PostgreSQL Source Code: src/backend/executor/nodeTidscan.c Source File

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nodeTidscan.c
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1/*-------------------------------------------------------------------------
2 *
3 * nodeTidscan.c
4 * Routines to support direct tid scans of relations
5 *
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/executor/nodeTidscan.c
12 *
13 *-------------------------------------------------------------------------
14 */
15/*
16 * INTERFACE ROUTINES
17 *
18 * ExecTidScan scans a relation using tids
19 * ExecInitTidScan creates and initializes state info.
20 * ExecReScanTidScan rescans the tid relation.
21 * ExecEndTidScan releases all storage.
22 */
23#include "postgres.h"
24
25#include "access/sysattr.h"
26#include "access/tableam.h"
27#include "catalog/pg_type.h"
28#include "executor/executor.h"
29#include "executor/nodeTidscan.h"
30#include "lib/qunique.h"
31#include "miscadmin.h"
32#include "nodes/nodeFuncs.h"
33#include "utils/array.h"
34#include "utils/rel.h"
35
36
37/*
38 * It's sufficient to check varattno to identify the CTID variable, as any
39 * Var in the relation scan qual must be for our table. (Even if it's a
40 * parameterized scan referencing some other table's CTID, the other table's
41 * Var would have become a Param by the time it gets here.)
42 */
43 #define IsCTIDVar(node) \
44 ((node) != NULL && \
45 IsA((node), Var) && \
46 ((Var *) (node))->varattno == SelfItemPointerAttributeNumber)
47
48/* one element in tss_tidexprs */
49 typedef struct TidExpr
50{
51 ExprState *exprstate; /* ExprState for a TID-yielding subexpr */
52 bool isarray; /* if true, it yields tid[] not just tid */
53 CurrentOfExpr *cexpr; /* alternatively, we can have CURRENT OF */
54 } TidExpr;
55
56static void TidExprListCreate(TidScanState *tidstate);
57static void TidListEval(TidScanState *tidstate);
58static int itemptr_comparator(const void *a, const void *b);
59static TupleTableSlot *TidNext(TidScanState *node);
60
61
62/*
63 * Extract the qual subexpressions that yield TIDs to search for,
64 * and compile them into ExprStates if they're ordinary expressions.
65 *
66 * CURRENT OF is a special case that we can't compile usefully;
67 * just drop it into the TidExpr list as-is.
68 */
69static void
70 TidExprListCreate(TidScanState *tidstate)
71{
72 TidScan *node = (TidScan *) tidstate->ss.ps.plan;
73 ListCell *l;
74
75 tidstate->tss_tidexprs = NIL;
76 tidstate->tss_isCurrentOf = false;
77
78 foreach(l, node->tidquals)
79 {
80 Expr *expr = (Expr *) lfirst(l);
81 TidExpr *tidexpr = (TidExpr *) palloc0(sizeof(TidExpr));
82
83 if (is_opclause(expr))
84 {
85 Node *arg1;
86 Node *arg2;
87
88 arg1 = get_leftop(expr);
89 arg2 = get_rightop(expr);
90 if (IsCTIDVar(arg1))
91 tidexpr->exprstate = ExecInitExpr((Expr *) arg2,
92 &tidstate->ss.ps);
93 else if (IsCTIDVar(arg2))
94 tidexpr->exprstate = ExecInitExpr((Expr *) arg1,
95 &tidstate->ss.ps);
96 else
97 elog(ERROR, "could not identify CTID variable");
98 tidexpr->isarray = false;
99 }
100 else if (expr && IsA(expr, ScalarArrayOpExpr))
101 {
102 ScalarArrayOpExpr *saex = (ScalarArrayOpExpr *) expr;
103
104 Assert(IsCTIDVar(linitial(saex->args)));
105 tidexpr->exprstate = ExecInitExpr(lsecond(saex->args),
106 &tidstate->ss.ps);
107 tidexpr->isarray = true;
108 }
109 else if (expr && IsA(expr, CurrentOfExpr))
110 {
111 CurrentOfExpr *cexpr = (CurrentOfExpr *) expr;
112
113 tidexpr->cexpr = cexpr;
114 tidstate->tss_isCurrentOf = true;
115 }
116 else
117 elog(ERROR, "could not identify CTID expression");
118
119 tidstate->tss_tidexprs = lappend(tidstate->tss_tidexprs, tidexpr);
120 }
121
122 /* CurrentOfExpr could never appear OR'd with something else */
123 Assert(list_length(tidstate->tss_tidexprs) == 1 ||
124 !tidstate->tss_isCurrentOf);
125}
126
127/*
128 * Compute the list of TIDs to be visited, by evaluating the expressions
129 * for them.
