Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indexam.c
4 : * general index access method routines
5 : *
6 : * Portions Copyright (c) 1996-2024, 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 16997320 : index_open(Oid relationId, LOCKMODE lockmode)
134 : {
135 : Relation r;
136 :
137 16997320 : r = relation_open(relationId, lockmode);
138 :
139 16997308 : validate_relation_kind(r);
140 :
141 16997286 : 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 17030144 : index_close(Relation relation, LOCKMODE lockmode)
178 : {
179 17030144 : LockRelId relid = relation->rd_lockInfo.lockRelId;
180 :
181 : Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
182 :
183 : /* The relcache does the real work... */
184 17030144 : RelationClose(relation);
185 :
186 17030144 : if (lockmode != NoLock)
187 15628252 : UnlockRelationId(&relid, lockmode);
188 17030144 : }
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 16999440 : validate_relation_kind(Relation r)
198 : {
199 16999440 : if (r->rd_rel->relkind != RELKIND_INDEX &&
200 10866 : 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 16999418 : }
206 :
207 :
208 : /* ----------------
209 : * index_insert - insert an index tuple into a relation
210 : * ----------------
211 : */
212 : bool
213 8142152 : 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 8142152 : RELATION_CHECKS;
223 8142152 : CHECK_REL_PROCEDURE(aminsert);
224 :
225 8142152 : if (!(indexRelation->rd_indam->ampredlocks))
226 576518 : CheckForSerializableConflictIn(indexRelation,
227 : (ItemPointer) NULL,
228 : InvalidBlockNumber);
229 :
230 8142152 : 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 3143790 : index_insert_cleanup(Relation indexRelation,
242 : IndexInfo *indexInfo)
243 : {
244 3143790 : RELATION_CHECKS;
245 :
246 3143790 : if (indexRelation->rd_indam->aminsertcleanup)
247 1096 : indexRelation->rd_indam->aminsertcleanup(indexRelation, indexInfo);
248 3143790 : }
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 12645048 : index_beginscan(Relation heapRelation,
257 : Relation indexRelation,
258 : Snapshot snapshot,
259 : int nkeys, int norderbys)
260 : {
261 : IndexScanDesc scan;
262 :
263 : Assert(snapshot != InvalidSnapshot);
264 :
265 12645048 : scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
266 :
267 : /*
268 : * Save additional parameters into the scandesc. Everything else was set
269 : * up by RelationGetIndexScan.
270 : */
271 12645048 : scan->heapRelation = heapRelation;
272 12645048 : scan->xs_snapshot = snapshot;
273 :
274 : /* prepare to fetch index matches from table */
275 12645048 : scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
276 :
277 12645048 : return scan;
278 : }
279 :
280 : /*
281 : * index_beginscan_bitmap - start a scan of an index with amgetbitmap
282 : *
283 : * As above, caller had better be holding some lock on the parent heap
284 : * relation, even though it's not explicitly mentioned here.
285 : */
286 : IndexScanDesc
287 17324 : index_beginscan_bitmap(Relation indexRelation,
288 : Snapshot snapshot,
289 : int nkeys)
290 : {
291 : IndexScanDesc scan;
292 :
293 : Assert(snapshot != InvalidSnapshot);
294 :
295 17324 : scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
296 :
297 : /*
298 : * Save additional parameters into the scandesc. Everything else was set
299 : * up by RelationGetIndexScan.
300 : */
301 17324 : scan->xs_snapshot = snapshot;
302 :
303 17324 : return scan;
304 : }
305 :
306 : /*
307 : * index_beginscan_internal --- common code for index_beginscan variants
308 : */
309 : static IndexScanDesc
310 12662750 : index_beginscan_internal(Relation indexRelation,
311 : int nkeys, int norderbys, Snapshot snapshot,
312 : ParallelIndexScanDesc pscan, bool temp_snap)
313 : {
314 : IndexScanDesc scan;
315 :
316 12662750 : RELATION_CHECKS;
317 12662750 : CHECK_REL_PROCEDURE(ambeginscan);
318 :
319 12662750 : if (!(indexRelation->rd_indam->ampredlocks))
320 4624 : PredicateLockRelation(indexRelation, snapshot);
321 :
322 : /*
323 : * We hold a reference count to the relcache entry throughout the scan.
