Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indexam.c
4 : * general index access method routines
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/access/index/indexam.c
12 : *
13 : * INTERFACE ROUTINES
14 : * index_open - open an index relation by relation OID
15 : * index_close - close an index relation
16 : * index_beginscan - start a scan of an index with amgettuple
17 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
18 : * index_rescan - restart a scan of an index
19 : * index_endscan - end a scan
20 : * index_insert - insert an index tuple into a relation
21 : * index_markpos - mark a scan position
22 : * index_restrpos - restore a scan position
23 : * index_parallelscan_estimate - estimate shared memory for parallel scan
24 : * index_parallelscan_initialize - initialize parallel scan
25 : * index_parallelrescan - (re)start a parallel scan of an index
26 : * index_beginscan_parallel - join parallel index scan
27 : * index_getnext_tid - get the next TID from a scan
28 : * index_fetch_heap - get the scan's next heap tuple
29 : * index_getnext_slot - get the next tuple from a scan
30 : * index_getbitmap - get all tuples from a scan
31 : * index_bulk_delete - bulk deletion of index tuples
32 : * index_vacuum_cleanup - post-deletion cleanup of an index
33 : * index_can_return - does index support index-only scans?
34 : * index_getprocid - get a support procedure OID
35 : * index_getprocinfo - get a support procedure's lookup info
36 : *
37 : * NOTES
38 : * This file contains the index_ routines which used
39 : * to be a scattered collection of stuff in access/genam.
40 : *
41 : *-------------------------------------------------------------------------
42 : */
43 :
44 : #include "postgres.h"
45 :
46 : #include "access/amapi.h"
47 : #include "access/relation.h"
48 : #include "access/reloptions.h"
49 : #include "access/relscan.h"
50 : #include "access/tableam.h"
51 : #include "catalog/index.h"
52 : #include "catalog/pg_type.h"
53 : #include "nodes/execnodes.h"
54 : #include "pgstat.h"
55 : #include "storage/lmgr.h"
56 : #include "storage/predicate.h"
57 : #include "utils/ruleutils.h"
58 : #include "utils/snapmgr.h"
59 : #include "utils/syscache.h"
60 :
61 :
62 : /* ----------------------------------------------------------------
63 : * macros used in index_ routines
64 : *
65 : * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
66 : * to check that we don't try to scan or do retail insertions into an index
67 : * that is currently being rebuilt or pending rebuild. This helps to catch
68 : * things that don't work when reindexing system catalogs, as well as prevent
69 : * user errors like index expressions that access their own tables. The check
70 : * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
71 : * when calling the index AM's ambuild routine, and there is no reason for
72 : * ambuild to call its subsidiary routines through this file.
73 : * ----------------------------------------------------------------
74 : */
75 : #define RELATION_CHECKS \
76 : do { \
77 : Assert(RelationIsValid(indexRelation)); \
78 : Assert(PointerIsValid(indexRelation->rd_indam)); \
79 : if (unlikely(ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))) \
80 : ereport(ERROR, \
81 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
82 : errmsg("cannot access index \"%s\" while it is being reindexed", \
83 : RelationGetRelationName(indexRelation)))); \
84 : } while(0)
85 :
86 : #define SCAN_CHECKS \
87 : ( \
88 : AssertMacro(IndexScanIsValid(scan)), \
89 : AssertMacro(RelationIsValid(scan->indexRelation)), \
90 : AssertMacro(PointerIsValid(scan->indexRelation->rd_indam)) \
91 : )
92 :
93 : #define CHECK_REL_PROCEDURE(pname) \
94 : do { \
95 : if (indexRelation->rd_indam->pname == NULL) \
96 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
97 : CppAsString(pname), RelationGetRelationName(indexRelation)); \
98 : } while(0)
99 :
100 : #define CHECK_SCAN_PROCEDURE(pname) \
101 : do { \
102 : if (scan->indexRelation->rd_indam->pname == NULL) \
103 : elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
104 : CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
105 : } while(0)
106 :
107 : static IndexScanDesc index_beginscan_internal(Relation indexRelation,
108 : int nkeys, int norderbys, Snapshot snapshot,
109 : ParallelIndexScanDesc pscan, bool temp_snap);
110 : static inline void validate_relation_kind(Relation r);
111 :
112 :
113 : /* ----------------------------------------------------------------
114 : * index_ interface functions
115 : * ----------------------------------------------------------------
116 : */
117 :
118 : /* ----------------
119 : * index_open - open an index relation by relation OID
120 : *
121 : * If lockmode is not "NoLock", the specified kind of lock is
122 : * obtained on the index. (Generally, NoLock should only be
123 : * used if the caller knows it has some appropriate lock on the
124 : * index already.)
125 : *
126 : * An error is raised if the index does not exist.
127 : *
128 : * This is a convenience routine adapted for indexscan use.