130 *
131 * (The result is actually an array, not a list.)
132 */
133static void
134 TidListEval(TidScanState *tidstate)
135{
136 ExprContext *econtext = tidstate->ss.ps.ps_ExprContext;
137 TableScanDesc scan;
138 ItemPointerData *tidList;
139 int numAllocTids;
140 int numTids;
141 ListCell *l;
142
143 /*
144 * Start scan on-demand - initializing a scan isn't free (e.g. heap stats
145 * the size of the table), so it makes sense to delay that until needed -
146 * the node might never get executed.
147 */
148 if (tidstate->ss.ss_currentScanDesc == NULL)
149 tidstate->ss.ss_currentScanDesc =
150 table_beginscan_tid(tidstate->ss.ss_currentRelation,
151 tidstate->ss.ps.state->es_snapshot);
152 scan = tidstate->ss.ss_currentScanDesc;
153
154 /*
155 * We initialize the array with enough slots for the case that all quals
156 * are simple OpExprs or CurrentOfExprs. If there are any
157 * ScalarArrayOpExprs, we may have to enlarge the array.
158 */
159 numAllocTids = list_length(tidstate->tss_tidexprs);
160 tidList = (ItemPointerData *)
161 palloc(numAllocTids * sizeof(ItemPointerData));
162 numTids = 0;
163
164 foreach(l, tidstate->tss_tidexprs)
165 {
166 TidExpr *tidexpr = (TidExpr *) lfirst(l);
167 ItemPointer itemptr;
168 bool isNull;
169
170 if (tidexpr->exprstate && !tidexpr->isarray)
171 {
172 itemptr = (ItemPointer)
173 DatumGetPointer(ExecEvalExprSwitchContext(tidexpr->exprstate,
174 econtext,
175 &isNull));
176 if (isNull)
177 continue;
178
179 /*
180 * We silently discard any TIDs that the AM considers invalid
181 * (E.g. for heap, they could be out of range at the time of scan
182 * start. Since we hold at least AccessShareLock on the table, it
183 * won't be possible for someone to truncate away the blocks we
184 * intend to visit.).
185 */
186 if (!table_tuple_tid_valid(scan, itemptr))
187 continue;
188
189 if (numTids >= numAllocTids)
190 {
191 numAllocTids *= 2;
192 tidList = (ItemPointerData *)
193 repalloc(tidList,
194 numAllocTids * sizeof(ItemPointerData));
195 }
196 tidList[numTids++] = *itemptr;
197 }
198 else if (tidexpr->exprstate && tidexpr->isarray)
199 {
200 Datum arraydatum;
201 ArrayType *itemarray;
202 Datum *ipdatums;
203 bool *ipnulls;
204 int ndatums;
205 int i;
206
207 arraydatum = ExecEvalExprSwitchContext(tidexpr->exprstate,
208 econtext,
209 &isNull);
210 if (isNull)
211 continue;
212 itemarray = DatumGetArrayTypeP(arraydatum);
213 deconstruct_array_builtin(itemarray, TIDOID, &ipdatums, &ipnulls, &ndatums);
214 if (numTids + ndatums > numAllocTids)
215 {
216 numAllocTids = numTids + ndatums;
217 tidList = (ItemPointerData *)
218 repalloc(tidList,
219 numAllocTids * sizeof(ItemPointerData));
220 }
221 for (i = 0; i < ndatums; i++)
222 {
223 if (ipnulls[i])
224 continue;
225
226 itemptr = (ItemPointer) DatumGetPointer(ipdatums[i]);
227
228 if (!table_tuple_tid_valid(scan, itemptr))
229 continue;
230
231 tidList[numTids++] = *itemptr;
232 }
233 pfree(ipdatums);
234 pfree(ipnulls);
235 }
236 else
237 {
238 ItemPointerData cursor_tid;
239
240 Assert(tidexpr->cexpr);
241 if (execCurrentOf(tidexpr->cexpr, econtext,
242 RelationGetRelid(tidstate->ss.ss_currentRelation),
243 &cursor_tid))
244 {
245 if (numTids >= numAllocTids)
246 {
247 numAllocTids *= 2;
248 tidList = (ItemPointerData *)
249 repalloc(tidList,
250 numAllocTids * sizeof(ItemPointerData));
251 }
252 tidList[numTids++] = cursor_tid;
253 }
254 }
255 }
256
257 /*
258 * Sort the array of TIDs into order, and eliminate duplicates.