324 : */
325 12662750 : RelationIncrementReferenceCount(indexRelation);
326 :
327 : /*
328 : * Tell the AM to open a scan.
329 : */
330 12662750 : scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
331 : norderbys);
332 : /* Initialize information for parallel scan. */
333 12662750 : scan->parallel_scan = pscan;
334 12662750 : scan->xs_temp_snap = temp_snap;
335 :
336 12662750 : return scan;
337 : }
338 :
339 : /* ----------------
340 : * index_rescan - (re)start a scan of an index
341 : *
342 : * During a restart, the caller may specify a new set of scankeys and/or
343 : * orderbykeys; but the number of keys cannot differ from what index_beginscan
344 : * was told. (Later we might relax that to "must not exceed", but currently
345 : * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
346 : * To restart the scan without changing keys, pass NULL for the key arrays.
347 : * (Of course, keys *must* be passed on the first call, unless
348 : * scan->numberOfKeys is zero.)
349 : * ----------------
350 : */
351 : void
352 13112632 : index_rescan(IndexScanDesc scan,
353 : ScanKey keys, int nkeys,
354 : ScanKey orderbys, int norderbys)
355 : {
356 : SCAN_CHECKS;
357 13112632 : CHECK_SCAN_PROCEDURE(amrescan);
358 :
359 : Assert(nkeys == scan->numberOfKeys);
360 : Assert(norderbys == scan->numberOfOrderBys);
361 :
362 : /* Release resources (like buffer pins) from table accesses */
363 13112632 : if (scan->xs_heapfetch)
364 13091886 : table_index_fetch_reset(scan->xs_heapfetch);
365 :
366 13112632 : scan->kill_prior_tuple = false; /* for safety */
367 13112632 : scan->xs_heap_continue = false;
368 :
369 13112632 : scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
370 : orderbys, norderbys);
371 13112632 : }
372 :
373 : /* ----------------
374 : * index_endscan - end a scan
375 : * ----------------
376 : */
377 : void
378 12661028 : index_endscan(IndexScanDesc scan)
379 : {
380 : SCAN_CHECKS;
381 12661028 : CHECK_SCAN_PROCEDURE(amendscan);
382 :
383 : /* Release resources (like buffer pins) from table accesses */
384 12661028 : if (scan->xs_heapfetch)
385 : {
386 12643818 : table_index_fetch_end(scan->xs_heapfetch);
387 12643818 : scan->xs_heapfetch = NULL;
388 : }
389 :
390 : /* End the AM's scan */
391 12661028 : scan->indexRelation->rd_indam->amendscan(scan);
392 :
393 : /* Release index refcount acquired by index_beginscan */
394 12661028 : RelationDecrementReferenceCount(scan->indexRelation);
395 :
396 12661028 : if (scan->xs_temp_snap)
397 378 : UnregisterSnapshot(scan->xs_snapshot);
398 :
399 : /* Release the scan data structure itself */
400 12661028 : IndexScanEnd(scan);
401 12661028 : }
402 :
403 : /* ----------------
404 : * index_markpos - mark a scan position
405 : * ----------------
406 : */
407 : void
408 130042 : index_markpos(IndexScanDesc scan)
409 : {
410 : SCAN_CHECKS;
411 130042 : CHECK_SCAN_PROCEDURE(ammarkpos);
412 :
413 130042 : scan->indexRelation->rd_indam->ammarkpos(scan);
414 130042 : }
415 :
416 : /* ----------------
417 : * index_restrpos - restore a scan position
418 : *
419 : * NOTE: this only restores the internal scan state of the index AM. See
420 : * comments for ExecRestrPos().
421 : *
422 : * NOTE: For heap, in the presence of HOT chains, mark/restore only works
423 : * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
424 : * most one returnable tuple in each HOT chain, and so restoring the prior
425 : * state at the granularity of the index AM is sufficient. Since the only
426 : * current user of mark/restore functionality is nodeMergejoin.c, this
427 : * effectively means that merge-join plans only work for MVCC snapshots. This
428 : * could be fixed if necessary, but for now it seems unimportant.