129 : * Some callers may prefer to use relation_open directly.
130 : * ----------------
131 : */
132 : Relation
133 18375416 : index_open(Oid relationId, LOCKMODE lockmode)
134 : {
135 : Relation r;
136 :
137 18375416 : r = relation_open(relationId, lockmode);
138 :
139 18375402 : validate_relation_kind(r);
140 :
141 18375380 : return r;
142 : }
143 :
144 : /* ----------------
145 : * try_index_open - open an index relation by relation OID
146 : *
147 : * Same as index_open, except return NULL instead of failing
148 : * if the relation does not exist.
149 : * ----------------
150 : */
151 : Relation
152 2132 : try_index_open(Oid relationId, LOCKMODE lockmode)
153 : {
154 : Relation r;
155 :
156 2132 : r = try_relation_open(relationId, lockmode);
157 :
158 : /* leave if index does not exist */
159 2132 : if (!r)
160 0 : return NULL;
161 :
162 2132 : validate_relation_kind(r);
163 :
164 2132 : return r;
165 : }
166 :
167 : /* ----------------
168 : * index_close - close an index relation
169 : *
170 : * If lockmode is not "NoLock", we then release the specified lock.
171 : *
172 : * Note that it is often sensible to hold a lock beyond index_close;
173 : * in that case, the lock is released automatically at xact end.
174 : * ----------------
175 : */
176 : void
177 18409226 : index_close(Relation relation, LOCKMODE lockmode)
178 : {
179 18409226 : LockRelId relid = relation->rd_lockInfo.lockRelId;
180 :
181 : Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
182 :
183 : /* The relcache does the real work... */
184 18409226 : RelationClose(relation);
185 :
186 18409226 : if (lockmode != NoLock)
187 16864128 : UnlockRelationId(&relid, lockmode);
188 18409226 : }
189 :
190 : /* ----------------
191 : * validate_relation_kind - check the relation's kind
192 : *
193 : * Make sure relkind is an index or a partitioned index.
194 : * ----------------
195 : */
196 : static inline void
197 18377534 : validate_relation_kind(Relation r)
198 : {
199 18377534 : if (r->rd_rel->relkind != RELKIND_INDEX &&
200 10948 : r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
201 22 : ereport(ERROR,
202 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
203 : errmsg("\"%s\" is not an index",
204 : RelationGetRelationName(r))));
205 18377512 : }
206 :
207 :
208 : /* ----------------
209 : * index_insert - insert an index tuple into a relation
210 : * ----------------
211 : */
212 : bool
213 8384084 : index_insert(Relation indexRelation,
214 : Datum *values,
215 : bool *isnull,
216 : ItemPointer heap_t_ctid,
217 : Relation heapRelation,
218 : IndexUniqueCheck checkUnique,
219 : bool indexUnchanged,
220 : IndexInfo *indexInfo)
221 : {
222 8384084 : RELATION_CHECKS;
223 8384084 : CHECK_REL_PROCEDURE(aminsert);
224 :
225 8384084 : if (!(indexRelation->rd_indam->ampredlocks))
226 576918 : CheckForSerializableConflictIn(indexRelation,
227 : (ItemPointer) NULL,
228 : InvalidBlockNumber);
229 :
230 8384084 : return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
231 : heap_t_ctid, heapRelation,
232 : checkUnique, indexUnchanged,
233 : indexInfo);
234 : }
235 :
236 : /* -------------------------
237 : * index_insert_cleanup - clean up after all index inserts are done
238 : * -------------------------
239 : */
240 : void
241 3262396 : index_insert_cleanup(Relation indexRelation,
242 : IndexInfo *indexInfo)
243 : {
244 3262396 : RELATION_CHECKS;
245 :
246 3262396 : if (indexRelation->rd_indam->aminsertcleanup)
247 1154 : indexRelation->rd_indam->aminsertcleanup(indexRelation, indexInfo);
248 3262396 : }
249 :
250 : /*
251 : * index_beginscan - start a scan of an index with amgettuple
252 : *
253 : * Caller must be holding suitable locks on the heap and the index.
254 : */
255 : IndexScanDesc
256 13753744 : index_beginscan(Relation heapRelation,
257 : Relation indexRelation,
258 : Snapshot snapshot,
259 : IndexScanInstrumentation *instrument,
260 : int nkeys, int norderbys)
261 : {
262 : IndexScanDesc scan;
263 :
264 : Assert(snapshot != InvalidSnapshot);
265 :
266 13753744 : scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
267 :
268 : /*
269 : * Save additional parameters into the scandesc. Everything else was set
270 : * up by RelationGetIndexScan.
