utils/builtins.h"
#include "utils/palloc.h"
#include "utils/acl.h"
44
#include "utils/syscache.h"
45
#include "utils/tqual.h"
46
#include "parser/parsetree.h"	/* rt_fetch() */
47
#include "storage/bufmgr.h"
Marc G. Fournier's avatar
Marc G. Fournier committed
48
#include "storage/lmgr.h"
49
#include "storage/smgr.h"
50 51 52
#include "commands/async.h"
/* #include "access/localam.h" */
#include "optimizer/var.h"
53 54
#include "access/heapam.h"
#include "catalog/heap.h"
55
#include "commands/trigger.h"
56

57 58 59


/* decls for local routines only used within this module */
60
static void
61 62
ExecCheckPerms(CmdType operation, int resultRelation, List *rangeTable,
			   Query *parseTree);
63
static TupleDesc
64 65 66
InitPlan(CmdType operation, Query *parseTree,
		 Plan *plan, EState *estate);
static void EndPlan(Plan *plan, EState *estate);
67
static TupleTableSlot *
68 69
ExecutePlan(EState *estate, Plan *plan,
			Query *parseTree, CmdType operation,
70 71
			int numberTuples, ScanDirection direction,
			void (*printfunc) ());
72 73
static void ExecRetrieve(TupleTableSlot *slot, void (*printfunc) (),
									 EState *estate);
74
static void
75 76
ExecAppend(TupleTableSlot *slot, ItemPointer tupleid,
		   EState *estate);
77
static void
78 79
ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
		   EState *estate);
80
static void
81 82
ExecReplace(TupleTableSlot *slot, ItemPointer tupleid,
			EState *estate, Query *parseTree);
83 84 85

/* end of local decls */

Marc G. Fournier's avatar
Marc G. Fournier committed
86
#ifdef QUERY_LIMIT
87
static int	queryLimit = ALL_TUPLES;
88

Marc G. Fournier's avatar
Marc G. Fournier committed
89 90 91
#undef ALL_TUPLES
#define ALL_TUPLES queryLimit

92 93
int ExecutorLimit(int limit);

Marc G. Fournier's avatar
Marc G. Fournier committed
94 95 96
int
ExecutorLimit(int limit)
{
97
	return queryLimit = limit;
Marc G. Fournier's avatar
Marc G. Fournier committed
98
}
99
#endif
Marc G. Fournier's avatar
Marc G. Fournier committed
100

101
/* ----------------------------------------------------------------
102 103 104 105 106 107 108
 *		ExecutorStart
 *
 *		This routine must be called at the beginning of any execution of any
 *		query plan
 *
 *		returns (AttrInfo*) which describes the attributes of the tuples to
 *		be returned by the query.
109 110 111 112
 *
 * ----------------------------------------------------------------
 */
TupleDesc
113
ExecutorStart(QueryDesc *queryDesc, EState *estate)
114
{
115
	TupleDesc	result;
116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135

	/* sanity checks */
	Assert(queryDesc != NULL);

	result = InitPlan(queryDesc->operation,
					  queryDesc->parsetree,
					  queryDesc->plantree,
					  estate);

	/*
	 * reset buffer refcount.  the current refcounts are saved and will be
	 * restored when ExecutorEnd is called
	 *
	 * this makes sure that when ExecutorRun's are called recursively as for
	 * postquel functions, the buffers pinned by one ExecutorRun will not
	 * be unpinned by another ExecutorRun.
	 */
	BufferRefCountReset(estate->es_refcount);

	return result;
136 137 138
}

/* ----------------------------------------------------------------
139 140 141 142 143 144 145
 *		ExecutorRun
 *
 *		This is the main routine of the executor module. It accepts
 *		the query descriptor from the traffic cop and executes the
 *		query plan.
 *
 *		ExecutorStart must have been called already.
146
 *
147 148 149 150 151 152
 *		the different features supported are:
 *			 EXEC_RUN:	retrieve all tuples in the forward direction
 *			 EXEC_FOR:	retrieve 'count' number of tuples in the forward dir
 *			 EXEC_BACK: retrieve 'count' number of tuples in the backward dir
 *			 EXEC_RETONE: return one tuple but don't 'retrieve' it
 *						   used in postquel function processing
153 154 155 156
 *
 *
 * ----------------------------------------------------------------
 */
157
TupleTableSlot *
158
ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
159
{
160 161 162
	CmdType		operation;
	Query	   *parseTree;
	Plan	   *plan;
163
	TupleTableSlot *result;
164 165
	CommandDest dest;
	void		(*destination) ();
166 167

	/* ----------------
168
	 *	sanity checks
169 170
	 * ----------------
	 */
171 172
	Assert(queryDesc != NULL);

173
	/* ----------------
174 175
	 *	extract information from the query descriptor
	 *	and the query feature.
176 177
	 * ----------------
	 */
178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
	operation = queryDesc->operation;
	parseTree = queryDesc->parsetree;
	plan = queryDesc->plantree;
	dest = queryDesc->dest;
	destination = (void (*) ()) DestToFunction(dest);
	estate->es_processed = 0;
	estate->es_lastoid = InvalidOid;

#if 0

	/*
	 * It doesn't work in common case (i.g. if function has a aggregate).
	 * Now we store parameter values before ExecutorStart. - vadim
	 * 01/22/97
	 */
#ifdef INDEXSCAN_PATCH