429 : * ----------------
430 : */
431 : void
432 54018 : index_restrpos(IndexScanDesc scan)
433 : {
434 : Assert(IsMVCCSnapshot(scan->xs_snapshot));
435 :
436 : SCAN_CHECKS;
437 54018 : CHECK_SCAN_PROCEDURE(amrestrpos);
438 :
439 : /* release resources (like buffer pins) from table accesses */
440 54018 : if (scan->xs_heapfetch)
441 54018 : table_index_fetch_reset(scan->xs_heapfetch);
442 :
443 54018 : scan->kill_prior_tuple = false; /* for safety */
444 54018 : scan->xs_heap_continue = false;
445 :
446 54018 : scan->indexRelation->rd_indam->amrestrpos(scan);
447 54018 : }
448 :
449 : /*
450 : * index_parallelscan_estimate - estimate shared memory for parallel scan
451 : */
452 : Size
453 58 : index_parallelscan_estimate(Relation indexRelation, int nkeys, int norderbys,
454 : Snapshot snapshot)
455 : {
456 : Size nbytes;
457 :
458 : Assert(snapshot != InvalidSnapshot);
459 :
460 58 : RELATION_CHECKS;
461 :
462 58 : nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
463 58 : nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
464 58 : nbytes = MAXALIGN(nbytes);
465 :
466 : /*
467 : * If amestimateparallelscan is not provided, assume there is no
468 : * AM-specific data needed. (It's hard to believe that could work, but
469 : * it's easy enough to cater to it here.)
470 : */
471 58 : if (indexRelation->rd_indam->amestimateparallelscan != NULL)
472 58 : nbytes = add_size(nbytes,
473 58 : indexRelation->rd_indam->amestimateparallelscan(nkeys,
474 : norderbys));
475 :
476 58 : return nbytes;
477 : }
478 :
479 : /*
480 : * index_parallelscan_initialize - initialize parallel scan
481 : *
482 : * We initialize both the ParallelIndexScanDesc proper and the AM-specific
483 : * information which follows it.
484 : *
485 : * This function calls access method specific initialization routine to
486 : * initialize am specific information. Call this just once in the leader
487 : * process; then, individual workers attach via index_beginscan_parallel.
488 : */
489 : void
490 58 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
491 : Snapshot snapshot, ParallelIndexScanDesc target)
492 : {
493 : Size offset;
494 :
495 : Assert(snapshot != InvalidSnapshot);
496 :
497 58 : RELATION_CHECKS;
498 :
499 58 : offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
500 : EstimateSnapshotSpace(snapshot));
501 58 : offset = MAXALIGN(offset);
502 :
503 58 : target->ps_locator = heapRelation->rd_locator;
504 58 : target->ps_indexlocator = indexRelation->rd_locator;
505 58 : target->ps_offset = offset;
506 58 : SerializeSnapshot(snapshot, target->ps_snapshot_data);
507 :
508 : /* aminitparallelscan is optional; assume no-op if not provided by AM */
509 58 : if (indexRelation->rd_indam->aminitparallelscan != NULL)
510 : {
511 : void *amtarget;
512 :
513 58 : amtarget = OffsetToPointer(target, offset);
514 58 : indexRelation->rd_indam->aminitparallelscan(amtarget);
515 : }
516 58 : }
517 :
518 : /* ----------------
519 : * index_parallelrescan - (re)start a parallel scan of an index
520 : * ----------------
521 : */
522 : void
523 24 : index_parallelrescan(IndexScanDesc scan)
524 : {
525 : SCAN_CHECKS;
526 :
527 24 : if (scan->xs_heapfetch)
528 24 : table_index_fetch_reset(scan->xs_heapfetch);
529 :
530 : /* amparallelrescan is optional; assume no-op if not provided by AM */
531 24 : if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
532 24 : scan->indexRelation->rd_indam->amparallelrescan(scan);
533 24 : }
534 :
535 : /*
536 : * index_beginscan_parallel - join parallel index scan
537 : *
538 : * Caller must be holding suitable locks on the heap and the index.