271 : */
272 13753744 : scan->heapRelation = heapRelation;
273 13753744 : scan->xs_snapshot = snapshot;
274 13753744 : scan->instrument = instrument;
275 :
276 : /* prepare to fetch index matches from table */
277 13753744 : scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
278 :
279 13753744 : return scan;
280 : }
281 :
282 : /*
283 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
284 : *
285 : * As above, caller had better be holding some lock on the parent heap
286 : * relation, even though it's not explicitly mentioned here.
287 : */
288 : IndexScanDesc
289 23146 : index_beginscan_bitmap(Relation indexRelation,
290 : Snapshot snapshot,
291 : IndexScanInstrumentation *instrument,
292 : int nkeys)
293 : {
294 : IndexScanDesc scan;
295 :
296 : Assert(snapshot != InvalidSnapshot);
297 :
298 23146 : scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
299 :
300 : /*
301 : * Save additional parameters into the scandesc. Everything else was set
302 : * up by RelationGetIndexScan.
303 : */
304 23146 : scan->xs_snapshot = snapshot;
305 23146 : scan->instrument = instrument;
306 :
307 23146 : return scan;
308 : }
309 :
310 : /*
311 : * index_beginscan_internal --- common code for index_beginscan variants
312 : */
313 : static IndexScanDesc
314 13777280 : index_beginscan_internal(Relation indexRelation,
315 : int nkeys, int norderbys, Snapshot snapshot,
316 : ParallelIndexScanDesc pscan, bool temp_snap)
317 : {
318 : IndexScanDesc scan;
319 :
320 13777280 : RELATION_CHECKS;
321 13777280 : CHECK_REL_PROCEDURE(ambeginscan);
322 :
323 13777280 : if (!(indexRelation->rd_indam->ampredlocks))
324 4624 : PredicateLockRelation(indexRelation, snapshot);
325 :
326 : /*
327 : * We hold a reference count to the relcache entry throughout the scan.
328 : */
329 13777280 : RelationIncrementReferenceCount(indexRelation);
330 :
331 : /*
332 : * Tell the AM to open a scan.
333 : */
334 13777280 : scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
335 : norderbys);
336 : /* Initialize information for parallel scan. */
337 13777280 : scan->parallel_scan = pscan;
338 13777280 : scan->xs_temp_snap = temp_snap;
339 :
340 13777280 : return scan;
341 : }
342 :
343 : /* ----------------
344 : * index_rescan - (re)start a scan of an index
345 : *
346 : * During a restart, the caller may specify a new set of scankeys and/or
347 : * orderbykeys; but the number of keys cannot differ from what index_beginscan
348 : * was told. (Later we might relax that to "must not exceed", but currently
349 : * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
350 : * To restart the scan without changing keys, pass NULL for the key arrays.
351 : * (Of course, keys *must* be passed on the first call, unless
352 : * scan->numberOfKeys is zero.)
353 : * ----------------
354 : */
355 : void
356 14438436 : index_rescan(IndexScanDesc scan,
357 : ScanKey keys, int nkeys,
358 : ScanKey orderbys, int norderbys)
359 : {
360 : SCAN_CHECKS;
361 14438436 : CHECK_SCAN_PROCEDURE(amrescan);
362 :
363 : Assert(nkeys == scan->numberOfKeys);
364 : Assert(norderbys == scan->numberOfOrderBys);
365 :
366 : /* Release resources (like buffer pins) from table accesses */
367 14438436 : if (scan->xs_heapfetch)
368 14411416 : table_index_fetch_reset(scan->xs_heapfetch);
369 :
370 14438436 : scan->kill_prior_tuple = false; /* for safety */
371 14438436 : scan->xs_heap_continue = false;
372 :
373 14438436 : scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
374 : orderbys, norderbys);
375 14438436 : }
376 :
377 : /* ----------------
378 : * index_endscan - end a scan
379 : * ----------------
380 : */
381 : void
382 13775492 : index_endscan(IndexScanDesc scan)
383 : {
384 : SCAN_CHECKS;
385 13775492 : CHECK_SCAN_PROCEDURE(amendscan);
386 :
387 : /* Release resources (like buffer pins) from table accesses */
388 13775492 : if (scan->xs_heapfetch)
389 : {
390 13752448 : table_index_fetch_end(scan->xs_heapfetch);
391 13752448 : scan->xs_heapfetch = NULL;
392 : }
393 :
394 : /* End the AM's scan */
395 13775492 : scan->indexRelation->rd_indam->amendscan(scan);
396 :
397 : /* Release index refcount acquired by index_beginscan */
398 13775492 : RelationDecrementReferenceCount(scan->indexRelation);
399 :
400 13775492 : if (scan->xs_temp_snap)
401 390 : UnregisterSnapshot(scan->xs_snapshot);
402 :
403 : /* Release the scan data structure itself */
404 13775492 : IndexScanEnd(scan);
405 13775492 : }
406 :
407 : /* ----------------
408 : * index_markpos - mark a scan position
409 : * ----------------
410 : */
411 : void
412 130074 : index_markpos(IndexScanDesc scan)
413 : {
414 : SCAN_CHECKS;
415 130074 : CHECK_SCAN_PROCEDURE(ammarkpos);
416 :
417 130074 : scan->indexRelation->rd_indam->ammarkpos(scan);
418 130074 : }
419 :
420 : /* ----------------
421 : * index_restrpos - restore a scan position
422 : *
423 : * NOTE: this only restores the internal scan state of the index AM. See
424 : * comments for ExecRestrPos().