	/*
	 * If the plan is an index scan and some of the scan key are function
	 * arguments rescan the indices after the parameter values have been
	 * stored in the execution state.  DZ - 27-8-1996
	 */
	if ((nodeTag(plan) == T_IndexScan) &&
		(((IndexScan *) plan)->indxstate->iss_RuntimeKeyInfo != NULL))
	{
203
		ExprContext *econtext;
204 205 206 207 208 209 210 211 212 213

		econtext = ((IndexScan *) plan)->scan.scanstate->cstate.cs_ExprContext;
		ExecIndexReScan((IndexScan *) plan, econtext, plan);
	}
#endif
#endif

	switch (feature)
	{

214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231
		case EXEC_RUN:
			result = ExecutePlan(estate,
								 plan,
								 parseTree,
								 operation,
								 ALL_TUPLES,
								 ForwardScanDirection,
								 destination);
			break;
		case EXEC_FOR:
			result = ExecutePlan(estate,
								 plan,
								 parseTree,
								 operation,
								 count,
								 ForwardScanDirection,
								 destination);
			break;
232

233 234 235 236 237 238 239 240 241 242 243 244 245
			/* ----------------
			 *		retrieve next n "backward" tuples
			 * ----------------
			 */
		case EXEC_BACK:
			result = ExecutePlan(estate,
								 plan,
								 parseTree,
								 operation,
								 count,
								 BackwardScanDirection,
								 destination);
			break;
246

247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264
			/* ----------------
			 *		return one tuple but don't "retrieve" it.
			 *		(this is used by the rule manager..) -cim 9/14/89
			 * ----------------
			 */
		case EXEC_RETONE:
			result = ExecutePlan(estate,
								 plan,
								 parseTree,
								 operation,
								 ONE_TUPLE,
								 ForwardScanDirection,
								 destination);
			break;
		default:
			result = NULL;
			elog(DEBUG, "ExecutorRun: Unknown feature %d", feature);
			break;
265 266 267
	}

	return result;
268 269 270
}

/* ----------------------------------------------------------------
271 272 273 274 275 276 277
 *		ExecutorEnd
 *
 *		This routine must be called at the end of any execution of any
 *		query plan
 *
 *		returns (AttrInfo*) which describes the attributes of the tuples to
 *		be returned by the query.
278 279 280 281
 *
 * ----------------------------------------------------------------
 */
void
282
ExecutorEnd(QueryDesc *queryDesc, EState *estate)
283
{
284 285
	/* sanity checks */
	Assert(queryDesc != NULL);
286

287
	EndPlan(queryDesc->plantree, estate);
288

289 290
	/* restore saved refcounts. */
	BufferRefCountRestore(estate->es_refcount);
291 292 293 294
}

/* ===============================================================
 * ===============================================================
295
						 static routines follow
296 297 298 299 300 301
 * ===============================================================
 * ===============================================================
 */

static void
ExecCheckPerms(CmdType operation,
302
			   int resultRelation,
303 304
			   List *rangeTable,
			   Query *parseTree)
305
{
306 307 308 309 310 311 312 313 314 315 316
	int			i = 1;
	Oid			relid;
	HeapTuple	htp;
	List	   *lp;
	List	   *qvars,
			   *tvars;
	int32		ok = 1,
				aclcheck_result = -1;
	char	   *opstr;
	NameData	rname;
	char	   *userName;
317 318 319 320 321 322 323

#define CHECK(MODE)		pg_aclcheck(rname.data, userName, MODE)

	userName = GetPgUserName();

	foreach(lp, rangeTable)
	{
324
		RangeTblEntry *rte = lfirst(lp);
325 326 327 328 329 330

		relid = rte->relid;
		htp = SearchSysCacheTuple(RELOID,
								  ObjectIdGetDatum(relid),
								  0, 0, 0);
		if (!HeapTupleIsValid(htp))
331
			elog(ABORT, "ExecCheckPerms: bogus RT relid: %d",
332
				 relid);
333
		StrNCpy(rname.data,
334
				((Form_pg_class) GETSTRUCT(htp))->relname.data,
335
				NAMEDATALEN);
336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
		if (i == resultRelation)
		{						/* this is the result relation */
			qvars = pull_varnos(parseTree->qual);
			tvars = pull_varnos((Node *) parseTree->targetList);
			if (intMember(resultRelation, qvars) ||
				intMember(resultRelation, tvars))
			{
				/* result relation is scanned */
				ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
				opstr = "read";
				if (!ok)
					break;
			}
			switch (operation)
			{
351 352 353 354 355 356 357 358 359 360 361 362 363
				case CMD_INSERT:
					ok = ((aclcheck_result = CHECK(ACL_AP)) == ACLCHECK_OK) ||
						((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
					opstr = "append";
					break;
				case CMD_NOTIFY:		/* what does this mean?? -- jw,
										 * 1/6/94 */
				case CMD_DELETE:
				case CMD_UPDATE:
					ok = ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
					opstr = "write";
					break;
				default:
364
					elog(ABORT, "ExecCheckPerms: bogus operation %d",
365
						 operation);
366 367 368 369 370 371 372 373
			}
		}
		else
		{
			/* XXX NOTIFY?? */
			ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
			opstr = "read";
		}
374
		if (!ok)
375 376
			break;
		++i;
377 378
	}
	if (!ok)
379
	{
380
		elog(ABORT, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]);
381
	}
382 383 384 385
}