539 : */
540 : IndexScanDesc
541 378 : index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
542 : int norderbys, ParallelIndexScanDesc pscan)
543 : {
544 : Snapshot snapshot;
545 : IndexScanDesc scan;
546 :
547 : Assert(RelFileLocatorEquals(heaprel->rd_locator, pscan->ps_locator));
548 : Assert(RelFileLocatorEquals(indexrel->rd_locator, pscan->ps_indexlocator));
549 :
550 378 : snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
551 378 : RegisterSnapshot(snapshot);
552 378 : scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
553 : pscan, true);
554 :
555 : /*
556 : * Save additional parameters into the scandesc. Everything else was set
557 : * up by index_beginscan_internal.
558 : */
559 378 : scan->heapRelation = heaprel;
560 378 : scan->xs_snapshot = snapshot;
561 :
562 : /* prepare to fetch index matches from table */
563 378 : scan->xs_heapfetch = table_index_fetch_begin(heaprel);
564 :
565 378 : return scan;
566 : }
567 :
568 : /* ----------------
569 : * index_getnext_tid - get the next TID from a scan
570 : *
571 : * The result is the next TID satisfying the scan keys,
572 : * or NULL if no more matching tuples exist.
573 : * ----------------
574 : */
575 : ItemPointer
576 31746202 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
577 : {
578 : bool found;
579 :
580 : SCAN_CHECKS;
581 31746202 : CHECK_SCAN_PROCEDURE(amgettuple);
582 :
583 : /* XXX: we should assert that a snapshot is pushed or registered */
584 : Assert(TransactionIdIsValid(RecentXmin));
585 :
586 : /*
587 : * The AM's amgettuple proc finds the next index entry matching the scan
588 : * keys, and puts the TID into scan->xs_heaptid. It should also set
589 : * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
590 : * pay no attention to those fields here.
591 : */
592 31746202 : found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
593 :
594 : /* Reset kill flag immediately for safety */
595 31746202 : scan->kill_prior_tuple = false;
596 31746202 : scan->xs_heap_continue = false;
597 :
598 : /* If we're out of index entries, we're done */
599 31746202 : if (!found)
600 : {
601 : /* release resources (like buffer pins) from table accesses */
602 5963524 : if (scan->xs_heapfetch)
603 5963524 : table_index_fetch_reset(scan->xs_heapfetch);
604 :
605 5963524 : return NULL;
606 : }
607 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
608 :
609 25782678 : pgstat_count_index_tuples(scan->indexRelation, 1);
610 :
611 : /* Return the TID of the tuple we found. */
612 25782678 : return &scan->xs_heaptid;
613 : }
614 :
615 : /* ----------------
616 : * index_fetch_heap - get the scan's next heap tuple
617 : *
618 : * The result is a visible heap tuple associated with the index TID most
619 : * recently fetched by index_getnext_tid, or NULL if no more matching tuples
620 : * exist. (There can be more than one matching tuple because of HOT chains,
621 : * although when using an MVCC snapshot it should be impossible for more than
622 : * one such tuple to exist.)
623 : *
624 : * On success, the buffer containing the heap tup is pinned (the pin will be
625 : * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
626 : * call).
627 : *
628 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
629 : * scan keys if required. We do not do that here because we don't have
630 : * enough information to do it efficiently in the general case.
631 : * ----------------
632 : */
633 : bool
634 22500892 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
635 : {
636 22500892 : bool all_dead = false;
637 : bool found;
638 :
639 22500892 : found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
640 : scan->xs_snapshot, slot,
641 : &scan->xs_heap_continue, &all_dead);
642 :
643 22500882 : if (found)
644 21405750 : pgstat_count_heap_fetch(scan->indexRelation);
645 :
646 : /*
647 : * If we scanned a whole HOT chain and found only dead tuples, tell index
648 : * AM to kill its entry for that TID (this will take effect in the next
649 : * amgettuple call, in index_getnext_tid). We do not do this when in
650 : * recovery because it may violate MVCC to do so. See comments in
651 : * RelationGetIndexScan().
652 : */
653 22500882 : if (!scan->xactStartedInRecovery)
654 22043584 : scan->kill_prior_tuple = all_dead;
655 :
656 22500882 : return found;
657 : }
658 :
659 : /* ----------------
660 : * index_getnext_slot - get the next tuple from a scan
661 : *
662 : * The result is true if a tuple satisfying the scan keys and the snapshot was
663 : * found, false otherwise. The tuple is stored in the specified slot.
664 : *
665 : * On success, resources (like buffer pins) are likely to be held, and will be
666 : * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
667 : * call).