425 : *
426 : * NOTE: For heap, in the presence of HOT chains, mark/restore only works
427 : * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
428 : * most one returnable tuple in each HOT chain, and so restoring the prior
429 : * state at the granularity of the index AM is sufficient. Since the only
430 : * current user of mark/restore functionality is nodeMergejoin.c, this
431 : * effectively means that merge-join plans only work for MVCC snapshots. This
432 : * could be fixed if necessary, but for now it seems unimportant.
433 : * ----------------
434 : */
435 : void
436 54018 : index_restrpos(IndexScanDesc scan)
437 : {
438 : Assert(IsMVCCSnapshot(scan->xs_snapshot));
439 :
440 : SCAN_CHECKS;
441 54018 : CHECK_SCAN_PROCEDURE(amrestrpos);
442 :
443 : /* release resources (like buffer pins) from table accesses */
444 54018 : if (scan->xs_heapfetch)
445 54018 : table_index_fetch_reset(scan->xs_heapfetch);
446 :
447 54018 : scan->kill_prior_tuple = false; /* for safety */
448 54018 : scan->xs_heap_continue = false;
449 :
450 54018 : scan->indexRelation->rd_indam->amrestrpos(scan);
451 54018 : }
452 :
453 : /*
454 : * index_parallelscan_estimate - estimate shared memory for parallel scan
455 : *
456 : * When instrument=true, estimate includes SharedIndexScanInstrumentation
457 : * space. When parallel_aware=true, estimate includes whatever space the
458 : * index AM's amestimateparallelscan routine requested when called.
459 : */
460 : Size
461 334 : index_parallelscan_estimate(Relation indexRelation, int nkeys, int norderbys,
462 : Snapshot snapshot, bool instrument,
463 : bool parallel_aware, int nworkers)
464 : {
465 : Size nbytes;
466 :
467 : Assert(instrument || parallel_aware);
468 :
469 334 : RELATION_CHECKS;
470 :
471 334 : nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
472 334 : nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
473 334 : nbytes = MAXALIGN(nbytes);
474 :
475 334 : if (instrument)
476 : {
477 : Size sharedinfosz;
478 :
479 270 : sharedinfosz = offsetof(SharedIndexScanInstrumentation, winstrument) +
480 : nworkers * sizeof(IndexScanInstrumentation);
481 270 : nbytes = add_size(nbytes, sharedinfosz);
482 270 : nbytes = MAXALIGN(nbytes);
483 : }
484 :
485 : /*
486 : * If parallel scan index AM interface can't be used (or index AM provides
487 : * no such interface), assume there is no AM-specific data needed
488 : */
489 334 : if (parallel_aware &&
490 64 : indexRelation->rd_indam->amestimateparallelscan != NULL)
491 64 : nbytes = add_size(nbytes,
492 64 : indexRelation->rd_indam->amestimateparallelscan(nkeys,
493 : norderbys));
494 :
495 334 : return nbytes;
496 : }
497 :
498 : /*
499 : * index_parallelscan_initialize - initialize parallel scan
500 : *
501 : * We initialize both the ParallelIndexScanDesc proper and the AM-specific
502 : * information which follows it.
503 : *
504 : * This function calls access method specific initialization routine to
505 : * initialize am specific information. Call this just once in the leader
506 : * process; then, individual workers attach via index_beginscan_parallel.