259 * Eliminating duplicates is necessary since we want OR semantics across
260 * the list. Sorting makes it easier to detect duplicates, and as a bonus
261 * ensures that we will visit the heap in the most efficient way.
262 */
263 if (numTids > 1)
264 {
265 /* CurrentOfExpr could never appear OR'd with something else */
266 Assert(!tidstate->tss_isCurrentOf);
267
268 qsort(tidList, numTids, sizeof(ItemPointerData),
269 itemptr_comparator);
270 numTids = qunique(tidList, numTids, sizeof(ItemPointerData),
271 itemptr_comparator);
272 }
273
274 tidstate->tss_TidList = tidList;
275 tidstate->tss_NumTids = numTids;
276 tidstate->tss_TidPtr = -1;
277}
278
279/*
280 * qsort comparator for ItemPointerData items
281 */
282static int
283 itemptr_comparator(const void *a, const void *b)
284{
285 const ItemPointerData *ipa = (const ItemPointerData *) a;
286 const ItemPointerData *ipb = (const ItemPointerData *) b;
287 BlockNumber ba = ItemPointerGetBlockNumber(ipa);
288 BlockNumber bb = ItemPointerGetBlockNumber(ipb);
289 OffsetNumber oa = ItemPointerGetOffsetNumber(ipa);
290 OffsetNumber ob = ItemPointerGetOffsetNumber(ipb);
291
292 if (ba < bb)
293 return -1;
294 if (ba > bb)
295 return 1;
296 if (oa < ob)
297 return -1;
298 if (oa > ob)
299 return 1;
300 return 0;
301}
302
303/* ----------------------------------------------------------------
304 * TidNext
305 *
306 * Retrieve a tuple from the TidScan node's currentRelation
307 * using the tids in the TidScanState information.
308 *
309 * ----------------------------------------------------------------
310 */
311static TupleTableSlot *
312 TidNext(TidScanState *node)
313{
314 EState *estate;
315 ScanDirection direction;
316 Snapshot snapshot;
317 TableScanDesc scan;
318 Relation heapRelation;
319 TupleTableSlot *slot;
320 ItemPointerData *tidList;
321 int numTids;
322 bool bBackward;
323
324 /*
325 * extract necessary information from tid scan node
326 */
327 estate = node->ss.ps.state;
328 direction = estate->es_direction;
329 snapshot = estate->es_snapshot;
330 heapRelation = node->ss.ss_currentRelation;
331 slot = node->ss.ss_ScanTupleSlot;
332
333 /*
334 * First time through, compute the list of TIDs to be visited
335 */
336 if (node->tss_TidList == NULL)
337 TidListEval(node);
338
339 scan = node->ss.ss_currentScanDesc;
340 tidList = node->tss_TidList;
341 numTids = node->tss_NumTids;
342
343 /*
344 * Initialize or advance scan position, depending on direction.
345 */
346 bBackward = ScanDirectionIsBackward(direction);
347 if (bBackward)
348 {
349 if (node->tss_TidPtr < 0)
350 {
351 /* initialize for backward scan */
352 node->tss_TidPtr = numTids - 1;
353 }
354 else
355 node->tss_TidPtr--;
356 }
357 else
358 {
359 if (node->tss_TidPtr < 0)
360 {
361 /* initialize for forward scan */
362 node->tss_TidPtr = 0;
363 }
364 else
365 node->tss_TidPtr++;
366 }
367
368 while (node->tss_TidPtr >= 0 && node->tss_TidPtr < numTids)
369 {
370 ItemPointerData tid = tidList[node->tss_TidPtr];
371
372 /*
373 * For WHERE CURRENT OF, the tuple retrieved from the cursor might
374 * since have been updated; if so, we should fetch the version that is
375 * current according to our snapshot.
