Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * nbtree.c
4 : * Implementation of Lehman and Yao's btree management algorithm for
5 : * Postgres.
6 : *
7 : * NOTES
8 : * This file contains only the public interface routines.
9 : *
10 : *
11 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
12 : * Portions Copyright (c) 1994, Regents of the University of California
13 : *
14 : * IDENTIFICATION
15 : * src/backend/access/nbtree/nbtree.c
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 : #include "postgres.h"
20 :
21 : #include "access/nbtree.h"
22 : #include "access/relscan.h"
23 : #include "access/stratnum.h"
24 : #include "commands/progress.h"
25 : #include "commands/vacuum.h"
26 : #include "nodes/execnodes.h"
27 : #include "pgstat.h"
28 : #include "storage/bulk_write.h"
29 : #include "storage/condition_variable.h"
30 : #include "storage/indexfsm.h"
31 : #include "storage/ipc.h"
32 : #include "storage/lmgr.h"
33 : #include "storage/read_stream.h"
34 : #include "utils/datum.h"
35 : #include "utils/fmgrprotos.h"
36 : #include "utils/index_selfuncs.h"
37 : #include "utils/memutils.h"
38 : #include "utils/wait_event.h"
39 :
40 :
41 : /*
42 : * BTPARALLEL_NOT_INITIALIZED indicates that the scan has not started.
43 : *
44 : * BTPARALLEL_NEED_PRIMSCAN indicates that some process must now seize the
45 : * scan to advance it via another call to _bt_first.
46 : *
47 : * BTPARALLEL_ADVANCING indicates that some process is advancing the scan to
48 : * a new page; others must wait.
49 : *
50 : * BTPARALLEL_IDLE indicates that no backend is currently advancing the scan
51 : * to a new page; some process can start doing that.
52 : *
53 : * BTPARALLEL_DONE indicates that the scan is complete (including error exit).
54 : */
55 : typedef enum
56 : {
57 : BTPARALLEL_NOT_INITIALIZED,
58 : BTPARALLEL_NEED_PRIMSCAN,
59 : BTPARALLEL_ADVANCING,
60 : BTPARALLEL_IDLE,
61 : BTPARALLEL_DONE,
62 : } BTPS_State;
63 :
64 : /*
65 : * BTParallelScanDescData contains btree specific shared information required
66 : * for parallel scan.
67 : */
68 : typedef struct BTParallelScanDescData
69 : {
70 : BlockNumber btps_nextScanPage; /* next page to be scanned */
71 : BlockNumber btps_lastCurrPage; /* page whose sibling link was copied into
72 : * btps_nextScanPage */
73 : BTPS_State btps_pageStatus; /* indicates whether next page is
74 : * available for scan. see above for
75 : * possible states of parallel scan. */
76 : LWLock btps_lock; /* protects shared parallel state */
77 : ConditionVariable btps_cv; /* used to synchronize parallel scan */
78 :
79 : /*
80 : * btps_arrElems is used when scans need to schedule another primitive
81 : * index scan with one or more SAOP arrays. Holds BTArrayKeyInfo.cur_elem
82 : * offsets for each = scan key associated with a ScalarArrayOp array.
83 : */
84 : int btps_arrElems[FLEXIBLE_ARRAY_MEMBER];
85 :
86 : /*
87 : * Additional space (at the end of the struct) is used when scans need to
88 : * schedule another primitive index scan with one or more skip arrays.
89 : * Holds a flattened datum representation for each = scan key associated
90 : * with a skip array.
91 : */
92 : } BTParallelScanDescData;
93 :
94 : typedef struct BTParallelScanDescData *BTParallelScanDesc;
95 :
96 :
97 : static bool _bt_start_prim_scan(IndexScanDesc scan);
98 : static void _bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
99 : BTScanOpaque so);
100 : static void _bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
101 : BTScanOpaque so);
102 : static void btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
103 : IndexBulkDeleteCallback callback, void *callback_state,
104 : BTCycleId cycleid);
105 : static BlockNumber btvacuumpage(BTVacState *vstate, Buffer buf);
106 : static BTVacuumPosting btreevacuumposting(BTVacState *vstate,
107 : IndexTuple posting,
108 : OffsetNumber updatedoffset,
109 : int *nremaining);
110 :
111 :
112 : /*
113 : * Btree handler function: return IndexAmRoutine with access method parameters
114 : * and callbacks.
115 : */
116 : Datum
117 2058703 : bthandler(PG_FUNCTION_ARGS)
118 : {
119 : static const IndexAmRoutine amroutine = {
120 : .type = T_IndexAmRoutine,
121 : .amstrategies = BTMaxStrategyNumber,
122 : .amsupport = BTNProcs,
123 : .amoptsprocnum = BTOPTIONS_PROC,
124 : .amcanorder = true,
125 : .amcanorderbyop = false,
126 : .amcanhash = false,
127 : .amconsistentequality = true,
128 : .amconsistentordering = true,
129 : .amcanbackward = true,
130 : .amcanunique = true,
131 : .amcanmulticol = true,
132 : .amoptionalkey = true,
133 : .amsearcharray = true,
134 : .amsearchnulls = true,
135 : .amstorage = false,
136 : .amclusterable = true,
137 : .ampredlocks = true,
138 : .amcanparallel = true,
139 : .amcanbuildparallel = true,
140 : .amcaninclude = true,
141 : .amusemaintenanceworkmem = false,
142 : .amsummarizing = false,
143 : .amparallelvacuumoptions =
144 : VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP,
145 : .amkeytype = InvalidOid,
146 :
147 : .ambuild = btbuild,
148 : .ambuildempty = btbuildempty,
149 : .aminsert = btinsert,
150 : .aminsertcleanup = NULL,
151 : .ambulkdelete = btbulkdelete,
152 : .amvacuumcleanup = btvacuumcleanup,
153 : .amcanreturn = btcanreturn,
154 : .amcostestimate = btcostestimate,
155 : .amgettreeheight = btgettreeheight,
156 : .amoptions = btoptions,
157 : .amproperty = btproperty,
158 : .ambuildphasename = btbuildphasename,
159 : .amvalidate = btvalidate,
160 : .amadjustmembers = btadjustmembers,
161 : .ambeginscan = btbeginscan,
162 : .amrescan = btrescan,
163 : .amgettuple = btgettuple,
164 : .amgetbitmap = btgetbitmap,
165 : .amendscan = btendscan,
166 : .ammarkpos = btmarkpos,
167 : .amrestrpos = btrestrpos,
168 : .amestimateparallelscan = btestimateparallelscan,
169 : .aminitparallelscan = btinitparallelscan,
170 : .amparallelrescan = btparallelrescan,
171 : .amtranslatestrategy = bttranslatestrategy,
172 : .amtranslatecmptype = bttranslatecmptype,
173 : };
174 :
175 2058703 : PG_RETURN_POINTER(&amroutine);
176 : }
177 :
178 : /*
179 : * btbuildempty() -- build an empty btree index in the initialization fork
180 : */
181 : void
182 111 : btbuildempty(Relation index)
183 : {
184 111 : bool allequalimage = _bt_allequalimage(index, false);
185 : BulkWriteState *bulkstate;
186 : BulkWriteBuffer metabuf;
187 :
188 111 : bulkstate = smgr_bulk_start_rel(index, INIT_FORKNUM);
189 :
190 : /* Construct metapage. */
191 111 : metabuf = smgr_bulk_get_buf(bulkstate);
192 111 : _bt_initmetapage((Page) metabuf, P_NONE, 0, allequalimage);
193 111 : smgr_bulk_write(bulkstate, BTREE_METAPAGE, metabuf, true);
194 :
195 111 : smgr_bulk_finish(bulkstate);
196 111 : }
197 :
198 : /*
199 : * btinsert() -- insert an index tuple into a btree.
200 : *
201 : * Descend the tree recursively, find the appropriate location for our
202 : * new tuple, and put it there.
203 : */
204 : bool
205 4613079 : btinsert(Relation rel, Datum *values, bool *isnull,
206 : ItemPointer ht_ctid, Relation heapRel,
207 : IndexUniqueCheck checkUnique,
208 : bool indexUnchanged,
209 : IndexInfo *indexInfo)
210 : {
211 : bool result;
212 : IndexTuple itup;
213 :
214 : /* generate an index tuple */
215 4613079 : itup = index_form_tuple(RelationGetDescr(rel), values, isnull);
216 4613079 : itup->t_tid = *ht_ctid;
217 :
218 4613079 : result = _bt_doinsert(rel, itup, checkUnique, indexUnchanged, heapRel);
219 :
220 4612753 : pfree(itup);
221 :
222 4612753 : return result;
223 : }
224 :
225 : /*
226 : * btgettuple() -- Get the next tuple in the scan.
227 : */
228 : bool
229 22487784 : btgettuple(IndexScanDesc scan, ScanDirection dir)
230 : {
231 22487784 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
232 : bool res;
233 :
234 : Assert(scan->heapRelation != NULL);
235 :
236 : /* btree indexes are never lossy */
237 22487784 : scan->xs_recheck = false;
238 :
239 : /* Each loop iteration performs another primitive index scan */
240 : do
241 : {
242 : /*
243 : * If we've already initialized this scan, we can just advance it in
244 : * the appropriate direction. If we haven't done so yet, we call
245 : * _bt_first() to get the first item in the scan.