507 : */
508 : void
509 334 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
510 : Snapshot snapshot, bool instrument,
511 : bool parallel_aware, int nworkers,
512 : SharedIndexScanInstrumentation **sharedinfo,
513 : ParallelIndexScanDesc target)
514 : {
515 : Size offset;
516 :
517 : Assert(instrument || parallel_aware);
518 :
519 334 : RELATION_CHECKS;
520 :
521 334 : offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
522 : EstimateSnapshotSpace(snapshot));
523 334 : offset = MAXALIGN(offset);
524 :
525 334 : target->ps_locator = heapRelation->rd_locator;
526 334 : target->ps_indexlocator = indexRelation->rd_locator;
527 334 : target->ps_offset_ins = 0;
528 334 : target->ps_offset_am = 0;
529 334 : SerializeSnapshot(snapshot, target->ps_snapshot_data);
530 :
531 334 : if (instrument)
532 : {
533 : Size sharedinfosz;
534 :
535 270 : target->ps_offset_ins = offset;
536 270 : sharedinfosz = offsetof(SharedIndexScanInstrumentation, winstrument) +
537 : nworkers * sizeof(IndexScanInstrumentation);
538 270 : offset = add_size(offset, sharedinfosz);
539 270 : offset = MAXALIGN(offset);
540 :
541 : /* Set leader's *sharedinfo pointer, and initialize stats */
542 270 : *sharedinfo = (SharedIndexScanInstrumentation *)
543 270 : OffsetToPointer(target, target->ps_offset_ins);
544 270 : memset(*sharedinfo, 0, sharedinfosz);
545 270 : (*sharedinfo)->num_workers = nworkers;
546 : }
547 :
548 : /* aminitparallelscan is optional; assume no-op if not provided by AM */
549 334 : if (parallel_aware && indexRelation->rd_indam->aminitparallelscan != NULL)
550 : {
551 : void *amtarget;
552 :
553 64 : target->ps_offset_am = offset;
554 64 : amtarget = OffsetToPointer(target, target->ps_offset_am);
555 64 : indexRelation->rd_indam->aminitparallelscan(amtarget);
556 : }
557 334 : }
558 :
559 : /* ----------------
560 : * index_parallelrescan - (re)start a parallel scan of an index
561 : * ----------------
562 : */
563 : void
564 24 : index_parallelrescan(IndexScanDesc scan)
565 : {
566 : SCAN_CHECKS;
567 :
568 24 : if (scan->xs_heapfetch)
569 24 : table_index_fetch_reset(scan->xs_heapfetch);
570 :
571 : /* amparallelrescan is optional; assume no-op if not provided by AM */
572 24 : if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
573 24 : scan->indexRelation->rd_indam->amparallelrescan(scan);
574 24 : }
575 :
576 : /*
577 : * index_beginscan_parallel - join parallel index scan
578 : *
579 : * Caller must be holding suitable locks on the heap and the index.
580 : */
581 : IndexScanDesc
582 390 : index_beginscan_parallel(Relation heaprel, Relation indexrel,
583 : IndexScanInstrumentation *instrument,
584 : int nkeys, int norderbys,
585 : ParallelIndexScanDesc pscan)
586 : {
587 : Snapshot snapshot;
588 : IndexScanDesc scan;
589 :
590 : Assert(RelFileLocatorEquals(heaprel->rd_locator, pscan->ps_locator));
591 : Assert(RelFileLocatorEquals(indexrel->rd_locator, pscan->ps_indexlocator));
592 :
593 390 : snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
594 390 : RegisterSnapshot(snapshot);
595 390 : scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
596 : pscan, true);
597 :
598 : /*
599 : * Save additional parameters into the scandesc. Everything else was set
600 : * up by index_beginscan_internal.
601 : */
602 390 : scan->heapRelation = heaprel;
603 390 : scan->xs_snapshot = snapshot;
604 390 : scan->instrument = instrument;
605 :
606 : /* prepare to fetch index matches from table */
607 390 : scan->xs_heapfetch = table_index_fetch_begin(heaprel);
608 :
609 390 : return scan;
610 : }
611 :
612 : /* ----------------
613 : * index_getnext_tid - get the next TID from a scan
614 : *
615 : * The result is the next TID satisfying the scan keys,
616 : * or NULL if no more matching tuples exist.
617 : * ----------------
618 : */
619 : ItemPointer
620 34364108 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
621 : {
622 : bool found;
623 :
624 : SCAN_CHECKS;
625 34364108 : CHECK_SCAN_PROCEDURE(amgettuple);
626 :
627 : /* XXX: we should assert that a snapshot is pushed or registered */
628 : Assert(TransactionIdIsValid(RecentXmin));
629 :
630 : /*
631 : * The AM's amgettuple proc finds the next index entry matching the scan
632 : * keys, and puts the TID into scan->xs_heaptid. It should also set
633 : * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
634 : * pay no attention to those fields here.
635 : */
636 34364108 : found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
637 :
638 : /* Reset kill flag immediately for safety */
639 34364108 : scan->kill_prior_tuple = false;
640 34364108 : scan->xs_heap_continue = false;
641 :
642 : /* If we're out of index entries, we're done */
643 34364108 : if (!found)
644 : {
645 : /* release resources (like buffer pins) from table accesses */
646 6503884 : if (scan->xs_heapfetch)
647 6503884 : table_index_fetch_reset(scan->xs_heapfetch);
648 :
649 6503884 : return NULL;
650 : }
651 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
652 :
653 27860224 : pgstat_count_index_tuples(scan->indexRelation, 1);
654 :
655 : /* Return the TID of the tuple we found. */
656 27860224 : return &scan->xs_heaptid;
657 : }
658 :
659 : /* ----------------
660 : * index_fetch_heap - get the scan's next heap tuple
661 : *
662 : * The result is a visible heap tuple associated with the index TID most
663 : * recently fetched by index_getnext_tid, or NULL if no more matching tuples
664 : * exist. (There can be more than one matching tuple because of HOT chains,
665 : * although when using an MVCC snapshot it should be impossible for more than
666 : * one such tuple to exist.)