668 : *
669 : * Note: caller must check scan->xs_recheck, and perform rechecking of the
670 : * scan keys if required. We do not do that here because we don't have
671 : * enough information to do it efficiently in the general case.
672 : * ----------------
673 : */
674 : bool
675 26290520 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
676 : {
677 : for (;;)
678 : {
679 26290520 : if (!scan->xs_heap_continue)
680 : {
681 : ItemPointer tid;
682 :
683 : /* Time to fetch the next TID from the index */
684 26136634 : tid = index_getnext_tid(scan, direction);
685 :
686 : /* If we're out of index entries, we're done */
687 26136634 : if (tid == NULL)
688 5881074 : break;
689 :
690 : Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
691 : }
692 :
693 : /*
694 : * Fetch the next (or only) visible heap tuple for this index entry.
695 : * If we don't find anything, loop around and grab the next TID from
696 : * the index.
697 : */
698 : Assert(ItemPointerIsValid(&scan->xs_heaptid));
699 20409446 : if (index_fetch_heap(scan, slot))
700 19532006 : return true;
701 : }
702 :
703 5881074 : return false;
704 : }
705 :
706 : /* ----------------
707 : * index_getbitmap - get all tuples at once from an index scan
708 : *
709 : * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
710 : * Since there's no interlock between the index scan and the eventual heap
711 : * access, this is only safe to use with MVCC-based snapshots: the heap
712 : * item slot could have been replaced by a newer tuple by the time we get
713 : * to it.
714 : *
715 : * Returns the number of matching tuples found. (Note: this might be only
716 : * approximate, so it should only be used for statistical purposes.)
717 : * ----------------
718 : */
719 : int64
720 19670 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
721 : {
722 : int64 ntids;
723 :
724 : SCAN_CHECKS;
725 19670 : CHECK_SCAN_PROCEDURE(amgetbitmap);
726 :
727 : /* just make sure this is false... */
728 19670 : scan->kill_prior_tuple = false;
729 :
730 : /*
731 : * have the am's getbitmap proc do all the work.
732 : */
733 19670 : ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
734 :
735 19670 : pgstat_count_index_tuples(scan->indexRelation, ntids);
736 :
737 19670 : return ntids;
738 : }
739 :
740 : /* ----------------
741 : * index_bulk_delete - do mass deletion of index entries
742 : *
743 : * callback routine tells whether a given main-heap tuple is
744 : * to be deleted
745 : *
746 : * return value is an optional palloc'd struct of statistics
747 : * ----------------
748 : */
749 : IndexBulkDeleteResult *
750 2568 : index_bulk_delete(IndexVacuumInfo *info,
751 : IndexBulkDeleteResult *istat,
752 : IndexBulkDeleteCallback callback,
753 : void *callback_state)
754 : {
755 2568 : Relation indexRelation = info->index;
756 :
757 2568 : RELATION_CHECKS;
758 2568 : CHECK_REL_PROCEDURE(ambulkdelete);
759 :
760 2568 : return indexRelation->rd_indam->ambulkdelete(info, istat,
761 : callback, callback_state);
762 : }
763 :
764 : /* ----------------
765 : * index_vacuum_cleanup - do post-deletion cleanup of an index
766 : *
767 : * return value is an optional palloc'd struct of statistics
768 : * ----------------
769 : */
770 : IndexBulkDeleteResult *
771 137780 : index_vacuum_cleanup(IndexVacuumInfo *info,
772 : IndexBulkDeleteResult *istat)
773 : {
774 137780 : Relation indexRelation = info->index;
775 :
776 137780 : RELATION_CHECKS;
777 137780 : CHECK_REL_PROCEDURE(amvacuumcleanup);
778 :
779 137780 : return indexRelation->rd_indam->amvacuumcleanup(info, istat);
780 : }
781 :
782 : /* ----------------
783 : * index_can_return
784 : *
785 : * Does the index access method support index-only scans for the given
786 : * column?