246 : */
247 22499063 : if (!BTScanPosIsValid(so->currPos))
248 10199655 : res = _bt_first(scan, dir);
249 : else
250 : {
251 : /*
252 : * Check to see if we should kill the previously-fetched tuple.
253 : */
254 12299408 : if (scan->kill_prior_tuple)
255 : {
256 : /*
257 : * Yes, remember it for later. (We'll deal with all such
258 : * tuples at once right before leaving the index page.) The
259 : * test for numKilled overrun is not just paranoia: if the
260 : * caller reverses direction in the indexscan then the same
261 : * item might get entered multiple times. It's not worth
262 : * trying to optimize that, so we don't detect it, but instead
263 : * just forget any excess entries.
264 : */
265 269758 : if (so->killedItems == NULL)
266 101139 : so->killedItems = palloc_array(int, MaxTIDsPerBTreePage);
267 269758 : if (so->numKilled < MaxTIDsPerBTreePage)
268 269758 : so->killedItems[so->numKilled++] = so->currPos.itemIndex;
269 : }
270 :
271 : /*
272 : * Now continue the scan.
273 : */
274 12299408 : res = _bt_next(scan, dir);
275 : }
276 :
277 : /* If we have a tuple, return it ... */
278 22499063 : if (res)
279 18118152 : break;
280 : /* ... otherwise see if we need another primitive index scan */
281 4380911 : } while (so->numArrayKeys && _bt_start_prim_scan(scan));
282 :
283 22487784 : return res;
284 : }
285 :
286 : /*
287 : * btgetbitmap() -- gets all matching tuples, and adds them to a bitmap
288 : */
289 : int64
290 10946 : btgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
291 : {
292 10946 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
293 10946 : int64 ntids = 0;
294 : ItemPointer heapTid;
295 :
296 : Assert(scan->heapRelation == NULL);
297 :
298 : /* Each loop iteration performs another primitive index scan */
299 : do
300 : {
301 : /* Fetch the first page & tuple */
302 11454 : if (_bt_first(scan, ForwardScanDirection))
303 : {
304 : /* Save tuple ID, and continue scanning */
305 8857 : heapTid = &scan->xs_heaptid;
306 8857 : tbm_add_tuples(tbm, heapTid, 1, false);
307 8857 : ntids++;
308 :
309 : for (;;)
310 : {
311 : /*
312 : * Advance to next tuple within page. This is the same as the
313 : * easy case in _bt_next().
314 : */
315 1351559 : if (++so->currPos.itemIndex > so->currPos.lastItem)
316 : {
317 : /* let _bt_next do the heavy lifting */
318 12214 : if (!_bt_next(scan, ForwardScanDirection))
319 8857 : break;
320 : }
321 :
322 : /* Save tuple ID, and continue scanning */
323 1342702 : heapTid = &so->currPos.items[so->currPos.itemIndex].heapTid;
324 1342702 : tbm_add_tuples(tbm, heapTid, 1, false);
325 1342702 : ntids++;
326 : }
327 : }
328 : /* Now see if we need another primitive index scan */
329 11454 : } while (so->numArrayKeys && _bt_start_prim_scan(scan));
330 :
331 10946 : return ntids;
332 : }
333 :
334 : /*
335 : * btbeginscan() -- start a scan on a btree index
336 : */
337 : IndexScanDesc
338 9724242 : btbeginscan(Relation rel, int nkeys, int norderbys)
339 : {
340 : IndexScanDesc scan;
341 : BTScanOpaque so;
342 :
343 : /* no order by operators allowed */
344 : Assert(norderbys == 0);
345 :
346 : /* get the scan */
347 9724242 : scan = RelationGetIndexScan(rel, nkeys, norderbys);
348 :
349 : /* allocate private workspace */
350 9724242 : so = palloc_object(BTScanOpaqueData);
351 9724242 : BTScanPosInvalidate(so->currPos);
352 9724242 : BTScanPosInvalidate(so->markPos);
353 9724242 : if (scan->numberOfKeys > 0)
354 9716584 : so->keyData = (ScanKey) palloc(scan->numberOfKeys * sizeof(ScanKeyData));
355 : else
356 7658 : so->keyData = NULL;
357 :
358 9724242 : so->skipScan = false;
359 9724242 : so->needPrimScan = false;
360 9724242 : so->scanBehind = false;
361 9724242 : so->oppositeDirCheck = false;
362 9724242 : so->arrayKeys = NULL;
363 9724242 : so->orderProcs = NULL;
364 9724242 : so->arrayContext = NULL;
365 :
366 9724242 : so->killedItems = NULL; /* until needed */
367 9724242 : so->numKilled = 0;
368 :
369 : /*
370 : * We don't know yet whether the scan will be index-only, so we do not
371 : * allocate the tuple workspace arrays until btrescan. However, we set up
372 : * scan->xs_itupdesc whether we'll need it or not, since that's so cheap.
373 : */
374 9724242 : so->currTuples = so->markTuples = NULL;
375 :
376 9724242 : scan->xs_itupdesc = RelationGetDescr(rel);
377 :
378 9724242 : scan->opaque = so;
379 :
380 9724242 : return scan;
381 : }
382 :
383 : /*
384 : * btrescan() -- rescan an index relation
385 : */
386 : void
387 10200084 : btrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
388 : ScanKey orderbys, int norderbys)
389 : {
390 10200084 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
391 :
392 : /* we aren't holding any read locks, but gotta drop the pins */
393 10200084 : if (BTScanPosIsValid(so->currPos))
394 : {
395 : /* Before leaving current page, deal with any killed items */
396 102923 : if (so->numKilled > 0)
397 622 : _bt_killitems(scan);
398 102923 : BTScanPosUnpinIfPinned(so->currPos);
399 102923 : BTScanPosInvalidate(so->currPos);
400 : }
401 :
402 : /*
403 : * We prefer to eagerly drop leaf page pins before btgettuple returns.
404 : * This avoids making VACUUM wait to acquire a cleanup lock on the page.
405 : *
406 : * We cannot safely drop leaf page pins during index-only scans due to a
407 : * race condition involving VACUUM setting pages all-visible in the VM.
408 : * It's also unsafe for plain index scans that use a non-MVCC snapshot.
409 : *
410 : * Also opt out of dropping leaf page pins eagerly during bitmap scans.
411 : * Pins cannot be held for more than an instant during bitmap scans either
412 : * way, so we might as well avoid wasting cycles on acquiring page LSNs.
413 : *
414 : * See nbtree/README section on making concurrent TID recycling safe.
415 : *
416 : * Note: so->dropPin should never change across rescans.
417 : */
418 30362593 : so->dropPin = (!scan->xs_want_itup &&
419 19502760 : IsMVCCLikeSnapshot(scan->xs_snapshot) &&
420 9302676 : scan->heapRelation != NULL);
421 :
422 10200084 : so->markItemIndex = -1;
423 10200084 : so->needPrimScan = false;
424 10200084 : so->scanBehind = false;
425 10200084 : so->oppositeDirCheck = false;
426 10200084 : BTScanPosUnpinIfPinned(so->markPos);
427 10200084 : BTScanPosInvalidate(so->markPos);
428 :
429 : /*
430 : * Allocate tuple workspace arrays, if needed for an index-only scan and
431 : * not already done in a previous rescan call. To save on palloc
432 : * overhead, both workspaces are allocated as one palloc block; only this
433 : * function and btendscan know that.
434 : */
435 10200084 : if (scan->xs_want_itup && so->currTuples == NULL)
436 : {
437 87348 : so->currTuples = (char *) palloc(BLCKSZ * 2);
438 87348 : so->markTuples = so->currTuples + BLCKSZ;
439 : }
440 :
441 : /*
442 : * Reset the scan keys
443 : */
444 10200084 : if (scankey && scan->numberOfKeys > 0)
445 10192378 : memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
446 10200084 : so->numberOfKeys = 0; /* until _bt_preprocess_keys sets it */
447 10200084 : so->numArrayKeys = 0; /* ditto */
448 10200084 : }
449 :
450 : /*
451 : * btendscan() -- close down a scan
452 : */
453 : void
454 9723175 : btendscan(IndexScanDesc scan)
455 : {
456 9723175 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
457 :
458 : /* we aren't holding any read locks, but gotta drop the pins */
459 9723175 : if (BTScanPosIsValid(so->currPos))
460 : {
461 : /* Before leaving current page, deal with any killed items */
462 5715070 : if (so->numKilled > 0)
463 51512 : _bt_killitems(scan);
464 5715070 : BTScanPosUnpinIfPinned(so->currPos);
465 : }
466 :
467 9723175 : so->markItemIndex = -1;
468 9723175 : BTScanPosUnpinIfPinned(so->markPos);
469 :
470 : /* No need to invalidate positions, the RAM is about to be freed. */
471 :
472 : /* Release storage */
473 9723175 : if (so->keyData != NULL)
474 9715536 : pfree(so->keyData);
475 : /* so->arrayKeys and so->orderProcs are in arrayContext */
476 9723175 : if (so->arrayContext != NULL)
477 2920 : MemoryContextDelete(so->arrayContext);
478 9723175 : if (so->killedItems != NULL)
479 101098 : pfree(so->killedItems);
480 9723175 : if (so->currTuples != NULL)
481 87319 : pfree(so->currTuples);
482 : /* so->markTuples should not be pfree'd, see btrescan */
483 9723175 : pfree(so);
484 9723175 : }
485 :
486 : /*
487 : * btmarkpos() -- save current scan position
488 : */
489 : void
490 86058 : btmarkpos(IndexScanDesc scan)
491 : {
492 86058 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
493 :
494 : /* There may be an old mark with a pin (but no lock). */
495 86058 : BTScanPosUnpinIfPinned(so->markPos);
496 :
497 : /*
498 : * Just record the current itemIndex. If we later step to next page
499 : * before releasing the marked position, _bt_steppage makes a full copy of
500 : * the currPos struct in markPos. If (as often happens) the mark is moved
501 : * before we leave the page, we don't have to do that work.