667 : *
668 : * On success, the buffer containing the heap tup is pinned (the pin will be
669 : * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
670 : * call).
671 : *
672 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
673 : * scan keys if required. We do not do that here because we don't have
674 : * enough information to do it efficiently in the general case.
675 : * ----------------
676 : */
677 : bool
678 24404312 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
679 : {
680 24404312 : bool all_dead = false;
681 : bool found;
682 :
683 24404312 : found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
684 : scan->xs_snapshot, slot,
685 : &scan->xs_heap_continue, &all_dead);
686 :
687 24404302 : if (found)
688 23280748 : pgstat_count_heap_fetch(scan->indexRelation);
689 :
690 : /*
691 : * If we scanned a whole HOT chain and found only dead tuples, tell index
692 : * AM to kill its entry for that TID (this will take effect in the next
693 : * amgettuple call, in index_getnext_tid). We do not do this when in
694 : * recovery because it may violate MVCC to do so. See comments in
695 : * RelationGetIndexScan().
696 : */
697 24404302 : if (!scan->xactStartedInRecovery)
698 23917894 : scan->kill_prior_tuple = all_dead;
699 :
700 24404302 : return found;
701 : }
702 :
703 : /* ----------------
704 : * index_getnext_slot - get the next tuple from a scan
705 : *
706 : * The result is true if a tuple satisfying the scan keys and the snapshot was
707 : * found, false otherwise. The tuple is stored in the specified slot.
708 : *
709 : * On success, resources (like buffer pins) are likely to be held, and will be
710 : * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
711 : * call).
712 : *
713 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
714 : * scan keys if required. We do not do that here because we don't have
715 : * enough information to do it efficiently in the general case.
716 : * ----------------
717 : */
718 : bool
719 28516254 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
720 : {
721 : for (;;)
722 : {
723 28516254 : if (!scan->xs_heap_continue)
724 : {
725 : ItemPointer tid;
726 :
727 : /* Time to fetch the next TID from the index */
728 28358116 : tid = index_getnext_tid(scan, direction);
729 :
730 : /* If we're out of index entries, we're done */
731 28358116 : if (tid == NULL)
732 6300988 : break;
733 :
734 : Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
735 : }
736 :
737 : /*
738 : * Fetch the next (or only) visible heap tuple for this index entry.
739 : * If we don't find anything, loop around and grab the next TID from
740 : * the index.
741 : */
742 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
743 22215266 : if (index_fetch_heap(scan, slot))
744 21291016 : return true;
745 : }
746 :
747 6300988 : return false;
748 : }
749 :
750 : /* ----------------
751 : * index_getbitmap - get all tuples at once from an index scan
752 : *
753 : * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
754 : * Since there's no interlock between the index scan and the eventual heap
755 : * access, this is only safe to use with MVCC-based snapshots: the heap
756 : * item slot could have been replaced by a newer tuple by the time we get
757 : * to it.
758 : *
759 : * Returns the number of matching tuples found. (Note: this might be only
760 : * approximate, so it should only be used for statistical purposes.)
761 : * ----------------
762 : */
763 : int64
764 25794 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
765 : {
766 : int64 ntids;
767 :
768 : SCAN_CHECKS;
769 25794 : CHECK_SCAN_PROCEDURE(amgetbitmap);
770 :
771 : /* just make sure this is false... */
772 25794 : scan->kill_prior_tuple = false;
773 :
774 : /*
775 : * have the am's getbitmap proc do all the work.
776 : */
777 25794 : ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
778 :
779 25794 : pgstat_count_index_tuples(scan->indexRelation, ntids);
780 :
781 25794 : return ntids;
782 : }
783 :
784 : /* ----------------
785 : * index_bulk_delete - do mass deletion of index entries
786 : *
787 : * callback routine tells whether a given main-heap tuple is
788 : * to be deleted
789 : *
790 : * return value is an optional palloc'd struct of statistics
791 : * ----------------
792 : */
793 : IndexBulkDeleteResult *
794 2904 : index_bulk_delete(IndexVacuumInfo *info,
795 : IndexBulkDeleteResult *istat,
796 : IndexBulkDeleteCallback callback,
797 : void *callback_state)
798 : {
799 2904 : Relation indexRelation = info->index;
800 :
801 2904 : RELATION_CHECKS;
802 2904 : CHECK_REL_PROCEDURE(ambulkdelete);
803 :
804 2904 : return indexRelation->rd_indam->ambulkdelete(info, istat,
805 : callback, callback_state);
806 : }
807 :
808 : /* ----------------
809 : * index_vacuum_cleanup - do post-deletion cleanup of an index
810 : *
811 : * return value is an optional palloc'd struct of statistics
812 : * ----------------
813 : */
814 : IndexBulkDeleteResult *
815 163322 : index_vacuum_cleanup(IndexVacuumInfo *info,
816 : IndexBulkDeleteResult *istat)
817 : {
818 163322 : Relation indexRelation = info->index;
819 :
820 163322 : RELATION_CHECKS;
821 163322 : CHECK_REL_PROCEDURE(amvacuumcleanup);
822 :
823 163322 : return indexRelation->rd_indam->amvacuumcleanup(info, istat);
824 : }
825 :
826 : /* ----------------
827 : * index_can_return
828 : *
829 : * Does the index access method support index-only scans for the given
830 : * column?
