Age Owner Branch data TLA 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) 1996-2025, 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 : :
39 : :
40 : : /*
41 : : * BTPARALLEL_NOT_INITIALIZED indicates that the scan has not started.
42 : : *
43 : : * BTPARALLEL_NEED_PRIMSCAN indicates that some process must now seize the
44 : : * scan to advance it via another call to _bt_first.
45 : : *
46 : : * BTPARALLEL_ADVANCING indicates that some process is advancing the scan to
47 : : * a new page; others must wait.
48 : : *
49 : : * BTPARALLEL_IDLE indicates that no backend is currently advancing the scan
50 : : * to a new page; some process can start doing that.
51 : : *
52 : : * BTPARALLEL_DONE indicates that the scan is complete (including error exit).
53 : : */
54 : : typedef enum
55 : : {
56 : : BTPARALLEL_NOT_INITIALIZED,
57 : : BTPARALLEL_NEED_PRIMSCAN,
58 : : BTPARALLEL_ADVANCING,
59 : : BTPARALLEL_IDLE,
60 : : BTPARALLEL_DONE,
61 : : } BTPS_State;
62 : :
63 : : /*
64 : : * BTParallelScanDescData contains btree specific shared information required
65 : : * for parallel scan.
66 : : */
67 : : typedef struct BTParallelScanDescData
68 : : {
69 : : BlockNumber btps_nextScanPage; /* next page to be scanned */
70 : : BlockNumber btps_lastCurrPage; /* page whose sibling link was copied into
71 : : * btps_nextScanPage */
72 : : BTPS_State btps_pageStatus; /* indicates whether next page is
73 : : * available for scan. see above for
74 : : * possible states of parallel scan. */
75 : : LWLock btps_lock; /* protects shared parallel state */
76 : : ConditionVariable btps_cv; /* used to synchronize parallel scan */
77 : :
78 : : /*
79 : : * btps_arrElems is used when scans need to schedule another primitive
80 : : * index scan with one or more SAOP arrays. Holds BTArrayKeyInfo.cur_elem
81 : : * offsets for each = scan key associated with a ScalarArrayOp array.
82 : : */
83 : : int btps_arrElems[FLEXIBLE_ARRAY_MEMBER];
84 : :
85 : : /*
86 : : * Additional space (at the end of the struct) is used when scans need to
87 : : * schedule another primitive index scan with one or more skip arrays.
88 : : * Holds a flattened datum representation for each = scan key associated
89 : : * with a skip array.
90 : : */
91 : : } BTParallelScanDescData;
92 : :
93 : : typedef struct BTParallelScanDescData *BTParallelScanDesc;
94 : :
95 : :
96 : : static void _bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
97 : : BTScanOpaque so);
98 : : static void _bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
99 : : BTScanOpaque so);
100 : : static void btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
101 : : IndexBulkDeleteCallback callback, void *callback_state,
102 : : BTCycleId cycleid);
103 : : static BlockNumber btvacuumpage(BTVacState *vstate, Buffer buf);
104 : : static BTVacuumPosting btreevacuumposting(BTVacState *vstate,
105 : : IndexTuple posting,
106 : : OffsetNumber updatedoffset,
107 : : int *nremaining);
108 : :
109 : :
110 : : /*
111 : : * Btree handler function: return IndexAmRoutine with access method parameters
112 : : * and callbacks.