502 : */
503 86058 : if (BTScanPosIsValid(so->currPos))
504 86058 : so->markItemIndex = so->currPos.itemIndex;
505 : else
506 : {
507 0 : BTScanPosInvalidate(so->markPos);
508 0 : so->markItemIndex = -1;
509 : }
510 86058 : }
511 :
512 : /*
513 : * btrestrpos() -- restore scan to last saved position
514 : */
515 : void
516 36012 : btrestrpos(IndexScanDesc scan)
517 : {
518 36012 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
519 :
520 36012 : if (so->markItemIndex >= 0)
521 : {
522 : /*
523 : * The scan has never moved to a new page since the last mark. Just
524 : * restore the itemIndex.
525 : *
526 : * NB: In this case we can't count on anything in so->markPos to be
527 : * accurate.
528 : */
529 35940 : so->currPos.itemIndex = so->markItemIndex;
530 : }
531 : else
532 : {
533 : /*
534 : * The scan moved to a new page after last mark or restore, and we are
535 : * now restoring to the marked page. We aren't holding any read
536 : * locks, but if we're still holding the pin for the current position,
537 : * we must drop it.
538 : */
539 72 : if (BTScanPosIsValid(so->currPos))
540 : {
541 : /* Before leaving current page, deal with any killed items */
542 72 : if (so->numKilled > 0)
543 0 : _bt_killitems(scan);
544 72 : BTScanPosUnpinIfPinned(so->currPos);
545 : }
546 :
547 72 : if (BTScanPosIsValid(so->markPos))
548 : {
549 : /* bump pin on mark buffer for assignment to current buffer */
550 72 : if (BTScanPosIsPinned(so->markPos))
551 0 : IncrBufferRefCount(so->markPos.buf);
552 72 : memcpy(&so->currPos, &so->markPos,
553 : offsetof(BTScanPosData, items[1]) +
554 72 : so->markPos.lastItem * sizeof(BTScanPosItem));
555 72 : if (so->currTuples)
556 0 : memcpy(so->currTuples, so->markTuples,
557 0 : so->markPos.nextTupleOffset);
558 : /* Reset the scan's array keys (see _bt_steppage for why) */
559 72 : if (so->numArrayKeys)
560 : {
561 0 : _bt_start_array_keys(scan, so->currPos.dir);
562 0 : so->needPrimScan = false;
563 : }
564 : }
565 : else
566 0 : BTScanPosInvalidate(so->currPos);
567 : }
568 36012 : }
569 :
570 : /*
571 : * btestimateparallelscan -- estimate storage for BTParallelScanDescData
572 : */
573 : Size
574 42 : btestimateparallelscan(Relation rel, int nkeys, int norderbys)
575 : {
576 42 : int16 nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
577 : Size estnbtreeshared,
578 : genericattrspace;
579 :
580 : /*
581 : * Pessimistically assume that every input scan key will be output with
582 : * its own SAOP array
583 : */
584 42 : estnbtreeshared = offsetof(BTParallelScanDescData, btps_arrElems) +
585 : sizeof(int) * nkeys;
586 :
587 : /* Single column indexes cannot possibly use a skip array */
588 42 : if (nkeyatts == 1)
589 30 : return estnbtreeshared;
590 :
591 : /*
592 : * Pessimistically assume that all attributes prior to the least
593 : * significant attribute require a skip array (and an associated key)
594 : */
595 12 : genericattrspace = datumEstimateSpace((Datum) 0, false, true,
596 : sizeof(Datum));
597 24 : for (int attnum = 1; attnum < nkeyatts; attnum++)
598 : {
599 : CompactAttribute *attr;
600 :
601 : /*
602 : * We make the conservative assumption that every index column will
603 : * also require a skip array.
604 : *
605 : * Every skip array must have space to store its scan key's sk_flags.
606 : */
607 12 : estnbtreeshared = add_size(estnbtreeshared, sizeof(int));
608 :
609 : /* Consider space required to store a datum of opclass input type */
610 12 : attr = TupleDescCompactAttr(rel->rd_att, attnum - 1);
611 12 : if (attr->attbyval)
612 12 : {
613 : /* This index attribute stores pass-by-value datums */
614 12 : Size estfixed = datumEstimateSpace((Datum) 0, false,
615 12 : true, attr->attlen);
616 :
617 12 : estnbtreeshared = add_size(estnbtreeshared, estfixed);
618 12 : continue;
619 : }
620 :
621 : /*
622 : * This index attribute stores pass-by-reference datums.
623 : *
624 : * Assume that serializing this array will use just as much space as a
625 : * pass-by-value datum, in addition to space for the largest possible
626 : * whole index tuple (this is not just a per-datum portion of the
627 : * largest possible tuple because that'd be almost as large anyway).
628 : *
629 : * This is quite conservative, but it's not clear how we could do much
630 : * better. The executor requires an up-front storage request size
631 : * that reliably covers the scan's high watermark memory usage. We
632 : * can't be sure of the real high watermark until the scan is over.
633 : */
634 0 : estnbtreeshared = add_size(estnbtreeshared, genericattrspace);
635 0 : estnbtreeshared = add_size(estnbtreeshared, BTMaxItemSize);
636 : }
637 :
638 12 : return estnbtreeshared;
639 : }
640 :
641 : /*
642 : * _bt_start_prim_scan() -- start scheduled primitive index scan?
643 : *
644 : * Returns true if _bt_checkkeys scheduled another primitive index scan, just
645 : * as the last one ended. Otherwise returns false, indicating that the array
646 : * keys are now fully exhausted.
647 : *
648 : * Only call here during scans with one or more equality type array scan keys,
649 : * after _bt_first or _bt_next return false.
650 : */
651 : static bool
652 58955 : _bt_start_prim_scan(IndexScanDesc scan)
653 : {
654 58955 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
655 :
656 : Assert(so->numArrayKeys);
657 :
658 58955 : so->scanBehind = so->oppositeDirCheck = false; /* reset */
659 :
660 : /*
661 : * Array keys are advanced within _bt_checkkeys when the scan reaches the
662 : * leaf level (more precisely, they're advanced when the scan reaches the
663 : * end of each distinct set of array elements). This process avoids
664 : * repeat access to leaf pages (across multiple primitive index scans) by
665 : * advancing the scan's array keys when it allows the primitive index scan
666 : * to find nearby matching tuples (or when it eliminates ranges of array
667 : * key space that can't possibly be satisfied by any index tuple).
668 : *
669 : * _bt_checkkeys sets a simple flag variable to schedule another primitive
670 : * index scan. The flag tells us what to do.
671 : *
672 : * We cannot rely on _bt_first always reaching _bt_checkkeys. There are
673 : * various cases where that won't happen. For example, if the index is
674 : * completely empty, then _bt_first won't call _bt_readpage/_bt_checkkeys.
675 : * We also don't expect a call to _bt_checkkeys during searches for a
676 : * non-existent value that happens to be lower/higher than any existing
677 : * value in the index.
678 : *
679 : * We don't require special handling for these cases -- we don't need to
680 : * be explicitly instructed to _not_ perform another primitive index scan.
681 : * It's up to code under the control of _bt_first to always set the flag
682 : * when another primitive index scan will be required.
683 : *
684 : * This works correctly, even with the tricky cases listed above, which
685 : * all involve access to leaf pages "near the boundaries of the key space"
686 : * (whether it's from a leftmost/rightmost page, or an imaginary empty
687 : * leaf root page). If _bt_checkkeys cannot be reached by a primitive
688 : * index scan for one set of array keys, then it also won't be reached for
689 : * any later set ("later" in terms of the direction that we scan the index
690 : * and advance the arrays). The array keys won't have advanced in these
691 : * cases, but that's the correct behavior (even _bt_advance_array_keys
692 : * won't always advance the arrays at the point they become "exhausted").
693 : */
694 58955 : if (so->needPrimScan)
695 : {
696 : /*
697 : * Flag was set -- must call _bt_first again, which will reset the
698 : * scan's needPrimScan flag
699 : */
700 11787 : return true;
701 : }
702 :
703 : /* The top-level index scan ran out of tuples in this scan direction */
704 47168 : if (scan->parallel_scan != NULL)
705 20 : _bt_parallel_done(scan);
706 :
707 47168 : return false;
708 : }
709 :
710 : /*
711 : * _bt_parallel_serialize_arrays() -- Serialize parallel array state.
712 : *
713 : * Caller must have exclusively locked btscan->btps_lock when called.