/* ----------------------------------------------------------------
386 387 388 389
 *		InitPlan
 *
 *		Initializes the query plan: open files, allocate storage
 *		and start up the rule manager
390 391
 * ----------------------------------------------------------------
 */
392
static TupleDesc
393
InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
394
{
395 396 397
	List	   *rangeTable;
	int			resultRelation;
	Relation	intoRelationDesc;
398

399 400 401
	TupleDesc	tupType;
	List	   *targetList;
	int			len;
402

403 404
	/* ----------------
	 *	get information from query descriptor
405 406
	 * ----------------
	 */
407 408
	rangeTable = parseTree->rtable;
	resultRelation = parseTree->resultRelation;
409 410

	/* ----------------
411
	 *	initialize the node's execution state
412 413
	 * ----------------
	 */
414 415
	estate->es_range_table = rangeTable;

416
	/* ----------------
417 418 419 420
	 *	initialize the BaseId counter so node base_id's
	 *	are assigned correctly.  Someday baseid's will have to
	 *	be stored someplace other than estate because they
	 *	should be unique per query planned.
421 422
	 * ----------------
	 */
423
	estate->es_BaseId = 1;
424

425 426 427 428
	/* ----------------
	 *	initialize result relation stuff
	 * ----------------
	 */
429

430 431
	if (resultRelation != 0 && operation != CMD_SELECT)
	{
432
		/* ----------------
433 434 435
		 *	  if we have a result relation, open it and

		 *	  initialize the result relation info stuff.
436 437
		 * ----------------
		 */
438 439 440 441 442
		RelationInfo *resultRelationInfo;
		Index		resultRelationIndex;
		RangeTblEntry *rtentry;
		Oid			resultRelationOid;
		Relation	resultRelationDesc;
443 444 445 446 447 448 449

		resultRelationIndex = resultRelation;
		rtentry = rt_fetch(resultRelationIndex, rangeTable);
		resultRelationOid = rtentry->relid;
		resultRelationDesc = heap_open(resultRelationOid);

		if (resultRelationDesc->rd_rel->relkind == RELKIND_SEQUENCE)
450
			elog(ABORT, "You can't change sequence relation %s",
451 452
				 resultRelationDesc->rd_rel->relname.data);

Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
453
		/*
454 455 456 457 458
		 * Write-lock the result relation right away: if the relation is
		 * used in a subsequent scan, we won't have to elevate the
		 * read-lock set by heap_beginscan to a write-lock (needed by
		 * heap_insert, heap_delete and heap_replace). This will hopefully
		 * prevent some deadlocks.	- 01/24/94
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
459
		 */
460 461 462 463 464 465 466 467
		RelationSetLockForWrite(resultRelationDesc);

		resultRelationInfo = makeNode(RelationInfo);
		resultRelationInfo->ri_RangeTableIndex = resultRelationIndex;
		resultRelationInfo->ri_RelationDesc = resultRelationDesc;
		resultRelationInfo->ri_NumIndices = 0;
		resultRelationInfo->ri_IndexRelationDescs = NULL;
		resultRelationInfo->ri_IndexRelationInfo = NULL;
468

469
		/* ----------------
470 471
		 *	open indices on result relation and save descriptors
		 *	in the result relation information..
472 473
		 * ----------------
		 */
474 475 476
		ExecOpenIndices(resultRelationOid, resultRelationInfo);

		estate->es_result_relation_info = resultRelationInfo;
477
	}
478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495
	else
	{
		/* ----------------
		 *		if no result relation, then set state appropriately
		 * ----------------
		 */
		estate->es_result_relation_info = NULL;
	}

#ifndef NO_SECURITY
	ExecCheckPerms(operation, resultRelation, rangeTable, parseTree);
#endif

	/* ----------------
	 *	  initialize the executor "tuple" table.
	 * ----------------
	 */
	{
496 497
		int			nSlots = ExecCountSlotsNode(plan);
		TupleTable	tupleTable = ExecCreateTupleTable(nSlots + 10);		/* why add ten? - jolly */
498

499 500
		estate->es_tupleTable = tupleTable;
	}
501

502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533
	/* ----------------
	 *	   initialize the private state information for
	 *	   all the nodes in the query tree.  This opens
	 *	   files, allocates storage and leaves us ready
	 *	   to start processing tuples..
	 * ----------------
	 */
	ExecInitNode(plan, estate, NULL);

	/* ----------------
	 *	   get the tuple descriptor describing the type
	 *	   of tuples to return.. (this is especially important
	 *	   if we are creating a relation with "retrieve into")
	 * ----------------
	 */
	tupType = ExecGetTupType(plan);		/* tuple descriptor */
	targetList = plan->targetlist;
	len = ExecTargetListLength(targetList);		/* number of attributes */

	/* ----------------
	 *	  now that we have the target list, initialize the junk filter
	 *	  if this is a REPLACE or a DELETE query.
	 *	  We also init the junk filter if this is an append query
	 *	  (there might be some rule lock info there...)
	 *	  NOTE: in the future we might want to initialize the junk
	 *	  filter for all queries.
	 * ----------------
	 */
	if (operation == CMD_UPDATE || operation == CMD_DELETE ||
		operation == CMD_INSERT)
	{