787 : * ----------------
788 : */
789 : bool
790 1242318 : index_can_return(Relation indexRelation, int attno)
791 : {
792 1242318 : RELATION_CHECKS;
793 :
794 : /* amcanreturn is optional; assume false if not provided by AM */
795 1242318 : if (indexRelation->rd_indam->amcanreturn == NULL)
796 272818 : return false;
797 :
798 969500 : return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
799 : }
800 :
801 : /* ----------------
802 : * index_getprocid
803 : *
804 : * Index access methods typically require support routines that are
805 : * not directly the implementation of any WHERE-clause query operator
806 : * and so cannot be kept in pg_amop. Instead, such routines are kept
807 : * in pg_amproc. These registered procedure OIDs are assigned numbers
808 : * according to a convention established by the access method.
809 : * The general index code doesn't know anything about the routines
810 : * involved; it just builds an ordered list of them for
811 : * each attribute on which an index is defined.
812 : *
813 : * As of Postgres 8.3, support routines within an operator family
814 : * are further subdivided by the "left type" and "right type" of the
815 : * query operator(s) that they support. The "default" functions for a
816 : * particular indexed attribute are those with both types equal to
817 : * the index opclass' opcintype (note that this is subtly different
818 : * from the indexed attribute's own type: it may be a binary-compatible
819 : * type instead). Only the default functions are stored in relcache
820 : * entries --- access methods can use the syscache to look up non-default
821 : * functions.
822 : *
823 : * This routine returns the requested default procedure OID for a
824 : * particular indexed attribute.
825 : * ----------------
826 : */
827 : RegProcedure
828 1792754 : index_getprocid(Relation irel,
829 : AttrNumber attnum,
830 : uint16 procnum)
831 : {
832 : RegProcedure *loc;
833 : int nproc;
834 : int procindex;
835 :
836 1792754 : nproc = irel->rd_indam->amsupport;
837 :
838 : Assert(procnum > 0 && procnum <= (uint16) nproc);
839 :
840 1792754 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
841 :
842 1792754 : loc = irel->rd_support;
843 :
844 : Assert(loc != NULL);
845 :
846 1792754 : return loc[procindex];
847 : }
848 :
849 : /* ----------------
850 : * index_getprocinfo
851 : *
852 : * This routine allows index AMs to keep fmgr lookup info for
853 : * support procs in the relcache. As above, only the "default"
854 : * functions for any particular indexed attribute are cached.
855 : *
856 : * Note: the return value points into cached data that will be lost during
857 : * any relcache rebuild! Therefore, either use the callinfo right away,
858 : * or save it only after having acquired some type of lock on the index rel.
859 : * ----------------
860 : */
861 : FmgrInfo *
862 43161070 : index_getprocinfo(Relation irel,
863 : AttrNumber attnum,
864 : uint16 procnum)
865 : {
866 : FmgrInfo *locinfo;
867 : int nproc;
868 : int optsproc;
869 : int procindex;
870 :
871 43161070 : nproc = irel->rd_indam->amsupport;
872 43161070 : optsproc = irel->rd_indam->amoptsprocnum;
873 :
874 : Assert(procnum > 0 && procnum <= (uint16) nproc);
875 :
876 43161070 : procindex = (nproc * (attnum - 1)) + (procnum - 1);
877 :
878 43161070 : locinfo = irel->rd_supportinfo;
879 :
880 : Assert(locinfo != NULL);
881 :
882 43161070 : locinfo += procindex;
883 :
884 : /* Initialize the lookup info if first time through */
885 43161070 : if (locinfo->fn_oid == InvalidOid)
886 : {
887 1102736 : RegProcedure *loc = irel->rd_support;
888 : RegProcedure procId;
889 :
890 : Assert(loc != NULL);
891 :
892 1102736 : procId = loc[procindex];
893 :
894 : /*
895 : * Complain if function was not found during IndexSupportInitialize.
896 : * This should not happen unless the system tables contain bogus
897 : * entries for the index opclass. (If an AM wants to allow a support
898 : * function to be optional, it can use index_getprocid.)
899 : */
900 1102736 : if (!RegProcedureIsValid(procId))
901 0 : elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
902 : procnum, attnum, RelationGetRelationName(irel));
903 :
904 1102736 : fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
905 :
906 1102736 : if (procnum != optsproc)
907 : {
908 : /* Initialize locinfo->fn_expr with opclass options Const */
909 1101058 : bytea **attoptions = RelationGetIndexAttOptions(irel, false);
910 1101058 : MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
911 :
912 1101058 : set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
913 :
914 1101058 : MemoryContextSwitchTo(oldcxt);
915 : }
916 : }
917 :
918 43161070 : return locinfo;
919 : }
920 :
921 : /* ----------------
922 : * index_store_float8_orderby_distances
923 : *
924 : * Convert AM distance function's results (that can be inexact)
925 : * to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
926 : * for a possible recheck.