714 : */
715 : static void
716 24 : _bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
717 : BTScanOpaque so)
718 : {
719 : char *datumshared;
720 :
721 : /* Space for serialized datums begins immediately after btps_arrElems[] */
722 24 : datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
723 48 : for (int i = 0; i < so->numArrayKeys; i++)
724 : {
725 24 : BTArrayKeyInfo *array = &so->arrayKeys[i];
726 24 : ScanKey skey = &so->keyData[array->scan_key];
727 :
728 24 : if (array->num_elems != -1)
729 : {
730 : /* Save SAOP array's cur_elem (no need to copy key/datum) */
731 : Assert(!(skey->sk_flags & SK_BT_SKIP));
732 24 : btscan->btps_arrElems[i] = array->cur_elem;
733 24 : continue;
734 : }
735 :
736 : /* Save all mutable state associated with skip array's key */
737 : Assert(skey->sk_flags & SK_BT_SKIP);
738 0 : memcpy(datumshared, &skey->sk_flags, sizeof(int));
739 0 : datumshared += sizeof(int);
740 :
741 0 : if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
742 : {
743 : /* No sk_argument datum to serialize */
744 : Assert(skey->sk_argument == 0);
745 0 : continue;
746 : }
747 :
748 0 : datumSerialize(skey->sk_argument, (skey->sk_flags & SK_ISNULL) != 0,
749 0 : array->attbyval, array->attlen, &datumshared);
750 : }
751 24 : }
752 :
753 : /*
754 : * _bt_parallel_restore_arrays() -- Restore serialized parallel array state.
755 : *
756 : * Caller must have exclusively locked btscan->btps_lock when called.
757 : */
758 : static void
759 24 : _bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
760 : BTScanOpaque so)
761 : {
762 : char *datumshared;
763 :
764 : /* Space for serialized datums begins immediately after btps_arrElems[] */
765 24 : datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
766 48 : for (int i = 0; i < so->numArrayKeys; i++)
767 : {
768 24 : BTArrayKeyInfo *array = &so->arrayKeys[i];
769 24 : ScanKey skey = &so->keyData[array->scan_key];
770 : bool isnull;
771 :
772 24 : if (array->num_elems != -1)
773 : {
774 : /* Restore SAOP array using its saved cur_elem */
775 : Assert(!(skey->sk_flags & SK_BT_SKIP));
776 24 : array->cur_elem = btscan->btps_arrElems[i];
777 24 : skey->sk_argument = array->elem_values[array->cur_elem];
778 24 : continue;
779 : }
780 :
781 : /* Restore skip array by restoring its key directly */
782 0 : if (!array->attbyval && skey->sk_argument)
783 0 : pfree(DatumGetPointer(skey->sk_argument));
784 0 : skey->sk_argument = (Datum) 0;
785 0 : memcpy(&skey->sk_flags, datumshared, sizeof(int));
786 0 : datumshared += sizeof(int);
787 :
788 : Assert(skey->sk_flags & SK_BT_SKIP);
789 :
790 0 : if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
791 : {
792 : /* No sk_argument datum to restore */
793 0 : continue;
794 : }
795 :
796 0 : skey->sk_argument = datumRestore(&datumshared, &isnull);
797 0 : if (isnull)
798 : {
799 : Assert(skey->sk_argument == 0);
800 : Assert(skey->sk_flags & SK_SEARCHNULL);
801 : Assert(skey->sk_flags & SK_ISNULL);
802 : }
803 : }
804 24 : }
805 :
806 : /*
807 : * btinitparallelscan -- initialize BTParallelScanDesc for parallel btree scan
808 : */
809 : void
810 42 : btinitparallelscan(void *target)
811 : {
812 42 : BTParallelScanDesc bt_target = (BTParallelScanDesc) target;
813 :
814 42 : LWLockInitialize(&bt_target->btps_lock,
815 : LWTRANCHE_PARALLEL_BTREE_SCAN);
816 42 : bt_target->btps_nextScanPage = InvalidBlockNumber;
817 42 : bt_target->btps_lastCurrPage = InvalidBlockNumber;
818 42 : bt_target->btps_pageStatus = BTPARALLEL_NOT_INITIALIZED;
819 42 : ConditionVariableInit(&bt_target->btps_cv);
820 42 : }
821 :
822 : /*
823 : * btparallelrescan() -- reset parallel scan
824 : */
825 : void
826 16 : btparallelrescan(IndexScanDesc scan)
827 : {
828 : BTParallelScanDesc btscan;
829 16 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
830 :
831 : Assert(parallel_scan);
832 :
833 16 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
834 : parallel_scan->ps_offset_am);
835 :
836 : /*
837 : * In theory, we don't need to acquire the LWLock here, because there
838 : * shouldn't be any other workers running at this point, but we do so for
839 : * consistency.
840 : */
841 16 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
842 16 : btscan->btps_nextScanPage = InvalidBlockNumber;
843 16 : btscan->btps_lastCurrPage = InvalidBlockNumber;
844 16 : btscan->btps_pageStatus = BTPARALLEL_NOT_INITIALIZED;
845 16 : LWLockRelease(&btscan->btps_lock);
846 16 : }
847 :
848 : /*
849 : * _bt_parallel_seize() -- Begin the process of advancing the scan to a new
850 : * page. Other scans must wait until we call _bt_parallel_release()
851 : * or _bt_parallel_done().
852 : *
853 : * The return value is true if we successfully seized the scan and false
854 : * if we did not. The latter case occurs when no pages remain, or when
855 : * another primitive index scan is scheduled that caller's backend cannot
856 : * start just yet (only backends that call from _bt_first are capable of
857 : * starting primitive index scans, which they indicate by passing first=true).
858 : *
859 : * If the return value is true, *next_scan_page returns the next page of the
860 : * scan, and *last_curr_page returns the page that *next_scan_page came from.
861 : * An invalid *next_scan_page means the scan hasn't yet started, or that
862 : * caller needs to start the next primitive index scan (if it's the latter
863 : * case we'll set so.needPrimScan).
864 : *
865 : * Callers should ignore the value of *next_scan_page and *last_curr_page if
866 : * the return value is false.
867 : */
868 : bool
869 1104 : _bt_parallel_seize(IndexScanDesc scan, BlockNumber *next_scan_page,
870 : BlockNumber *last_curr_page, bool first)
871 : {
872 1104 : Relation rel = scan->indexRelation;
873 1104 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
874 1104 : bool exit_loop = false,
875 1104 : status = true,
876 1104 : endscan = false;
877 1104 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
878 : BTParallelScanDesc btscan;
879 :
880 1104 : *next_scan_page = InvalidBlockNumber;
881 1104 : *last_curr_page = InvalidBlockNumber;
882 :
883 : /*
884 : * Reset so->currPos, and initialize moreLeft/moreRight such that the next
885 : * call to _bt_readnextpage treats this backend similarly to a serial
886 : * backend that steps from *last_curr_page to *next_scan_page (unless this
887 : * backend's so->currPos is initialized by _bt_readfirstpage before then).
888 : */
889 1104 : BTScanPosInvalidate(so->currPos);
890 1104 : so->currPos.moreLeft = so->currPos.moreRight = true;
891 :
892 1104 : if (first)
893 : {
894 : /*
895 : * Initialize array related state when called from _bt_first, assuming
896 : * that this will be the first primitive index scan for the scan
897 : */
898 296 : so->needPrimScan = false;
899 296 : so->scanBehind = false;
900 296 : so->oppositeDirCheck = false;
901 : }
902 : else
903 : {
904 : /*
905 : * Don't attempt to seize the scan when it requires another primitive
906 : * index scan, since caller's backend cannot start it right now
907 : */
908 808 : if (so->needPrimScan)
909 0 : return false;
910 : }
911 :
912 1104 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
913 : parallel_scan->ps_offset_am);
914 :
915 : while (1)
916 : {
917 1104 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
918 :
919 1104 : if (btscan->btps_pageStatus == BTPARALLEL_DONE)
920 : {
921 : /* We're done with this parallel index scan */
922 208 : status = false;
923 : }
924 896 : else if (btscan->btps_pageStatus == BTPARALLEL_IDLE &&
925 814 : btscan->btps_nextScanPage == P_NONE)
926 : {
927 : /* End this parallel index scan */
928 6 : status = false;
929 6 : endscan = true;
930 : }
931 890 : else if (btscan->btps_pageStatus == BTPARALLEL_NEED_PRIMSCAN)
932 : {
933 : Assert(so->numArrayKeys);
934 :
935 24 : if (first)
936 : {
937 : /* Can start scheduled primitive scan right away, so do so */
938 24 : btscan->btps_pageStatus = BTPARALLEL_ADVANCING;
939 :
940 : /* Restore scan's array keys from serialized values */
941 24 : _bt_parallel_restore_arrays(rel, btscan, so);
942 24 : exit_loop = true;
943 : }
944 : else
945 : {
946 : /*
947 : * Don't attempt to seize the scan when it requires another
948 : * primitive index scan, since caller's backend cannot start
949 : * it right now
950 : */
951 0 : status = false;
952 : }
953 :
954 : /*
955 : * Either way, update backend local state to indicate that a
956 : * pending primitive scan is required
957 : */
958 24 : so->needPrimScan = true;
959 24 : so->scanBehind = false;
960 24 : so->oppositeDirCheck = false;
961 : }
962 866 : else if (btscan->btps_pageStatus != BTPARALLEL_ADVANCING)
963 : {
964 : /*
965 : * We have successfully seized control of the scan for the purpose
966 : * of advancing it to a new page!