534
		JunkFilter *j = (JunkFilter *) ExecInitJunkFilter(targetList);
535 536 537 538 539 540 541 542 543 544 545 546 547 548

		estate->es_junkFilter = j;
	}
	else
		estate->es_junkFilter = NULL;

	/* ----------------
	 *	initialize the "into" relation
	 * ----------------
	 */
	intoRelationDesc = (Relation) NULL;

	if (operation == CMD_SELECT)
	{
549 550 551
		char	   *intoName;
		Oid			intoRelationId;
		TupleDesc	tupdesc;
552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574

		if (!parseTree->isPortal)
		{

			/*
			 * a select into table
			 */
			if (parseTree->into != NULL)
			{
				/* ----------------
				 *	create the "into" relation
				 * ----------------
				 */
				intoName = parseTree->into;

				/*
				 * have to copy tupType to get rid of constraints
				 */
				tupdesc = CreateTupleDescCopy(tupType);

				/* fixup to prevent zero-length columns in create */
				setVarAttrLenForCreateTable(tupdesc, targetList, rangeTable);

575
				intoRelationId = heap_create_with_catalog(intoName, tupdesc);
576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601
#ifdef NOT_USED					/* it's copy ... */
				resetVarAttrLenForCreateTable(tupdesc);
#endif
				FreeTupleDesc(tupdesc);

				/* ----------------
				 *	XXX rather than having to call setheapoverride(true)
				 *		and then back to false, we should change the
				 *		arguments to heap_open() instead..
				 * ----------------
				 */
				setheapoverride(true);

				intoRelationDesc = heap_open(intoRelationId);

				setheapoverride(false);
			}
		}
	}

	estate->es_into_relation_descriptor = intoRelationDesc;

	/* ----------------
	 *	return the type information..
	 * ----------------
	 */
602
/*
603 604 605
	attinfo = (AttrInfo *)palloc(sizeof(AttrInfo));
	attinfo->numAttr = len;
	attinfo->attrs = tupType->attrs;
606 607
*/

608
	return tupType;
609 610 611
}

/* ----------------------------------------------------------------
612 613 614
 *		EndPlan
 *
 *		Cleans up the query plan -- closes files and free up storages
615 616 617
 * ----------------------------------------------------------------
 */
static void
618
EndPlan(Plan *plan, EState *estate)
619
{
620 621
	RelationInfo *resultRelationInfo;
	Relation	intoRelationDesc;
622

623
	/* ----------------
624
	 *	get information from state
625 626
	 * ----------------
	 */
627 628 629 630 631 632 633 634 635 636 637 638 639 640
	resultRelationInfo = estate->es_result_relation_info;
	intoRelationDesc = estate->es_into_relation_descriptor;

	/* ----------------
	 *	 shut down the query
	 * ----------------
	 */
	ExecEndNode(plan, plan);

	/* ----------------
	 *	  destroy the executor "tuple" table.
	 * ----------------
	 */
	{
641
		TupleTable	tupleTable = (TupleTable) estate->es_tupleTable;
642 643 644 645 646 647 648 649 650 651 652

		ExecDestroyTupleTable(tupleTable, true);		/* was missing last arg */
		estate->es_tupleTable = NULL;
	}

	/* ----------------
	 *	 close the result relations if necessary
	 * ----------------
	 */
	if (resultRelationInfo != NULL)
	{
653
		Relation	resultRelationDesc;
654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672

		resultRelationDesc = resultRelationInfo->ri_RelationDesc;
		heap_close(resultRelationDesc);

		/* ----------------
		 *	close indices on the result relation
		 * ----------------
		 */
		ExecCloseIndices(resultRelationInfo);
	}

	/* ----------------
	 *	 close the "into" relation if necessary
	 * ----------------
	 */
	if (intoRelationDesc != NULL)
	{
		heap_close(intoRelationDesc);
	}
673 674 675
}

/* ----------------------------------------------------------------
676 677 678 679 680 681 682 683
 *		ExecutePlan
 *
 *		processes the query plan to retrieve 'tupleCount' tuples in the
 *		direction specified.
 *		Retrieves all tuples if tupleCount is 0
 *
 *		result is either a slot containing a tuple in the case
 *		of a RETRIEVE or NULL otherwise.
684 685 686 687 688 689 690 691
 *
 * ----------------------------------------------------------------
 */

/* the ctid attribute is a 'junk' attribute that is removed before the
   user can see it*/

static TupleTableSlot *
692 693 694
ExecutePlan(EState *estate,
			Plan *plan,
			Query *parseTree,
695 696 697 698
			CmdType operation,
			int numberTuples,
			ScanDirection direction,
			void (*printfunc) ())
699
{
700
	JunkFilter *junkfilter;
701 702

	TupleTableSlot *slot;
703
	ItemPointer tupleid = NULL;
704
	ItemPointerData tuple_ctid;
705
	int			current_tuple_count;
706 707
	TupleTableSlot *result;

708
	/* ----------------
709
	 *	initialize local variables
710 711
	 * ----------------
	 */
712 713 714 715
	slot = NULL;
	current_tuple_count = 0;
	result = NULL;