376 */
377 if (node->tss_isCurrentOf)
378 table_tuple_get_latest_tid(scan, &tid);
379
380 if (table_tuple_fetch_row_version(heapRelation, &tid, snapshot, slot))
381 return slot;
382
383 /* Bad TID or failed snapshot qual; try next */
384 if (bBackward)
385 node->tss_TidPtr--;
386 else
387 node->tss_TidPtr++;
388
389 CHECK_FOR_INTERRUPTS();
390 }
391
392 /*
393 * if we get here it means the tid scan failed so we are at the end of the
394 * scan..
395 */
396 return ExecClearTuple(slot);
397}
398
399/*
400 * TidRecheck -- access method routine to recheck a tuple in EvalPlanQual
401 */
402static bool
403 TidRecheck(TidScanState *node, TupleTableSlot *slot)
404{
405 ItemPointer match;
406
407 /* WHERE CURRENT OF always intends to resolve to the latest tuple */
408 if (node->tss_isCurrentOf)
409 return true;
410
411 if (node->tss_TidList == NULL)
412 TidListEval(node);
413
414 /*
415 * Binary search the TidList to see if this ctid is mentioned and return
416 * true if it is.
417 */
418 match = (ItemPointer) bsearch(&slot->tts_tid, node->tss_TidList,
419 node->tss_NumTids, sizeof(ItemPointerData),
420 itemptr_comparator);
421 return match != NULL;
422}
423
424
425/* ----------------------------------------------------------------
426 * ExecTidScan(node)
427 *
428 * Scans the relation using tids and returns
429 * the next qualifying tuple in the direction specified.
430 * We call the ExecScan() routine and pass it the appropriate
431 * access method functions.
432 *
433 * Conditions:
434 * -- the "cursor" maintained by the AMI is positioned at the tuple
435 * returned previously.
436 *
437 * Initial States:
438 * -- the relation indicated is opened for scanning so that the
439 * "cursor" is positioned before the first qualifying tuple.
440 * -- tss_TidPtr is -1.
441 * ----------------------------------------------------------------
442 */
443static TupleTableSlot *
444 ExecTidScan(PlanState *pstate)
445{
446 TidScanState *node = castNode(TidScanState, pstate);
447
448 return ExecScan(&node->ss,
449 (ExecScanAccessMtd) TidNext,
450 (ExecScanRecheckMtd) TidRecheck);
451}
452
453/* ----------------------------------------------------------------
454 * ExecReScanTidScan(node)
455 * ----------------------------------------------------------------
456 */
457void
458 ExecReScanTidScan(TidScanState *node)
459{
460 if (node->tss_TidList)
461 pfree(node->tss_TidList);
462 node->tss_TidList = NULL;
463 node->tss_NumTids = 0;
464 node->tss_TidPtr = -1;
465
466 /* not really necessary, but seems good form */
467 if (node->ss.ss_currentScanDesc)
468 table_rescan(node->ss.ss_currentScanDesc, NULL);
469
470 ExecScanReScan(&node->ss);
471}
472
473/* ----------------------------------------------------------------
474 * ExecEndTidScan
475 *
476 * Releases any storage allocated through C routines.
477 * Returns nothing.
478 * ----------------------------------------------------------------
479 */
480void
481 ExecEndTidScan(TidScanState *node)
482{
483 if (node->ss.ss_currentScanDesc)
484 table_endscan(node->ss.ss_currentScanDesc);
485}
486
487/* ----------------------------------------------------------------
488 * ExecInitTidScan
489 *
490 * Initializes the tid scan's state information, creates
491 * scan keys, and opens the base and tid relations.
492 *
493 * Parameters:
494 * node: TidScan node produced by the planner.
495 * estate: the execution state initialized in InitPlan.