967 : */
968 866 : btscan->btps_pageStatus = BTPARALLEL_ADVANCING;
969 : Assert(btscan->btps_nextScanPage != P_NONE);
970 866 : *next_scan_page = btscan->btps_nextScanPage;
971 866 : *last_curr_page = btscan->btps_lastCurrPage;
972 866 : exit_loop = true;
973 : }
974 1104 : LWLockRelease(&btscan->btps_lock);
975 1104 : if (exit_loop || !status)
976 : break;
977 0 : ConditionVariableSleep(&btscan->btps_cv, WAIT_EVENT_BTREE_PAGE);
978 : }
979 1104 : ConditionVariableCancelSleep();
980 :
981 : /* When the scan has reached the rightmost (or leftmost) page, end it */
982 1104 : if (endscan)
983 6 : _bt_parallel_done(scan);
984 :
985 1104 : return status;
986 : }
987 :
988 : /*
989 : * _bt_parallel_release() -- Complete the process of advancing the scan to a
990 : * new page. We now have the new value btps_nextScanPage; another backend
991 : * can now begin advancing the scan.
992 : *
993 : * Callers whose scan uses array keys must save their curr_page argument so
994 : * that it can be passed to _bt_parallel_primscan_schedule, should caller
995 : * determine that another primitive index scan is required.
996 : *
997 : * If caller's next_scan_page is P_NONE, the scan has reached the index's
998 : * rightmost/leftmost page. This is treated as reaching the end of the scan
999 : * within _bt_parallel_seize.
1000 : *
1001 : * Note: unlike the serial case, parallel scans don't need to remember both
1002 : * sibling links. next_scan_page is whichever link is next given the scan's
1003 : * direction. That's all we'll ever need, since the direction of a parallel
1004 : * scan can never change.
1005 : */
1006 : void
1007 890 : _bt_parallel_release(IndexScanDesc scan, BlockNumber next_scan_page,
1008 : BlockNumber curr_page)
1009 : {
1010 890 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
1011 : BTParallelScanDesc btscan;
1012 :
1013 : Assert(BlockNumberIsValid(next_scan_page));
1014 :
1015 890 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
1016 : parallel_scan->ps_offset_am);
1017 :
1018 890 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
1019 890 : btscan->btps_nextScanPage = next_scan_page;
1020 890 : btscan->btps_lastCurrPage = curr_page;
1021 890 : btscan->btps_pageStatus = BTPARALLEL_IDLE;
1022 890 : LWLockRelease(&btscan->btps_lock);
1023 890 : ConditionVariableSignal(&btscan->btps_cv);
1024 890 : }
1025 :
1026 : /*
1027 : * _bt_parallel_done() -- Mark the parallel scan as complete.
1028 : *
1029 : * When there are no pages left to scan, this function should be called to
1030 : * notify other workers. Otherwise, they might wait forever for the scan to
1031 : * advance to the next page.
1032 : */
1033 : void
1034 4392177 : _bt_parallel_done(IndexScanDesc scan)
1035 : {
1036 4392177 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1037 4392177 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
1038 : BTParallelScanDesc btscan;
1039 4392177 : bool status_changed = false;
1040 :
1041 : Assert(!BTScanPosIsValid(so->currPos));
1042 :
1043 : /* Do nothing, for non-parallel scans */
1044 4392177 : if (parallel_scan == NULL)
1045 4392073 : return;
1046 :
1047 : /*
1048 : * Should not mark parallel scan done when there's still a pending
1049 : * primitive index scan
1050 : */
1051 104 : if (so->needPrimScan)
1052 24 : return;
1053 :
1054 80 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
1055 : parallel_scan->ps_offset_am);
1056 :
1057 : /*
1058 : * Mark the parallel scan as done, unless some other process did so
1059 : * already
1060 : */
1061 80 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
1062 : Assert(btscan->btps_pageStatus != BTPARALLEL_NEED_PRIMSCAN);
1063 80 : if (btscan->btps_pageStatus != BTPARALLEL_DONE)
1064 : {
1065 58 : btscan->btps_pageStatus = BTPARALLEL_DONE;
1066 58 : status_changed = true;
1067 : }
1068 80 : LWLockRelease(&btscan->btps_lock);
1069 :
1070 : /* wake up all the workers associated with this parallel scan */
1071 80 : if (status_changed)
1072 58 : ConditionVariableBroadcast(&btscan->btps_cv);
1073 : }
1074 :
1075 : /*
1076 : * _bt_parallel_primscan_schedule() -- Schedule another primitive index scan.
1077 : *
1078 : * Caller passes the curr_page most recently passed to _bt_parallel_release
1079 : * by its backend. Caller successfully schedules the next primitive index scan
1080 : * if the shared parallel state hasn't been seized since caller's backend last
1081 : * advanced the scan.
1082 : */
1083 : void
1084 24 : _bt_parallel_primscan_schedule(IndexScanDesc scan, BlockNumber curr_page)
1085 : {
1086 24 : Relation rel = scan->indexRelation;
1087 24 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1088 24 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
1089 : BTParallelScanDesc btscan;
1090 :
1091 : Assert(so->numArrayKeys);
1092 :
1093 24 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
1094 : parallel_scan->ps_offset_am);
1095 :
1096 24 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
1097 24 : if (btscan->btps_lastCurrPage == curr_page &&
1098 24 : btscan->btps_pageStatus == BTPARALLEL_IDLE)
1099 : {
1100 24 : btscan->btps_nextScanPage = InvalidBlockNumber;
1101 24 : btscan->btps_lastCurrPage = InvalidBlockNumber;
1102 24 : btscan->btps_pageStatus = BTPARALLEL_NEED_PRIMSCAN;
1103 :
1104 : /* Serialize scan's current array keys */
1105 24 : _bt_parallel_serialize_arrays(rel, btscan, so);
1106 : }
1107 24 : LWLockRelease(&btscan->btps_lock);
1108 24 : }
1109 :
1110 : /*
1111 : * Bulk deletion of all index entries pointing to a set of heap tuples.
1112 : * The set of target tuples is specified via a callback routine that tells
1113 : * whether any given heap tuple (identified by ItemPointer) is being deleted.
1114 : *
1115 : * Result: a palloc'd struct containing statistical info for VACUUM displays.
1116 : */
1117 : IndexBulkDeleteResult *
1118 1795 : btbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
1119 : IndexBulkDeleteCallback callback, void *callback_state)
1120 : {
1121 1795 : Relation rel = info->index;
1122 : BTCycleId cycleid;
1123 :
1124 : /* allocate stats if first time through, else re-use existing struct */
1125 1795 : if (stats == NULL)
1126 1785 : stats = palloc0_object(IndexBulkDeleteResult);
1127 :
1128 : /* Establish the vacuum cycle ID to use for this scan */
1129 : /* The ENSURE stuff ensures we clean up shared memory on failure */
1130 1795 : PG_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
1131 : {
1132 1795 : cycleid = _bt_start_vacuum(rel);
1133 :
1134 1795 : btvacuumscan(info, stats, callback, callback_state, cycleid);
1135 : }
1136 1795 : PG_END_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
1137 1795 : _bt_end_vacuum(rel);
1138 :
1139 1795 : return stats;
1140 : }
1141 :
1142 : /*
1143 : * Post-VACUUM cleanup.
1144 : *
1145 : * Result: a palloc'd struct containing statistical info for VACUUM displays.
1146 : */
1147 : IndexBulkDeleteResult *
1148 152783 : btvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
1149 : {
1150 : BlockNumber num_delpages;
1151 :
1152 : /* No-op in ANALYZE ONLY mode */
1153 152783 : if (info->analyze_only)
1154 10050 : return stats;
1155 :
1156 : /*
1157 : * If btbulkdelete was called, we need not do anything (we just maintain
1158 : * the information used within _bt_vacuum_needs_cleanup() by calling
1159 : * _bt_set_cleanup_info() below).
1160 : *
1161 : * If btbulkdelete was _not_ called, then we have a choice to make: we
1162 : * must decide whether or not a btvacuumscan() call is needed now (i.e.
1163 : * whether the ongoing VACUUM operation can entirely avoid a physical scan
1164 : * of the index). A call to _bt_vacuum_needs_cleanup() decides it for us
1165 : * now.
1166 : */
1167 142733 : if (stats == NULL)
1168 : {
1169 : /* Check if VACUUM operation can entirely avoid btvacuumscan() call */
1170 141321 : if (!_bt_vacuum_needs_cleanup(info->index))
1171 141313 : return NULL;
1172 :
1173 : /*
1174 : * Since we aren't going to actually delete any leaf items, there's no
1175 : * need to go through all the vacuum-cycle-ID pushups here.
1176 : *
1177 : * Posting list tuples are a source of inaccuracy for cleanup-only
1178 : * scans. btvacuumscan() will assume that the number of index tuples
1179 : * from each page can be used as num_index_tuples, even though
1180 : * num_index_tuples is supposed to represent the number of TIDs in the
1181 : * index. This naive approach can underestimate the number of tuples
1182 : * in the index significantly.
1183 : *
1184 : * We handle the problem by making num_index_tuples an estimate in
1185 : * cleanup-only case.
1186 : */
1187 8 : stats = palloc0_object(IndexBulkDeleteResult);
1188 8 : btvacuumscan(info, stats, NULL, NULL, 0);
1189 8 : stats->estimated_count = true;
1190 : }
1191 :
1192 : /*
1193 : * Maintain num_delpages value in metapage for _bt_vacuum_needs_cleanup().