716
	/* ----------------
717
	 *	Set the direction.
718 719
	 * ----------------
	 */
720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763
	estate->es_direction = direction;

	/* ----------------
	 *	Loop until we've processed the proper number
	 *	of tuples from the plan..
	 * ----------------
	 */

	for (;;)
	{
		if (operation != CMD_NOTIFY)
		{
			/* ----------------
			 *	Execute the plan and obtain a tuple
			 * ----------------
			 */
			/* at the top level, the parent of a plan (2nd arg) is itself */
			slot = ExecProcNode(plan, plan);

			/* ----------------
			 *	if the tuple is null, then we assume
			 *	there is nothing more to process so
			 *	we just return null...
			 * ----------------
			 */
			if (TupIsNull(slot))
			{
				result = NULL;
				break;
			}
		}

		/* ----------------
		 *		if we have a junk filter, then project a new
		 *		tuple with the junk removed.
		 *
		 *		Store this new "clean" tuple in the place of the
		 *		original tuple.
		 *
		 *		Also, extract all the junk ifnormation we need.
		 * ----------------
		 */
		if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL)
		{
764
			Datum		datum;
765 766

/*			NameData	attrName; */
767 768
			HeapTuple	newTuple;
			bool		isNull;
769 770 771 772 773 774 775 776 777 778 779 780

			/* ---------------
			 * extract the 'ctid' junk attribute.
			 * ---------------
			 */
			if (operation == CMD_UPDATE || operation == CMD_DELETE)
			{
				if (!ExecGetJunkAttribute(junkfilter,
										  slot,
										  "ctid",
										  &datum,
										  &isNull))
781
					elog(ABORT, "ExecutePlan: NO (junk) `ctid' was found!");
782 783

				if (isNull)
784
					elog(ABORT, "ExecutePlan: (junk) `ctid' is NULL!");
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815

				tupleid = (ItemPointer) DatumGetPointer(datum);
				tuple_ctid = *tupleid;	/* make sure we don't free the
										 * ctid!! */
				tupleid = &tuple_ctid;
			}

			/* ---------------
			 * Finally create a new "clean" tuple with all junk attributes
			 * removed
			 * ---------------
			 */
			newTuple = ExecRemoveJunk(junkfilter, slot);

			slot = ExecStoreTuple(newTuple,		/* tuple to store */
								  slot, /* destination slot */
								  InvalidBuffer,		/* this tuple has no
														 * buffer */
								  true);		/* tuple should be pfreed */
		}						/* if (junkfilter... */

		/* ----------------
		 *		now that we have a tuple, do the appropriate thing
		 *		with it.. either return it to the user, add
		 *		it to a relation someplace, delete it from a
		 *		relation, or modify some of it's attributes.
		 * ----------------
		 */

		switch (operation)
		{
816 817 818 819 820 821
			case CMD_SELECT:
				ExecRetrieve(slot,		/* slot containing tuple */
							 printfunc, /* print function */
							 estate);	/* */
				result = slot;
				break;
822

823 824 825 826
			case CMD_INSERT:
				ExecAppend(slot, tupleid, estate);
				result = NULL;
				break;
827

828 829 830 831
			case CMD_DELETE:
				ExecDelete(slot, tupleid, estate);
				result = NULL;
				break;
832

833 834 835 836
			case CMD_UPDATE:
				ExecReplace(slot, tupleid, estate, parseTree);
				result = NULL;
				break;
837

838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854
				/*
				 * Total hack. I'm ignoring any accessor functions for
				 * Relation, RelationTupleForm, NameData. Assuming that
				 * NameData.data has offset 0.
				 */
			case CMD_NOTIFY:
				{
					RelationInfo *rInfo = estate->es_result_relation_info;
					Relation	rDesc = rInfo->ri_RelationDesc;

					Async_Notify(rDesc->rd_rel->relname.data);
					result = NULL;
					current_tuple_count = 0;
					numberTuples = 1;
					elog(DEBUG, "ExecNotify %s", &rDesc->rd_rel->relname);
				}
				break;
855

856 857
			default:
				elog(DEBUG, "ExecutePlan: unknown operation in queryDesc");
858
				result = NULL;
859
				break;
860 861 862 863 864 865 866 867 868 869
		}
		/* ----------------
		 *		check our tuple count.. if we've returned the
		 *		proper number then return, else loop again and
		 *		process more tuples..
		 * ----------------
		 */
		current_tuple_count += 1;
		if (numberTuples == current_tuple_count)
			break;
870
	}
871

872
	/* ----------------
873 874
	 *	here, result is either a slot containing a tuple in the case
	 *	of a RETRIEVE or NULL otherwise.
875 876
	 * ----------------
	 */
877
	return result;
878 879 880
}

/* ----------------------------------------------------------------
881
 *		ExecRetrieve
882
 *
883 884 885 886 887
 *		RETRIEVEs are easy.. we just pass the tuple to the appropriate
 *		print function.  The only complexity is when we do a
 *		"retrieve into", in which case we insert the tuple into
 *		the appropriate relation (note: this is a newly created relation
 *		so we don't need to worry about indices or locks.)
888 889 890
 * ----------------------------------------------------------------
 */
static void
891
ExecRetrieve(TupleTableSlot *slot,
892
			 void (*printfunc) (),
893
			 EState *estate)
894
{
895 896
	HeapTuple	tuple;
	TupleDesc	attrtype;
897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921