113 : : */
114 : : Datum
3520 tgl@sss.pgh.pa.us 115 :CBC 1394832 : bthandler(PG_FUNCTION_ARGS)
116 : : {
117 : 1394832 : IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
118 : :
3418 teodor@sigaev.ru 119 : 1394832 : amroutine->amstrategies = BTMaxStrategyNumber;
120 : 1394832 : amroutine->amsupport = BTNProcs;
1986 akorotkov@postgresql 121 : 1394832 : amroutine->amoptsprocnum = BTOPTIONS_PROC;
3520 tgl@sss.pgh.pa.us 122 : 1394832 : amroutine->amcanorder = true;
123 : 1394832 : amroutine->amcanorderbyop = false;
191 peter@eisentraut.org 124 : 1394832 : amroutine->amcanhash = false;
183 125 : 1394832 : amroutine->amconsistentequality = true;
126 : 1394832 : amroutine->amconsistentordering = true;
3520 tgl@sss.pgh.pa.us 127 : 1394832 : amroutine->amcanbackward = true;
128 : 1394832 : amroutine->amcanunique = true;
129 : 1394832 : amroutine->amcanmulticol = true;
130 : 1394832 : amroutine->amoptionalkey = true;
131 : 1394832 : amroutine->amsearcharray = true;
132 : 1394832 : amroutine->amsearchnulls = true;
133 : 1394832 : amroutine->amstorage = false;
134 : 1394832 : amroutine->amclusterable = true;
135 : 1394832 : amroutine->ampredlocks = true;
3125 rhaas@postgresql.org 136 : 1394832 : amroutine->amcanparallel = true;
638 tomas.vondra@postgre 137 : 1394832 : amroutine->amcanbuildparallel = true;
2709 teodor@sigaev.ru 138 : 1394832 : amroutine->amcaninclude = true;
2061 akapila@postgresql.o 139 : 1394832 : amroutine->amusemaintenanceworkmem = false;
901 tomas.vondra@postgre 140 : 1394832 : amroutine->amsummarizing = false;
2061 akapila@postgresql.o 141 : 1394832 : amroutine->amparallelvacuumoptions =
142 : : VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
3520 tgl@sss.pgh.pa.us 143 : 1394832 : amroutine->amkeytype = InvalidOid;
144 : :
145 : 1394832 : amroutine->ambuild = btbuild;
146 : 1394832 : amroutine->ambuildempty = btbuildempty;
147 : 1394832 : amroutine->aminsert = btinsert;
651 tomas.vondra@postgre 148 : 1394832 : amroutine->aminsertcleanup = NULL;
3520 tgl@sss.pgh.pa.us 149 : 1394832 : amroutine->ambulkdelete = btbulkdelete;
150 : 1394832 : amroutine->amvacuumcleanup = btvacuumcleanup;
151 : 1394832 : amroutine->amcanreturn = btcanreturn;
152 : 1394832 : amroutine->amcostestimate = btcostestimate;
361 peter@eisentraut.org 153 : 1394832 : amroutine->amgettreeheight = btgettreeheight;
3520 tgl@sss.pgh.pa.us 154 : 1394832 : amroutine->amoptions = btoptions;
3311 155 : 1394832 : amroutine->amproperty = btproperty;
2349 alvherre@alvh.no-ip. 156 : 1394832 : amroutine->ambuildphasename = btbuildphasename;
3520 tgl@sss.pgh.pa.us 157 : 1394832 : amroutine->amvalidate = btvalidate;
1862 158 : 1394832 : amroutine->amadjustmembers = btadjustmembers;
3520 159 : 1394832 : amroutine->ambeginscan = btbeginscan;
160 : 1394832 : amroutine->amrescan = btrescan;
161 : 1394832 : amroutine->amgettuple = btgettuple;
162 : 1394832 : amroutine->amgetbitmap = btgetbitmap;
163 : 1394832 : amroutine->amendscan = btendscan;
164 : 1394832 : amroutine->ammarkpos = btmarkpos;
165 : 1394832 : amroutine->amrestrpos = btrestrpos;
3125 rhaas@postgresql.org 166 : 1394832 : amroutine->amestimateparallelscan = btestimateparallelscan;
167 : 1394832 : amroutine->aminitparallelscan = btinitparallelscan;
168 : 1394832 : amroutine->amparallelrescan = btparallelrescan;
216 peter@eisentraut.org 169 : 1394832 : amroutine->amtranslatestrategy = bttranslatestrategy;
170 : 1394832 : amroutine->amtranslatecmptype = bttranslatecmptype;
171 : :
3520 tgl@sss.pgh.pa.us 172 : 1394832 : PG_RETURN_POINTER(amroutine);
173 : : }
174 : :
175 : : /*
176 : : * btbuildempty() -- build an empty btree index in the initialization fork
177 : : */
178 : : void
179 : 80 : btbuildempty(Relation index)
180 : : {
745 heikki.linnakangas@i 181 : 80 : bool allequalimage = _bt_allequalimage(index, false);
182 : : BulkWriteState *bulkstate;
183 : : BulkWriteBuffer metabuf;
184 : :
561 185 : 80 : bulkstate = smgr_bulk_start_rel(index, INIT_FORKNUM);
186 : :
187 : : /* Construct metapage. */
188 : 80 : metabuf = smgr_bulk_get_buf(bulkstate);
189 : 80 : _bt_initmetapage((Page) metabuf, P_NONE, 0, allequalimage);
190 : 80 : smgr_bulk_write(bulkstate, BTREE_METAPAGE, metabuf, true);
191 : :
192 : 80 : smgr_bulk_finish(bulkstate);
5365 rhaas@postgresql.org 193 : 80 : }
194 : :
195 : : /*
196 : : * btinsert() -- insert an index tuple into a btree.