1194 : *
1195 : * num_delpages is the number of deleted pages now in the index that were
1196 : * not safe to place in the FSM to be recycled just yet. num_delpages is
1197 : * greater than 0 only when _bt_pagedel() actually deleted pages during
1198 : * our call to btvacuumscan(). Even then, _bt_pendingfsm_finalize() must
1199 : * have failed to place any newly deleted pages in the FSM just moments
1200 : * ago. (Actually, there are edge cases where recycling of the current
1201 : * VACUUM's newly deleted pages does not even become safe by the time the
1202 : * next VACUUM comes around. See nbtree/README.)
1203 : */
1204 : Assert(stats->pages_deleted >= stats->pages_free);
1205 1420 : num_delpages = stats->pages_deleted - stats->pages_free;
1206 1420 : _bt_set_cleanup_info(info->index, num_delpages);
1207 :
1208 : /*
1209 : * It's quite possible for us to be fooled by concurrent page splits into
1210 : * double-counting some index tuples, so disbelieve any total that exceeds
1211 : * the underlying heap's count ... if we know that accurately. Otherwise
1212 : * this might just make matters worse.
1213 : */
1214 1420 : if (!info->estimated_count)
1215 : {
1216 1385 : if (stats->num_index_tuples > info->num_heap_tuples)
1217 22 : stats->num_index_tuples = info->num_heap_tuples;
1218 : }
1219 :
1220 1420 : return stats;
1221 : }
1222 :
1223 : /*
1224 : * btvacuumscan --- scan the index for VACUUMing purposes
1225 : *
1226 : * This combines the functions of looking for leaf tuples that are deletable
1227 : * according to the vacuum callback, looking for empty pages that can be
1228 : * deleted, and looking for old deleted pages that can be recycled. Both
1229 : * btbulkdelete and btvacuumcleanup invoke this (the latter only if no
1230 : * btbulkdelete call occurred and _bt_vacuum_needs_cleanup returned true).
1231 : *
1232 : * The caller is responsible for initially allocating/zeroing a stats struct
1233 : * and for obtaining a vacuum cycle ID if necessary.
1234 : */
1235 : static void
1236 1803 : btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
1237 : IndexBulkDeleteCallback callback, void *callback_state,
1238 : BTCycleId cycleid)
1239 : {
1240 1803 : Relation rel = info->index;
1241 : BTVacState vstate;
1242 : BlockNumber num_pages;
1243 : bool needLock;
1244 : BlockRangeReadStreamPrivate p;
1245 1803 : ReadStream *stream = NULL;
1246 :
1247 : /*
1248 : * Reset fields that track information about the entire index now. This
1249 : * avoids double-counting in the case where a single VACUUM command
1250 : * requires multiple scans of the index.
1251 : *
1252 : * Avoid resetting the tuples_removed and pages_newly_deleted fields here,
1253 : * since they track information about the VACUUM command, and so must last
1254 : * across each call to btvacuumscan().
1255 : *
1256 : * (Note that pages_free is treated as state about the whole index, not
1257 : * the current VACUUM. This is appropriate because RecordFreeIndexPage()
1258 : * calls are idempotent, and get repeated for the same deleted pages in
1259 : * some scenarios. The point for us is to track the number of recyclable
1260 : * pages in the index at the end of the VACUUM command.)
1261 : */
1262 1803 : stats->num_pages = 0;
1263 1803 : stats->num_index_tuples = 0;
1264 1803 : stats->pages_deleted = 0;
1265 1803 : stats->pages_free = 0;
1266 :
1267 : /* Set up info to pass down to btvacuumpage */
1268 1803 : vstate.info = info;
1269 1803 : vstate.stats = stats;
1270 1803 : vstate.callback = callback;
1271 1803 : vstate.callback_state = callback_state;
1272 1803 : vstate.cycleid = cycleid;
1273 :
1274 : /* Create a temporary memory context to run _bt_pagedel in */
1275 1803 : vstate.pagedelcontext = AllocSetContextCreate(CurrentMemoryContext,
1276 : "_bt_pagedel",
1277 : ALLOCSET_DEFAULT_SIZES);
1278 :
1279 : /* Initialize vstate fields used by _bt_pendingfsm_finalize */
1280 1803 : vstate.bufsize = 0;
1281 1803 : vstate.maxbufsize = 0;
1282 1803 : vstate.pendingpages = NULL;
1283 1803 : vstate.npendingpages = 0;
1284 : /* Consider applying _bt_pendingfsm_finalize optimization */
1285 1803 : _bt_pendingfsm_init(rel, &vstate, (callback == NULL));
1286 :
1287 : /*
1288 : * The outer loop iterates over all index pages except the metapage, in
1289 : * physical order (we hope the kernel will cooperate in providing
1290 : * read-ahead for speed). It is critical that we visit all leaf pages,
1291 : * including ones added after we start the scan, else we might fail to
1292 : * delete some deletable tuples. Hence, we must repeatedly check the
1293 : * relation length. We must acquire the relation-extension lock while
1294 : * doing so to avoid a race condition: if someone else is extending the
1295 : * relation, there is a window where bufmgr/smgr have created a new
1296 : * all-zero page but it hasn't yet been write-locked by _bt_getbuf(). If
1297 : * we manage to scan such a page here, we'll improperly assume it can be
1298 : * recycled. Taking the lock synchronizes things enough to prevent a
1299 : * problem: either num_pages won't include the new page, or _bt_getbuf
1300 : * already has write lock on the buffer and it will be fully initialized
1301 : * before we can examine it. Also, we need not worry if a page is added
1302 : * immediately after we look; the page splitting code already has
1303 : * write-lock on the left page before it adds a right page, so we must
1304 : * already have processed any tuples due to be moved into such a page.
1305 : *
1306 : * XXX: Now that new pages are locked with RBM_ZERO_AND_LOCK, I don't
1307 : * think the use of the extension lock is still required.
1308 : *
1309 : * We can skip locking for new or temp relations, however, since no one
1310 : * else could be accessing them.
1311 : */
1312 1803 : needLock = !RELATION_IS_LOCAL(rel);
1313 :
1314 1803 : p.current_blocknum = BTREE_METAPAGE + 1;
1315 :
1316 : /*
1317 : * It is safe to use batchmode as block_range_read_stream_cb takes no
1318 : * locks.
1319 : */
1320 1803 : stream = read_stream_begin_relation(READ_STREAM_MAINTENANCE |
1321 : READ_STREAM_FULL |
1322 : READ_STREAM_USE_BATCHING,
1323 : info->strategy,
1324 : rel,
1325 : MAIN_FORKNUM,
1326 : block_range_read_stream_cb,
1327 : &p,
1328 : 0);
1329 : for (;;)
1330 : {
1331 : /* Get the current relation length */
1332 3426 : if (needLock)
1333 3424 : LockRelationForExtension(rel, ExclusiveLock);
1334 3426 : num_pages = RelationGetNumberOfBlocks(rel);
1335 3426 : if (needLock)
1336 3424 : UnlockRelationForExtension(rel, ExclusiveLock);
1337 :
1338 3426 : if (info->report_progress)
1339 565 : pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_TOTAL,
1340 : num_pages);
1341 :
1342 : /* Quit if we've scanned the whole relation */
1343 3426 : if (p.current_blocknum >= num_pages)
1344 1803 : break;
1345 :
1346 1623 : p.last_exclusive = num_pages;
1347 :
1348 : /* Iterate over pages, then loop back to recheck relation length */
1349 : while (true)
1350 16556 : {
1351 : BlockNumber current_block;
1352 : Buffer buf;
1353 :
1354 : /* call vacuum_delay_point while not holding any buffer lock */
1355 18179 : vacuum_delay_point(false);
1356 :
1357 18179 : buf = read_stream_next_buffer(stream, NULL);
1358 :
1359 18179 : if (!BufferIsValid(buf))
1360 1623 : break;
1361 :
1362 16556 : current_block = btvacuumpage(&vstate, buf);
1363 :
1364 16556 : if (info->report_progress)
1365 528 : pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
1366 : current_block);
1367 : }
1368 :
1369 : /*
1370 : * We have to reset the read stream to use it again. After returning
1371 : * InvalidBuffer, the read stream API won't invoke our callback again
1372 : * until the stream has been reset.
1373 : */
1374 1623 : read_stream_reset(stream);
1375 : }
1376 :
1377 1803 : read_stream_end(stream);
1378 :
1379 : /* Set statistics num_pages field to final size of index */
1380 1803 : stats->num_pages = num_pages;
1381 :
1382 1803 : MemoryContextDelete(vstate.pagedelcontext);
1383 :
1384 : /*
1385 : * If there were any calls to _bt_pagedel() during scan of the index then
1386 : * see if any of the resulting pages can be placed in the FSM now. When
1387 : * it's not safe we'll have to leave it up to a future VACUUM operation.
1388 : *
1389 : * Finally, if we placed any pages in the FSM (either just now or during
1390 : * the scan), forcibly update the upper-level FSM pages to ensure that
1391 : * searchers can find them.