	/* ----------------
	 *	get the heap tuple out of the tuple table slot
	 * ----------------
	 */
	tuple = slot->val;
	attrtype = slot->ttc_tupleDescriptor;

	/* ----------------
	 *	insert the tuple into the "into relation"
	 * ----------------
	 */
	if (estate->es_into_relation_descriptor != NULL)
	{
		heap_insert(estate->es_into_relation_descriptor, tuple);
		IncrAppended();
	}

	/* ----------------
	 *	send the tuple to the front end (or the screen)
	 * ----------------
	 */
	(*printfunc) (tuple, attrtype);
	IncrRetrieved();
	(estate->es_processed)++;
922 923 924
}

/* ----------------------------------------------------------------
925
 *		ExecAppend
926
 *
927 928 929
 *		APPENDs are trickier.. we have to insert the tuple into
 *		the base relation and insert appropriate tuples into the
 *		index relations.
930 931 932 933
 * ----------------------------------------------------------------
 */

static void
934
ExecAppend(TupleTableSlot *slot,
935
		   ItemPointer tupleid,
936
		   EState *estate)
937
{
938 939 940 941 942
	HeapTuple	tuple;
	RelationInfo *resultRelationInfo;
	Relation	resultRelationDesc;
	int			numIndices;
	Oid			newId;
943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966

	/* ----------------
	 *	get the heap tuple out of the tuple table slot
	 * ----------------
	 */
	tuple = slot->val;

	/* ----------------
	 *	get information on the result relation
	 * ----------------
	 */
	resultRelationInfo = estate->es_result_relation_info;
	resultRelationDesc = resultRelationInfo->ri_RelationDesc;

	/* ----------------
	 *	have to add code to preform unique checking here.
	 *	cim -12/1/89
	 * ----------------
	 */

	/* BEFORE ROW INSERT Triggers */
	if (resultRelationDesc->trigdesc &&
	resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
	{
967
		HeapTuple	newtuple;
968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988

		newtuple = ExecBRInsertTriggers(resultRelationDesc, tuple);

		if (newtuple == NULL)	/* "do nothing" */
			return;

		if (newtuple != tuple)	/* modified by Trigger(s) */
		{
			Assert(slot->ttc_shouldFree);
			pfree(tuple);
			slot->val = tuple = newtuple;
		}
	}

	/* ----------------
	 * Check the constraints of a tuple
	 * ----------------
	 */

	if (resultRelationDesc->rd_att->constr)
	{
989
		HeapTuple	newtuple;
990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028

		newtuple = ExecConstraints("ExecAppend", resultRelationDesc, tuple);

		if (newtuple != tuple)	/* modified by DEFAULT */
		{
			Assert(slot->ttc_shouldFree);
			pfree(tuple);
			slot->val = tuple = newtuple;
		}
	}

	/* ----------------
	 *	insert the tuple
	 * ----------------
	 */
	newId = heap_insert(resultRelationDesc,		/* relation desc */
						tuple); /* heap tuple */
	IncrAppended();

	/* ----------------
	 *	process indices
	 *
	 *	Note: heap_insert adds a new tuple to a relation.  As a side
	 *	effect, the tupleid of the new tuple is placed in the new
	 *	tuple's t_ctid field.
	 * ----------------
	 */
	numIndices = resultRelationInfo->ri_NumIndices;
	if (numIndices > 0)
	{
		ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, false);
	}
	(estate->es_processed)++;
	estate->es_lastoid = newId;

	/* AFTER ROW INSERT Triggers */
	if (resultRelationDesc->trigdesc &&
	 resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0)
		ExecARInsertTriggers(resultRelationDesc, tuple);
1029 1030 1031
}

/* ----------------------------------------------------------------
1032
 *		ExecDelete
1033
 *
1034 1035
 *		DELETE is like append, we delete the tuple and its
 *		index tuples.
1036 1037 1038
 * ----------------------------------------------------------------
 */
static void
1039
ExecDelete(TupleTableSlot *slot,
1040
		   ItemPointer tupleid,
1041
		   EState *estate)
1042
{
1043 1044
	RelationInfo *resultRelationInfo;
	Relation	resultRelationDesc;
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056

	/* ----------------
	 *	get the result relation information
	 * ----------------
	 */
	resultRelationInfo = estate->es_result_relation_info;
	resultRelationDesc = resultRelationInfo->ri_RelationDesc;

	/* BEFORE ROW DELETE Triggers */
	if (resultRelationDesc->trigdesc &&
	resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
	{
1057
		bool		dodelete;
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091

		dodelete = ExecBRDeleteTriggers(resultRelationDesc, tupleid);

		if (!dodelete)			/* "do nothing" */
			return;
	}

	/* ----------------
	 *	delete the tuple
	 * ----------------
	 */
	if (heap_delete(resultRelationDesc, /* relation desc */
					tupleid))	/* item pointer to tuple */
		return;

	IncrDeleted();
	(estate->es_processed)++;