496 * ----------------------------------------------------------------
497 */
498TidScanState *
499 ExecInitTidScan(TidScan *node, EState *estate, int eflags)
500{
501 TidScanState *tidstate;
502 Relation currentRelation;
503
504 /*
505 * create state structure
506 */
507 tidstate = makeNode(TidScanState);
508 tidstate->ss.ps.plan = (Plan *) node;
509 tidstate->ss.ps.state = estate;
510 tidstate->ss.ps.ExecProcNode = ExecTidScan;
511
512 /*
513 * Miscellaneous initialization
514 *
515 * create expression context for node
516 */
517 ExecAssignExprContext(estate, &tidstate->ss.ps);
518
519 /*
520 * mark tid list as not computed yet
521 */
522 tidstate->tss_TidList = NULL;
523 tidstate->tss_NumTids = 0;
524 tidstate->tss_TidPtr = -1;
525
526 /*
527 * open the scan relation
528 */
529 currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags);
530
531 tidstate->ss.ss_currentRelation = currentRelation;
532 tidstate->ss.ss_currentScanDesc = NULL; /* no heap scan here */
533
534 /*
535 * get the scan type from the relation descriptor.
536 */
537 ExecInitScanTupleSlot(estate, &tidstate->ss,
538 RelationGetDescr(currentRelation),
539 table_slot_callbacks(currentRelation));
540
541 /*
542 * Initialize result type and projection.
543 */
544 ExecInitResultTypeTL(&tidstate->ss.ps);
545 ExecAssignScanProjectionInfo(&tidstate->ss);
546
547 /*
548 * initialize child expressions
549 */
550 tidstate->ss.ps.qual =
551 ExecInitQual(node->scan.plan.qual, (PlanState *) tidstate);
552
553 TidExprListCreate(tidstate);
554
555 /*
556 * all done.
557 */
558 return tidstate;
559}
#define DatumGetArrayTypeP(X)
Definition: array.h:261
void deconstruct_array_builtin(ArrayType *array, Oid elmtype, Datum **elemsp, bool **nullsp, int *nelemsp)
Definition: arrayfuncs.c:3697
uint32 BlockNumber
Definition: block.h:31
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:226
bool execCurrentOf(CurrentOfExpr *cexpr, ExprContext *econtext, Oid table_oid, ItemPointer current_tid)
Definition: execCurrent.c:44
ExprState * ExecInitExpr(Expr *node, PlanState *parent)
Definition: execExpr.c:143
ExprState * ExecInitQual(List *qual, PlanState *parent)
Definition: execExpr.c:229
TupleTableSlot * ExecScan(ScanState *node, ExecScanAccessMtd accessMtd, ExecScanRecheckMtd recheckMtd)
Definition: execScan.c:47
void ExecAssignScanProjectionInfo(ScanState *node)
Definition: execScan.c:81
void ExecScanReScan(ScanState *node)
Definition: execScan.c:108
void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate, TupleDesc tupledesc, const TupleTableSlotOps *tts_ops)
Definition: execTuples.c:2000
void ExecInitResultTypeTL(PlanState *planstate)
Definition: execTuples.c:1944
void ExecAssignExprContext(EState *estate, PlanState *planstate)
Definition: execUtils.c:485
Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags)
Definition: execUtils.c:742
bool(* ExecScanRecheckMtd)(ScanState *node, TupleTableSlot *slot)
Definition: executor.h:577
TupleTableSlot *(* ExecScanAccessMtd)(ScanState *node)
Definition: executor.h:576
static Datum ExecEvalExprSwitchContext(ExprState *state, ExprContext *econtext, bool *isNull)
Definition: executor.h:433
Assert(PointerIsAligned(start, uint64))
b
int b
Definition: isn.c:74
a
int a
Definition: isn.c:73
i
int i
Definition: isn.c:77
static OffsetNumber ItemPointerGetOffsetNumber(const ItemPointerData *pointer)
Definition: itemptr.h:124
static BlockNumber ItemPointerGetBlockNumber(const ItemPointerData *pointer)
Definition: itemptr.h:103
ItemPointerData * ItemPointer
Definition: itemptr.h:49
List * lappend(List *list, void *datum)
Definition: list.c:339
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1610
void pfree(void *pointer)
Definition: mcxt.c:1594
void * palloc0(Size size)
Definition: mcxt.c:1395
void * palloc(Size size)
Definition: mcxt.c:1365
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122
static Node * get_rightop(const void *clause)
Definition: nodeFuncs.h:95
static bool is_opclause(const void *clause)
Definition: nodeFuncs.h:76