1392 : */
1393 1803 : _bt_pendingfsm_finalize(rel, &vstate);
1394 1803 : if (stats->pages_free > 0)
1395 38 : IndexFreeSpaceMapVacuum(rel);
1396 1803 : }
1397 :
1398 : /*
1399 : * btvacuumpage --- VACUUM one page
1400 : *
1401 : * This processes a single page for btvacuumscan(). In some cases we must
1402 : * backtrack to re-examine and VACUUM pages that were on buf's page during
1403 : * a previous call here. This is how we handle page splits (that happened
1404 : * after our cycleid was acquired) whose right half page happened to reuse
1405 : * a block that we might have processed at some point before it was
1406 : * recycled (i.e. before the page split).
1407 : *
1408 : * Returns BlockNumber of a scanned page (not backtracked).
1409 : */
1410 : static BlockNumber
1411 16556 : btvacuumpage(BTVacState *vstate, Buffer buf)
1412 : {
1413 16556 : IndexVacuumInfo *info = vstate->info;
1414 16556 : IndexBulkDeleteResult *stats = vstate->stats;
1415 16556 : IndexBulkDeleteCallback callback = vstate->callback;
1416 16556 : void *callback_state = vstate->callback_state;
1417 16556 : Relation rel = info->index;
1418 16556 : Relation heaprel = info->heaprel;
1419 : bool attempt_pagedel;
1420 : BlockNumber blkno,
1421 : backtrack_to;
1422 16556 : BlockNumber scanblkno = BufferGetBlockNumber(buf);
1423 : Page page;
1424 : BTPageOpaque opaque;
1425 :
1426 16556 : blkno = scanblkno;
1427 :
1428 16556 : backtrack:
1429 :
1430 16556 : attempt_pagedel = false;
1431 16556 : backtrack_to = P_NONE;
1432 :
1433 16556 : _bt_lockbuf(rel, buf, BT_READ);
1434 16556 : page = BufferGetPage(buf);
1435 16556 : opaque = NULL;
1436 16556 : if (!PageIsNew(page))
1437 : {
1438 16556 : _bt_checkpage(rel, buf);
1439 16556 : opaque = BTPageGetOpaque(page);
1440 : }
1441 :
1442 : Assert(blkno <= scanblkno);
1443 16556 : if (blkno != scanblkno)
1444 : {
1445 : /*
1446 : * We're backtracking.
1447 : *
1448 : * We followed a right link to a sibling leaf page (a page that
1449 : * happens to be from a block located before scanblkno). The only
1450 : * case we want to do anything with is a live leaf page having the
1451 : * current vacuum cycle ID.
1452 : *
1453 : * The page had better be in a state that's consistent with what we
1454 : * expect. Check for conditions that imply corruption in passing. It
1455 : * can't be half-dead because only an interrupted VACUUM process can
1456 : * leave pages in that state, so we'd definitely have dealt with it
1457 : * back when the page was the scanblkno page (half-dead pages are
1458 : * always marked fully deleted by _bt_pagedel(), barring corruption).
1459 : */
1460 0 : if (!opaque || !P_ISLEAF(opaque) || P_ISHALFDEAD(opaque))
1461 : {
1462 : Assert(false);
1463 0 : ereport(LOG,
1464 : (errcode(ERRCODE_INDEX_CORRUPTED),
1465 : errmsg_internal("right sibling %u of scanblkno %u unexpectedly in an inconsistent state in index \"%s\"",
1466 : blkno, scanblkno, RelationGetRelationName(rel))));
1467 0 : _bt_relbuf(rel, buf);
1468 0 : return scanblkno;
1469 : }
1470 :
1471 : /*
1472 : * We may have already processed the page in an earlier call, when the
1473 : * page was scanblkno. This happens when the leaf page split occurred
1474 : * after the scan began, but before the right sibling page became the
1475 : * scanblkno.
1476 : *
1477 : * Page may also have been deleted by current btvacuumpage() call,
1478 : * since _bt_pagedel() sometimes deletes the right sibling page of
1479 : * scanblkno in passing (it does so after we decided where to
1480 : * backtrack to). We don't need to process this page as a deleted
1481 : * page a second time now (in fact, it would be wrong to count it as a
1482 : * deleted page in the bulk delete statistics a second time).
1483 : */
1484 0 : if (opaque->btpo_cycleid != vstate->cycleid || P_ISDELETED(opaque))
1485 : {
1486 : /* Done with current scanblkno (and all lower split pages) */
1487 0 : _bt_relbuf(rel, buf);
1488 0 : return scanblkno;
1489 : }
1490 : }
1491 :
1492 16556 : if (!opaque || BTPageIsRecyclable(page, heaprel))
1493 : {
1494 : /* Okay to recycle this page (which could be leaf or internal) */
1495 715 : RecordFreeIndexPage(rel, blkno);
1496 715 : stats->pages_deleted++;
1497 715 : stats->pages_free++;
1498 : }
1499 15841 : else if (P_ISDELETED(opaque))
1500 : {
1501 : /*
1502 : * Already deleted page (which could be leaf or internal). Can't
1503 : * recycle yet.
1504 : */
1505 153 : stats->pages_deleted++;
1506 : }
1507 15688 : else if (P_ISHALFDEAD(opaque))
1508 : {
1509 : /* Half-dead leaf page (from interrupted VACUUM) -- finish deleting */
1510 0 : attempt_pagedel = true;
1511 :
1512 : /*
1513 : * _bt_pagedel() will increment both pages_newly_deleted and
1514 : * pages_deleted stats in all cases (barring corruption)
1515 : */
1516 : }
1517 15688 : else if (P_ISLEAF(opaque))
1518 : {
1519 : OffsetNumber deletable[MaxIndexTuplesPerPage];
1520 : int ndeletable;
1521 : BTVacuumPosting updatable[MaxIndexTuplesPerPage];
1522 : int nupdatable;
1523 : OffsetNumber offnum,
1524 : minoff,
1525 : maxoff;
1526 : int nhtidsdead,
1527 : nhtidslive;
1528 :
1529 : /*
1530 : * Trade in the initial read lock for a full cleanup lock on this
1531 : * page. We must get such a lock on every leaf page over the course
1532 : * of the vacuum scan, whether or not it actually contains any
1533 : * deletable tuples --- see nbtree/README.
1534 : */
1535 14780 : _bt_upgradelockbufcleanup(rel, buf);
1536 :
1537 : /*
1538 : * Check whether we need to backtrack to earlier pages. What we are
1539 : * concerned about is a page split that happened since we started the
1540 : * vacuum scan. If the split moved tuples on the right half of the
1541 : * split (i.e. the tuples that sort high) to a block that we already
1542 : * passed over, then we might have missed the tuples. We need to
1543 : * backtrack now. (Must do this before possibly clearing btpo_cycleid
1544 : * or deleting scanblkno page below!)
1545 : */
1546 14780 : if (vstate->cycleid != 0 &&
1547 14696 : opaque->btpo_cycleid == vstate->cycleid &&
1548 2 : !(opaque->btpo_flags & BTP_SPLIT_END) &&
1549 2 : !P_RIGHTMOST(opaque) &&
1550 1 : opaque->btpo_next < scanblkno)
1551 0 : backtrack_to = opaque->btpo_next;
1552 :
1553 14780 : ndeletable = 0;
1554 14780 : nupdatable = 0;
1555 14780 : minoff = P_FIRSTDATAKEY(opaque);
1556 14780 : maxoff = PageGetMaxOffsetNumber(page);
1557 14780 : nhtidsdead = 0;
1558 14780 : nhtidslive = 0;
1559 14780 : if (callback)
1560 : {
1561 : /* btbulkdelete callback tells us what to delete (or update) */
1562 14696 : for (offnum = minoff;
1563 2849254 : offnum <= maxoff;
1564 2834558 : offnum = OffsetNumberNext(offnum))
1565 : {
1566 : IndexTuple itup;
1567 :
1568 2834558 : itup = (IndexTuple) PageGetItem(page,
1569 2834558 : PageGetItemId(page, offnum));
1570 :
1571 : Assert(!BTreeTupleIsPivot(itup));
1572 2834558 : if (!BTreeTupleIsPosting(itup))
1573 : {
1574 : /* Regular tuple, standard table TID representation */
1575 2736019 : if (callback(&itup->t_tid, callback_state))
1576 : {
1577 1114116 : deletable[ndeletable++] = offnum;
1578 1114116 : nhtidsdead++;
1579 : }
1580 : else
1581 1621903 : nhtidslive++;
1582 : }
1583 : else
1584 : {
1585 : BTVacuumPosting vacposting;
1586 : int nremaining;
1587 :
1588 : /* Posting list tuple */
1589 98539 : vacposting = btreevacuumposting(vstate, itup, offnum,
1590 : &nremaining);
1591 98539 : if (vacposting == NULL)
1592 : {
1593 : /*
1594 : * All table TIDs from the posting tuple remain, so no
1595 : * delete or update required
1596 : */
1597 : Assert(nremaining == BTreeTupleGetNPosting(itup));
1598 : }
1599 62851 : else if (nremaining > 0)
1600 : {
1601 :
1602 : /*
1603 : * Store metadata about posting list tuple in
1604 : * updatable array for entire page. Existing tuple
1605 : * will be updated during the later call to
1606 : * _bt_delitems_vacuum().
1607 : */
1608 : Assert(nremaining < BTreeTupleGetNPosting(itup));
1609 23824 : updatable[nupdatable++] = vacposting;
1610 23824 : nhtidsdead += BTreeTupleGetNPosting(itup) - nremaining;
1611 : }
1612 : else
1613 : {
1614 : /*
1615 : * All table TIDs from the posting list must be
1616 : * deleted. We'll delete the index tuple completely
1617 : * (no update required).