	/* ----------------
	 *	Note: Normally one would think that we have to
	 *		  delete index tuples associated with the
	 *		  heap tuple now..
	 *
	 *		  ... but in POSTGRES, we have no need to do this
	 *		  because the vacuum daemon automatically
	 *		  opens an index scan and deletes index tuples
	 *		  when it finds deleted heap tuples. -cim 9/27/89
	 * ----------------
	 */

	/* AFTER ROW DELETE Triggers */
	if (resultRelationDesc->trigdesc &&
	 resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0)
		ExecARDeleteTriggers(resultRelationDesc, tupleid);
1092 1093 1094 1095

}

/* ----------------------------------------------------------------
1096
 *		ExecReplace
1097
 *
1098 1099 1100 1101 1102 1103
 *		note: we can't run replace queries with transactions
 *		off because replaces are actually appends and our
 *		scan will mistakenly loop forever, replacing the tuple
 *		it just appended..	This should be fixed but until it
 *		is, we don't want to get stuck in an infinite loop
 *		which corrupts your database..
1104 1105 1106
 * ----------------------------------------------------------------
 */
static void
1107
ExecReplace(TupleTableSlot *slot,
1108
			ItemPointer tupleid,
1109 1110
			EState *estate,
			Query *parseTree)
1111
{
1112 1113 1114 1115
	HeapTuple	tuple;
	RelationInfo *resultRelationInfo;
	Relation	resultRelationDesc;
	int			numIndices;
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151

	/* ----------------
	 *	abort the operation if not running transactions
	 * ----------------
	 */
	if (IsBootstrapProcessingMode())
	{
		elog(DEBUG, "ExecReplace: replace can't run without transactions");
		return;
	}

	/* ----------------
	 *	get the heap tuple out of the tuple table slot
	 * ----------------
	 */
	tuple = slot->val;

	/* ----------------
	 *	get the result relation information
	 * ----------------
	 */
	resultRelationInfo = estate->es_result_relation_info;
	resultRelationDesc = resultRelationInfo->ri_RelationDesc;

	/* ----------------
	 *	have to add code to preform unique checking here.
	 *	in the event of unique tuples, this becomes a deletion
	 *	of the original tuple affected by the replace.
	 *	cim -12/1/89
	 * ----------------
	 */

	/* BEFORE ROW UPDATE Triggers */
	if (resultRelationDesc->trigdesc &&
	resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
	{
1152
		HeapTuple	newtuple;
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173

		newtuple = ExecBRUpdateTriggers(resultRelationDesc, tupleid, tuple);

		if (newtuple == NULL)	/* "do nothing" */
			return;

		if (newtuple != tuple)	/* modified by Trigger(s) */
		{
			Assert(slot->ttc_shouldFree);
			pfree(tuple);
			slot->val = tuple = newtuple;
		}
	}

	/* ----------------
	 * Check the constraints of a tuple
	 * ----------------
	 */

	if (resultRelationDesc->rd_att->constr)
	{
1174
		HeapTuple	newtuple;
1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235

		newtuple = ExecConstraints("ExecReplace", resultRelationDesc, tuple);

		if (newtuple != tuple)	/* modified by DEFAULT */
		{
			Assert(slot->ttc_shouldFree);
			pfree(tuple);
			slot->val = tuple = newtuple;
		}
	}

	/* ----------------
	 *	replace the heap tuple
	 *
	 * Don't want to continue if our heap_replace didn't actually
	 * do a replace. This would be the case if heap_replace
	 * detected a non-functional update. -kw 12/30/93
	 * ----------------
	 */
	if (heap_replace(resultRelationDesc,		/* relation desc */
					 tupleid,	/* item ptr of tuple to replace */
					 tuple))
	{							/* replacement heap tuple */
		return;
	}

	IncrReplaced();
	(estate->es_processed)++;

	/* ----------------
	 *	Note: instead of having to update the old index tuples
	 *		  associated with the heap tuple, all we do is form
	 *		  and insert new index tuples..  This is because
	 *		  replaces are actually deletes and inserts and
	 *		  index tuple deletion is done automagically by
	 *		  the vaccuum deamon.. All we do is insert new
	 *		  index tuples.  -cim 9/27/89
	 * ----------------
	 */

	/* ----------------
	 *	process indices
	 *
	 *	heap_replace updates a tuple in the base relation by invalidating
	 *	it and then appending a new tuple to the relation.	As a side
	 *	effect, the tupleid of the new tuple is placed in the new
	 *	tuple's t_ctid field.  So we now insert index tuples using
	 *	the new tupleid stored there.
	 * ----------------
	 */

	numIndices = resultRelationInfo->ri_NumIndices;
	if (numIndices > 0)
	{
		ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, true);
	}

	/* AFTER ROW UPDATE Triggers */
	if (resultRelationDesc->trigdesc &&
	 resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0)
		ExecARUpdateTriggers(resultRelationDesc, tupleid, tuple);
1236
}
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1237