927 : * ----------------
928 : */
929 : void
930 364600 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
931 : IndexOrderByDistance *distances,
932 : bool recheckOrderBy)
933 : {
934 : int i;
935 :
936 : Assert(distances || !recheckOrderBy);
937 :
938 364600 : scan->xs_recheckorderby = recheckOrderBy;
939 :
940 729218 : for (i = 0; i < scan->numberOfOrderBys; i++)
941 : {
942 364618 : if (orderByTypes[i] == FLOAT8OID)
943 : {
944 : #ifndef USE_FLOAT8_BYVAL
945 : /* must free any old value to avoid memory leakage */
946 : if (!scan->xs_orderbynulls[i])
947 : pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
948 : #endif
949 364488 : if (distances && !distances[i].isnull)
950 : {
951 364428 : scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
952 364428 : scan->xs_orderbynulls[i] = false;
953 : }
954 : else
955 : {
956 60 : scan->xs_orderbyvals[i] = (Datum) 0;
957 60 : scan->xs_orderbynulls[i] = true;
958 : }
959 : }
960 130 : else if (orderByTypes[i] == FLOAT4OID)
961 : {
962 : /* convert distance function's result to ORDER BY type */
963 70 : if (distances && !distances[i].isnull)
964 : {
965 70 : scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
966 70 : scan->xs_orderbynulls[i] = false;
967 : }
968 : else
969 : {
970 0 : scan->xs_orderbyvals[i] = (Datum) 0;
971 0 : scan->xs_orderbynulls[i] = true;
972 : }
973 : }
974 : else
975 : {
976 : /*
977 : * If the ordering operator's return value is anything else, we
978 : * don't know how to convert the float8 bound calculated by the
979 : * distance function to that. The executor won't actually need
980 : * the order by values we return here, if there are no lossy
981 : * results, so only insist on converting if the *recheck flag is
982 : * set.
983 : */
984 60 : if (scan->xs_recheckorderby)
985 0 : elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
986 60 : scan->xs_orderbynulls[i] = true;
987 : }
988 : }
989 364600 : }
990 :
991 : /* ----------------
992 : * index_opclass_options
993 : *
994 : * Parse opclass-specific options for index column.
995 : * ----------------
996 : */
997 : bytea *
998 886474 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
999 : bool validate)
1000 : {
1001 886474 : int amoptsprocnum = indrel->rd_indam->amoptsprocnum;
1002 886474 : Oid procid = InvalidOid;
1003 : FmgrInfo *procinfo;
1004 : local_relopts relopts;
1005 :
1006 : /* fetch options support procedure if specified */
1007 886474 : if (amoptsprocnum != 0)
1008 886414 : procid = index_getprocid(indrel, attnum, amoptsprocnum);
1009 :
1010 886474 : if (!OidIsValid(procid))
1011 : {
1012 : Oid opclass;
1013 : Datum indclassDatum;
1014 : oidvector *indclass;
1015 :
1016 884062 : if (!DatumGetPointer(attoptions))
1017 884056 : return NULL; /* ok, no options, no procedure */
1018 :
1019 : /*
1020 : * Report an error if the opclass's options-parsing procedure does not
1021 : * exist but the opclass options are specified.
1022 : */
1023 6 : indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
1024 : Anum_pg_index_indclass);
1025 6 : indclass = (oidvector *) DatumGetPointer(indclassDatum);
1026 6 : opclass = indclass->values[attnum - 1];
1027 :
1028 6 : ereport(ERROR,
1029 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1030 : errmsg("operator class %s has no options",
1031 : generate_opclass_name(opclass))));
1032 : }
1033 :
1034 2412 : init_local_reloptions(&relopts, 0);
1035 :
1036 2412 : procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
1037 :
1038 2412 : (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
1039 :
1040 2412 : return build_local_reloptions(&relopts, attoptions, validate);
1041 : }
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