1618 : */
1619 : Assert(nremaining == 0);
1620 39027 : deletable[ndeletable++] = offnum;
1621 39027 : nhtidsdead += BTreeTupleGetNPosting(itup);
1622 39027 : pfree(vacposting);
1623 : }
1624 :
1625 98539 : nhtidslive += nremaining;
1626 : }
1627 : }
1628 : }
1629 :
1630 : /*
1631 : * Apply any needed deletes or updates. We issue just one
1632 : * _bt_delitems_vacuum() call per page, so as to minimize WAL traffic.
1633 : */
1634 14780 : if (ndeletable > 0 || nupdatable > 0)
1635 : {
1636 : Assert(nhtidsdead >= ndeletable + nupdatable);
1637 9226 : _bt_delitems_vacuum(rel, buf, deletable, ndeletable, updatable,
1638 : nupdatable);
1639 :
1640 9226 : stats->tuples_removed += nhtidsdead;
1641 : /* must recompute maxoff */
1642 9226 : maxoff = PageGetMaxOffsetNumber(page);
1643 :
1644 : /* can't leak memory here */
1645 33050 : for (int i = 0; i < nupdatable; i++)
1646 23824 : pfree(updatable[i]);
1647 : }
1648 : else
1649 : {
1650 : /*
1651 : * If the leaf page has been split during this vacuum cycle, it
1652 : * seems worth expending a write to clear btpo_cycleid even if we
1653 : * don't have any deletions to do. (If we do, _bt_delitems_vacuum
1654 : * takes care of this.) This ensures we won't process the page
1655 : * again.
1656 : *
1657 : * We treat this like a hint-bit update because there's no need to
1658 : * WAL-log it.
1659 : */
1660 : Assert(nhtidsdead == 0);
1661 5554 : if (vstate->cycleid != 0 &&
1662 5470 : opaque->btpo_cycleid == vstate->cycleid)
1663 : {
1664 0 : opaque->btpo_cycleid = 0;
1665 0 : MarkBufferDirtyHint(buf, true);
1666 : }
1667 : }
1668 :
1669 : /*
1670 : * If the leaf page is now empty, try to delete it; else count the
1671 : * live tuples (live table TIDs in posting lists are counted as
1672 : * separate live tuples). We don't delete when backtracking, though,
1673 : * since that would require teaching _bt_pagedel() about backtracking
1674 : * (doesn't seem worth adding more complexity to deal with that).
1675 : *
1676 : * We don't count the number of live TIDs during cleanup-only calls to
1677 : * btvacuumscan (i.e. when callback is not set). We count the number
1678 : * of index tuples directly instead. This avoids the expense of
1679 : * directly examining all of the tuples on each page. VACUUM will
1680 : * treat num_index_tuples as an estimate in cleanup-only case, so it
1681 : * doesn't matter that this underestimates num_index_tuples
1682 : * significantly in some cases.
1683 : */
1684 14780 : if (minoff > maxoff)
1685 3616 : attempt_pagedel = (blkno == scanblkno);
1686 11164 : else if (callback)
1687 11084 : stats->num_index_tuples += nhtidslive;
1688 : else
1689 80 : stats->num_index_tuples += maxoff - minoff + 1;
1690 :
1691 : Assert(!attempt_pagedel || nhtidslive == 0);
1692 : }
1693 :
1694 16556 : if (attempt_pagedel)
1695 : {
1696 : MemoryContext oldcontext;
1697 :
1698 : /* Run pagedel in a temp context to avoid memory leakage */
1699 3616 : MemoryContextReset(vstate->pagedelcontext);
1700 3616 : oldcontext = MemoryContextSwitchTo(vstate->pagedelcontext);
1701 :
1702 : /*
1703 : * _bt_pagedel maintains the bulk delete stats on our behalf;
1704 : * pages_newly_deleted and pages_deleted are likely to be incremented
1705 : * during call
1706 : */
1707 : Assert(blkno == scanblkno);
1708 3616 : _bt_pagedel(rel, buf, vstate);
1709 :
1710 3616 : MemoryContextSwitchTo(oldcontext);
1711 : /* pagedel released buffer, so we shouldn't */
1712 : }
1713 : else
1714 12940 : _bt_relbuf(rel, buf);
1715 :
1716 16556 : if (backtrack_to != P_NONE)
1717 : {
1718 0 : blkno = backtrack_to;
1719 :
1720 : /* check for vacuum delay while not holding any buffer lock */
1721 0 : vacuum_delay_point(false);
1722 :
1723 : /*
1724 : * We can't use _bt_getbuf() here because it always applies
1725 : * _bt_checkpage(), which will barf on an all-zero page. We want to
1726 : * recycle all-zero pages, not fail. Also, we want to use a
1727 : * nondefault buffer access strategy.
1728 : */
1729 0 : buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL,
1730 : info->strategy);
1731 0 : goto backtrack;
1732 : }
1733 :
1734 16556 : return scanblkno;
1735 : }
1736 :
1737 : /*
1738 : * btreevacuumposting --- determine TIDs still needed in posting list
1739 : *
1740 : * Returns metadata describing how to build replacement tuple without the TIDs
1741 : * that VACUUM needs to delete. Returned value is NULL in the common case
1742 : * where no changes are needed to caller's posting list tuple (we avoid
1743 : * allocating memory here as an optimization).
1744 : *
1745 : * The number of TIDs that should remain in the posting list tuple is set for
1746 : * caller in *nremaining.
1747 : */
1748 : static BTVacuumPosting
1749 98539 : btreevacuumposting(BTVacState *vstate, IndexTuple posting,
1750 : OffsetNumber updatedoffset, int *nremaining)
1751 : {
1752 98539 : int live = 0;
1753 98539 : int nitem = BTreeTupleGetNPosting(posting);
1754 98539 : ItemPointer items = BTreeTupleGetPosting(posting);
1755 98539 : BTVacuumPosting vacposting = NULL;
1756 :
1757 563247 : for (int i = 0; i < nitem; i++)
1758 : {
1759 464708 : if (!vstate->callback(items + i, vstate->callback_state))
1760 : {
1761 : /* Live table TID */
1762 234666 : live++;
1763 : }
1764 230042 : else if (vacposting == NULL)
1765 : {
1766 : /*
1767 : * First dead table TID encountered.
1768 : *
1769 : * It's now clear that we need to delete one or more dead table
1770 : * TIDs, so start maintaining metadata describing how to update
1771 : * existing posting list tuple.
1772 : */
1773 62851 : vacposting = palloc(offsetof(BTVacuumPostingData, deletetids) +
1774 : nitem * sizeof(uint16));
1775 :
1776 62851 : vacposting->itup = posting;
1777 62851 : vacposting->updatedoffset = updatedoffset;
1778 62851 : vacposting->ndeletedtids = 0;
1779 62851 : vacposting->deletetids[vacposting->ndeletedtids++] = i;
1780 : }
1781 : else
1782 : {
1783 : /* Second or subsequent dead table TID */
1784 167191 : vacposting->deletetids[vacposting->ndeletedtids++] = i;
1785 : }
1786 : }
1787 :
1788 98539 : *nremaining = live;
1789 98539 : return vacposting;
1790 : }
1791 :
1792 : /*
1793 : * btcanreturn() -- Check whether btree indexes support index-only scans.
1794 : *
1795 : * btrees always do, so this is trivial.
1796 : */
1797 : bool
1798 860200 : btcanreturn(Relation index, int attno)
1799 : {
1800 860200 : return true;
1801 : }
1802 :
1803 : /*
1804 : * btgettreeheight() -- Compute tree height for use by btcostestimate().
1805 : */
1806 : int
1807 561121 : btgettreeheight(Relation rel)
1808 : {
1809 561121 : return _bt_getrootheight(rel);
1810 : }
1811 :
1812 : CompareType
1813 0 : bttranslatestrategy(StrategyNumber strategy, Oid opfamily)
1814 : {
1815 0 : switch (strategy)
1816 : {
1817 0 : case BTLessStrategyNumber:
1818 0 : return COMPARE_LT;
1819 0 : case BTLessEqualStrategyNumber:
1820 0 : return COMPARE_LE;
1821 0 : case BTEqualStrategyNumber:
1822 0 : return COMPARE_EQ;
1823 0 : case BTGreaterEqualStrategyNumber:
1824 0 : return COMPARE_GE;
1825 0 : case BTGreaterStrategyNumber:
1826 0 : return COMPARE_GT;
1827 0 : default:
1828 0 : return COMPARE_INVALID;
1829 : }
1830 : }
1831 :
1832 : StrategyNumber
1833 0 : bttranslatecmptype(CompareType cmptype, Oid opfamily)
1834 : {
1835 0 : switch (cmptype)
1836 : {
1837 0 : case COMPARE_LT:
1838 0 : return BTLessStrategyNumber;
1839 0 : case COMPARE_LE:
1840 0 : return BTLessEqualStrategyNumber;
1841 0 : case COMPARE_EQ:
1842 0 : return BTEqualStrategyNumber;
1843 0 : case COMPARE_GE:
1844 0 : return BTGreaterEqualStrategyNumber;
1845 0 : case COMPARE_GT:
1846 0 : return BTGreaterStrategyNumber;
1847 0 : default:
1848 0 : return InvalidStrategy;
1849 : }
1850 : }
|