831 : * ----------------
832 : */
833 : bool
834 1316826 : index_can_return(Relation indexRelation, int attno)
835 : {
836 1316826 : RELATION_CHECKS;
837 :
838 : /* amcanreturn is optional; assume false if not provided by AM */
839 1316826 : if (indexRelation->rd_indam->amcanreturn == NULL)
840 272948 : return false;
841 :
842 1043878 : return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
843 : }
844 :
845 : /* ----------------
846 : * index_getprocid
847 : *
848 : * Index access methods typically require support routines that are
849 : * not directly the implementation of any WHERE-clause query operator
850 : * and so cannot be kept in pg_amop. Instead, such routines are kept
851 : * in pg_amproc. These registered procedure OIDs are assigned numbers
852 : * according to a convention established by the access method.
853 : * The general index code doesn't know anything about the routines
854 : * involved; it just builds an ordered list of them for
855 : * each attribute on which an index is defined.
856 : *
857 : * As of Postgres 8.3, support routines within an operator family
858 : * are further subdivided by the "left type" and "right type" of the
859 : * query operator(s) that they support. The "default" functions for a
860 : * particular indexed attribute are those with both types equal to
861 : * the index opclass' opcintype (note that this is subtly different
862 : * from the indexed attribute's own type: it may be a binary-compatible
863 : * type instead). Only the default functions are stored in relcache
864 : * entries --- access methods can use the syscache to look up non-default
865 : * functions.
866 : *
867 : * This routine returns the requested default procedure OID for a
868 : * particular indexed attribute.
869 : * ----------------
870 : */
871 : RegProcedure
872 1898720 : index_getprocid(Relation irel,
873 : AttrNumber attnum,
874 : uint16 procnum)
875 : {
876 : RegProcedure *loc;
877 : int nproc;
878 : int procindex;
879 :
880 1898720 : nproc = irel->rd_indam->amsupport;
881 :
882 : Assert(procnum > 0 && procnum <= (uint16) nproc);
883 :
884 1898720 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
885 :
886 1898720 : loc = irel->rd_support;
887 :
888 : Assert(loc != NULL);
889 :
890 1898720 : return loc[procindex];
891 : }
892 :
893 : /* ----------------
894 : * index_getprocinfo
895 : *
896 : * This routine allows index AMs to keep fmgr lookup info for
897 : * support procs in the relcache. As above, only the "default"
898 : * functions for any particular indexed attribute are cached.
899 : *
900 : * Note: the return value points into cached data that will be lost during
901 : * any relcache rebuild! Therefore, either use the callinfo right away,
902 : * or save it only after having acquired some type of lock on the index rel.
903 : * ----------------
904 : */
905 : FmgrInfo *
906 45754700 : index_getprocinfo(Relation irel,
907 : AttrNumber attnum,
908 : uint16 procnum)
909 : {
910 : FmgrInfo *locinfo;
911 : int nproc;
912 : int optsproc;
913 : int procindex;
914 :
915 45754700 : nproc = irel->rd_indam->amsupport;
916 45754700 : optsproc = irel->rd_indam->amoptsprocnum;
917 :
918 : Assert(procnum > 0 && procnum <= (uint16) nproc);
919 :
920 45754700 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
921 :
922 45754700 : locinfo = irel->rd_supportinfo;
923 :
924 : Assert(locinfo != NULL);
925 :
926 45754700 : locinfo += procindex;
927 :
928 : /* Initialize the lookup info if first time through */
929 45754700 : if (locinfo->fn_oid == InvalidOid)
930 : {
931 1190222 : RegProcedure *loc = irel->rd_support;
932 : RegProcedure procId;
933 :
934 : Assert(loc != NULL);
935 :
936 1190222 : procId = loc[procindex];
937 :
938 : /*
939 : * Complain if function was not found during IndexSupportInitialize.
940 : * This should not happen unless the system tables contain bogus
941 : * entries for the index opclass. (If an AM wants to allow a support
942 : * function to be optional, it can use index_getprocid.)