1238
#if 0
1239
static HeapTuple
1240
ExecAttrDefault(Relation rel, HeapTuple tuple)
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1241
{
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253
	int			ndef = rel->rd_att->constr->num_defval;
	AttrDefault *attrdef = rel->rd_att->constr->defval;
	ExprContext *econtext = makeNode(ExprContext);
	HeapTuple	newtuple;
	Node	   *expr;
	bool		isnull;
	bool		isdone;
	Datum		val;
	Datum	   *replValue = NULL;
	char	   *replNull = NULL;
	char	   *repl = NULL;
	int			i;
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279

	econtext->ecxt_scantuple = NULL;	/* scan tuple slot */
	econtext->ecxt_innertuple = NULL;	/* inner tuple slot */
	econtext->ecxt_outertuple = NULL;	/* outer tuple slot */
	econtext->ecxt_relation = NULL;		/* relation */
	econtext->ecxt_relid = 0;	/* relid */
	econtext->ecxt_param_list_info = NULL;		/* param list info */
	econtext->ecxt_range_table = NULL;	/* range table */
	for (i = 0; i < ndef; i++)
	{
		if (!heap_attisnull(tuple, attrdef[i].adnum))
			continue;
		expr = (Node *) stringToNode(attrdef[i].adbin);

		val = ExecEvalExpr(expr, econtext, &isnull, &isdone);

		pfree(expr);

		if (isnull)
			continue;

		if (repl == NULL)
		{
			repl = (char *) palloc(rel->rd_att->natts * sizeof(char));
			replNull = (char *) palloc(rel->rd_att->natts * sizeof(char));
			replValue = (Datum *) palloc(rel->rd_att->natts * sizeof(Datum));
Bruce Momjian's avatar
Bruce Momjian committed
1280
			MemSet(repl, ' ', rel->rd_att->natts * sizeof(char));
1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
		}

		repl[attrdef[i].adnum - 1] = 'r';
		replNull[attrdef[i].adnum - 1] = ' ';
		replValue[attrdef[i].adnum - 1] = val;

	}

	pfree(econtext);

	if (repl == NULL)
		return (tuple);

	newtuple = heap_modifytuple(tuple, InvalidBuffer, rel, replValue, replNull, repl);

	pfree(repl);
	pfree(replNull);
	pfree(replValue);

	return (newtuple);

Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1302
}
1303
#endif
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1304

1305
static char *
1306
ExecRelCheck(Relation rel, HeapTuple tuple)
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1307
{
1308 1309 1310
	int			ncheck = rel->rd_att->constr->num_check;
	ConstrCheck *check = rel->rd_att->constr->check;
	ExprContext *econtext = makeNode(ExprContext);
1311
	TupleTableSlot *slot = makeNode(TupleTableSlot);
1312 1313 1314 1315 1316
	RangeTblEntry *rte = makeNode(RangeTblEntry);
	List	   *rtlist;
	List	   *qual;
	bool		res;
	int			i;
1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357

	slot->val = tuple;
	slot->ttc_shouldFree = false;
	slot->ttc_descIsNew = true;
	slot->ttc_tupleDescriptor = rel->rd_att;
	slot->ttc_buffer = InvalidBuffer;
	slot->ttc_whichplan = -1;
	rte->relname = nameout(&(rel->rd_rel->relname));
	rte->refname = rte->relname;
	rte->relid = rel->rd_id;
	rte->inh = false;
	rte->inFromCl = true;
	rtlist = lcons(rte, NIL);
	econtext->ecxt_scantuple = slot;	/* scan tuple slot */
	econtext->ecxt_innertuple = NULL;	/* inner tuple slot */
	econtext->ecxt_outertuple = NULL;	/* outer tuple slot */
	econtext->ecxt_relation = rel;		/* relation */
	econtext->ecxt_relid = 0;	/* relid */
	econtext->ecxt_param_list_info = NULL;		/* param list info */
	econtext->ecxt_range_table = rtlist;		/* range table */

	for (i = 0; i < ncheck; i++)
	{
		qual = (List *) stringToNode(check[i].ccbin);

		res = ExecQual(qual, econtext);

		pfree(qual);

		if (!res)
			return (check[i].ccname);
	}

	pfree(slot);
	pfree(rte->relname);
	pfree(rte);
	pfree(rtlist);
	pfree(econtext);

	return ((char *) NULL);

Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1358 1359 1360
}

HeapTuple
1361
ExecConstraints(char *caller, Relation rel, HeapTuple tuple)
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1362
{
1363
	HeapTuple	newtuple = tuple;
1364 1365 1366

	Assert(rel->rd_att->constr);

1367
#if 0
1368 1369
	if (rel->rd_att->constr->num_defval > 0)
		newtuple = tuple = ExecAttrDefault(rel, tuple);
1370
#endif
1371 1372

	if (rel->rd_att->constr->has_not_null)
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1373
	{
1374
		int			attrChk;
1375 1376 1377 1378

		for (attrChk = 1; attrChk <= rel->rd_att->natts; attrChk++)
		{
			if (rel->rd_att->attrs[attrChk - 1]->attnotnull && heap_attisnull(tuple, attrChk))
1379
				elog(ABORT, "%s: Fail to add null value in not null attribute %s",
1380 1381 1382 1383 1384 1385
				  caller, rel->rd_att->attrs[attrChk - 1]->attname.data);
		}
	}

	if (rel->rd_att->constr->num_check > 0)
	{
1386
		char	   *failed;
1387 1388

		if ((failed = ExecRelCheck(rel, tuple)) != NULL)
1389
			elog(ABORT, "%s: rejected due to CHECK constraint %s", caller, failed);
1390 1391 1392
	}

	return (newtuple);
Vadim B. Mikheev's avatar
Vadim B. Mikheev committed
1393
}