static Node * get_leftop(const void *clause)
Definition: nodeFuncs.h:83
static TupleTableSlot * ExecTidScan(PlanState *pstate)
Definition: nodeTidscan.c:444
static int itemptr_comparator(const void *a, const void *b)
Definition: nodeTidscan.c:283
TidScanState * ExecInitTidScan(TidScan *node, EState *estate, int eflags)
Definition: nodeTidscan.c:499
static bool TidRecheck(TidScanState *node, TupleTableSlot *slot)
Definition: nodeTidscan.c:403
void ExecEndTidScan(TidScanState *node)
Definition: nodeTidscan.c:481
void ExecReScanTidScan(TidScanState *node)
Definition: nodeTidscan.c:458
struct TidExpr TidExpr
static void TidListEval(TidScanState *tidstate)
Definition: nodeTidscan.c:134
#define IsCTIDVar(node)
Definition: nodeTidscan.c:43
static TupleTableSlot * TidNext(TidScanState *node)
Definition: nodeTidscan.c:312
static void TidExprListCreate(TidScanState *tidstate)
Definition: nodeTidscan.c:70
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
#define makeNode(_type_)
Definition: nodes.h:161
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
uint16 OffsetNumber
Definition: off.h:24
#define lfirst(lc)
Definition: pg_list.h:172
static int list_length(const List *l)
Definition: pg_list.h:152
#define NIL
Definition: pg_list.h:68
#define linitial(l)
Definition: pg_list.h:178
#define lsecond(l)
Definition: pg_list.h:183
#define qsort(a, b, c, d)
Definition: port.h:479
uint64_t Datum
Definition: postgres.h:70
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:322
static size_t qunique(void *array, size_t elements, size_t width, int(*compare)(const void *, const void *))
Definition: qunique.h:21
#define RelationGetRelid(relation)
Definition: rel.h:514
#define RelationGetDescr(relation)
Definition: rel.h:540
#define ScanDirectionIsBackward(direction)
Definition: sdir.h:50
ScanDirection
Definition: sdir.h:25
Definition: array.h:93
Definition: execnodes.h:655
ScanDirection es_direction
Definition: execnodes.h:659
Snapshot es_snapshot
Definition: execnodes.h:660
Definition: primnodes.h:189
Definition: nodes.h:135
ExprState * qual
Definition: execnodes.h:1180
Plan * plan
Definition: execnodes.h:1159
EState * state
Definition: execnodes.h:1161
ExprContext * ps_ExprContext
Definition: execnodes.h:1198
ExecProcNodeMtd ExecProcNode
Definition: execnodes.h:1165
Definition: plannodes.h:177
Definition: rel.h:56
Relation ss_currentRelation
Definition: execnodes.h:1616
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1618
PlanState ps
Definition: execnodes.h:1615
struct TableScanDescData * ss_currentScanDesc
Definition: execnodes.h:1617
Index scanrelid
Definition: plannodes.h:516
CurrentOfExpr * cexpr
Definition: nodeTidscan.c:53
ExprState * exprstate
Definition: nodeTidscan.c:51
bool isarray
Definition: nodeTidscan.c:52
int tss_TidPtr
Definition: execnodes.h:1916
ScanState ss
Definition: execnodes.h:1912
bool tss_isCurrentOf
Definition: execnodes.h:1914
ItemPointerData * tss_TidList
Definition: execnodes.h:1917
List * tss_tidexprs
Definition: execnodes.h:1913
int tss_NumTids
Definition: execnodes.h:1915
Scan scan
Definition: plannodes.h:699
List * tidquals
Definition: plannodes.h:701
ItemPointerData tts_tid
Definition: tuptable.h:129
void table_tuple_get_latest_tid(TableScanDesc scan, ItemPointer tid)
Definition: tableam.c:236
const TupleTableSlotOps * table_slot_callbacks(Relation relation)
Definition: tableam.c:59
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:985
static bool table_tuple_tid_valid(TableScanDesc scan, ItemPointer tid)
Definition: tableam.h:1279
static void table_rescan(TableScanDesc scan, ScanKeyData *key)
Definition: tableam.h:994
static bool table_tuple_fetch_row_version(Relation rel, ItemPointer tid, Snapshot snapshot, TupleTableSlot *slot)
Definition: tableam.h:1253
static TableScanDesc table_beginscan_tid(Relation rel, Snapshot snapshot)
Definition: tableam.h:961
static TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: tuptable.h:458
Definition: pg_list.h:46

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