943 : */
944 1190222 : if (!RegProcedureIsValid(procId))
945 0 : elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
946 : procnum, attnum, RelationGetRelationName(irel));
947 :
948 1190222 : fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
949 :
950 1190222 : if (procnum != optsproc)
951 : {
952 : /* Initialize locinfo->fn_expr with opclass options Const */
953 1188418 : bytea **attoptions = RelationGetIndexAttOptions(irel, false);
954 1188418 : MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
955 :
956 1188418 : set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
957 :
958 1188418 : MemoryContextSwitchTo(oldcxt);
959 : }
960 : }
961 :
962 45754700 : return locinfo;
963 : }
964 :
965 : /* ----------------
966 : * index_store_float8_orderby_distances
967 : *
968 : * Convert AM distance function's results (that can be inexact)
969 : * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
970 : * for a possible recheck.
971 : * ----------------
972 : */
973 : void
974 364600 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
975 : IndexOrderByDistance *distances,
976 : bool recheckOrderBy)
977 : {
978 : int i;
979 :
980 : Assert(distances || !recheckOrderBy);
981 :
982 364600 : scan->xs_recheckorderby = recheckOrderBy;
983 :
984 729218 : for (i = 0; i < scan->numberOfOrderBys; i++)
985 : {
986 364618 : if (orderByTypes[i] == FLOAT8OID)
987 : {
988 : #ifndef USE_FLOAT8_BYVAL
989 : /* must free any old value to avoid memory leakage */
990 : if (!scan->xs_orderbynulls[i])
991 : pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
992 : #endif
993 364488 : if (distances && !distances[i].isnull)
994 : {
995 364428 : scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
996 364428 : scan->xs_orderbynulls[i] = false;
997 : }
998 : else
999 : {
1000 60 : scan->xs_orderbyvals[i] = (Datum) 0;
1001 60 : scan->xs_orderbynulls[i] = true;
1002 : }
1003 : }
1004 130 : else if (orderByTypes[i] == FLOAT4OID)
1005 : {
1006 : /* convert distance function's result to ORDER BY type */
1007 70 : if (distances && !distances[i].isnull)
1008 : {
1009 70 : scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
1010 70 : scan->xs_orderbynulls[i] = false;
1011 : }
1012 : else
1013 : {
1014 0 : scan->xs_orderbyvals[i] = (Datum) 0;
1015 0 : scan->xs_orderbynulls[i] = true;
1016 : }
1017 : }
1018 : else
1019 : {
1020 : /*
1021 : * If the ordering operator's return value is anything else, we
1022 : * don't know how to convert the float8 bound calculated by the
1023 : * distance function to that. The executor won't actually need
1024 : * the order by values we return here, if there are no lossy
1025 : * results, so only insist on converting if the *recheck flag is
1026 : * set.
1027 : */
1028 60 : if (scan->xs_recheckorderby)
1029 0 : elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
1030 60 : scan->xs_orderbynulls[i] = true;
1031 : }
1032 : }
1033 364600 : }
1034 :
1035 : /* ----------------
1036 : * index_opclass_options
1037 : *
1038 : * Parse opclass-specific options for index column.
1039 : * ----------------
1040 : */
1041 : bytea *
1042 994120 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
1043 : bool validate)
1044 : {
1045 994120 : int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
1046 994120 : Oid procid = InvalidOid;
1047 : FmgrInfo *procinfo;
1048 : local_relopts relopts;
1049 :
1050 : /* fetch options support procedure if specified */
1051 994120 : if (amoptsprocnum != 0)
1052 994060 : procid = index_getprocid(indrel, attnum, amoptsprocnum);
1053 :
1054 994120 : if (!OidIsValid(procid))
1055 : {
1056 : Oid opclass;
1057 : Datum indclassDatum;
1058 : oidvector *indclass;
1059 :
1060 991582 : if (!DatumGetPointer(attoptions))
1061 991576 : return NULL; /* ok, no options, no procedure */
1062 :
1063 : /*
1064 : * Report an error if the opclass's options-parsing procedure does not
1065 : * exist but the opclass options are specified.
1066 : */
1067 6 : indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
1068 : Anum_pg_index_indclass);
1069 6 : indclass = (oidvector *) DatumGetPointer(indclassDatum);
1070 6 : opclass = indclass->values[attnum - 1];
1071 :
1072 6 : ereport(ERROR,
1073 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1074 : errmsg("operator class %s has no options",
1075 : generate_opclass_name(opclass))));
1076 : }
1077 :
1078 2538 : init_local_reloptions(&relopts, 0);
1079 :
1080 2538 : procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
1081 :
1082 2538 : (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
1083 :
1084 2538 : return build_local_reloptions(&relopts, attoptions, validate);
1085 : }
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