197 : : *
198 : : * Descend the tree recursively, find the appropriate location for our
199 : : * new tuple, and put it there.
200 : : */
201 : : bool
3520 tgl@sss.pgh.pa.us 202 : 3648252 : btinsert(Relation rel, Datum *values, bool *isnull,
203 : : ItemPointer ht_ctid, Relation heapRel,
204 : : IndexUniqueCheck checkUnique,
205 : : bool indexUnchanged,
206 : : IndexInfo *indexInfo)
207 : : {
208 : : bool result;
209 : : IndexTuple itup;
210 : :
211 : : /* generate an index tuple */
7474 212 : 3648252 : itup = index_form_tuple(RelationGetDescr(rel), values, isnull);
10226 bruce@momjian.us 213 : 3648252 : itup->t_tid = *ht_ctid;
214 : :
1697 pg@bowt.ie 215 : 3648252 : result = _bt_doinsert(rel, itup, checkUnique, indexUnchanged, heapRel);
216 : :
10226 bruce@momjian.us 217 : 3647997 : pfree(itup);
218 : :
3520 tgl@sss.pgh.pa.us 219 : 3647997 : return result;
220 : : }
221 : :
222 : : /*
223 : : * btgettuple() -- Get the next tuple in the scan.
224 : : */
225 : : bool
226 : 16118200 : btgettuple(IndexScanDesc scan, ScanDirection dir)
227 : : {
8506 228 : 16118200 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
229 : : bool res;
230 : :
92 pg@bowt.ie 231 [ - + ]: 16118200 : Assert(scan->heapRelation != NULL);
232 : :
233 : : /* btree indexes are never lossy */
6355 tgl@sss.pgh.pa.us 234 : 16118200 : scan->xs_recheck = false;
235 : :
236 : : /* Each loop iteration performs another primitive index scan */
237 : : do
238 : : {
239 : : /*
240 : : * If we've already initialized this scan, we can just advance it in
241 : : * the appropriate direction. If we haven't done so yet, we call
242 : : * _bt_first() to get the first item in the scan.
243 : : */
5074 244 [ + + - + : 16126686 : if (!BTScanPosIsValid(so->currPos))
+ + ]
245 : 7001158 : res = _bt_first(scan, dir);
246 : : else
247 : : {
248 : : /*
249 : : * Check to see if we should kill the previously-fetched tuple.
250 : : */
251 [ + + ]: 9125528 : if (scan->kill_prior_tuple)
252 : : {
253 : : /*
254 : : * Yes, remember it for later. (We'll deal with all such
255 : : * tuples at once right before leaving the index page.) The
256 : : * test for numKilled overrun is not just paranoia: if the
257 : : * caller reverses direction in the indexscan then the same
258 : : * item might get entered multiple times. It's not worth
259 : : * trying to optimize that, so we don't detect it, but instead
260 : : * just forget any excess entries.
261 : : */
262 [ + + ]: 202126 : if (so->killedItems == NULL)
263 : 85799 : so->killedItems = (int *)
2019 pg@bowt.ie 264 : 85799 : palloc(MaxTIDsPerBTreePage * sizeof(int));
265 [ + - ]: 202126 : if (so->numKilled < MaxTIDsPerBTreePage)
5074 tgl@sss.pgh.pa.us 266 : 202126 : so->killedItems[so->numKilled++] = so->currPos.itemIndex;
267 : : }
268 : :
269 : : /*
270 : : * Now continue the scan.
271 : : */
272 : 9125528 : res = _bt_next(scan, dir);
273 : : }
274 : :
275 : : /* If we have a tuple, return it ... */
276 [ + + ]: 16126685 : if (res)
277 : 12741566 : break;
278 : : /* ... otherwise see if we need another primitive index scan */
518 pg@bowt.ie 279 [ + + + + ]: 3385119 : } while (so->numArrayKeys && _bt_start_prim_scan(scan, dir));
280 : :
3520 tgl@sss.pgh.pa.us 281 : 16118199 : return res;
282 : : }
283 : :
284 : : /*
285 : : * btgetbitmap() -- gets all matching tuples, and adds them to a bitmap
286 : : */
287 : : int64
288 : 6321 : btgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
289 : : {
7468 290 : 6321 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
6358 291 : 6321 : int64 ntids = 0;
292 : : ItemPointer heapTid;
293 : :
92 pg@bowt.ie 294 [ - + ]: 6321 : Assert(scan->heapRelation == NULL);
295 : :
296 : : /* Each loop iteration performs another primitive index scan */
297 : : do
298 : : {
299 : : /* Fetch the first page & tuple */
5074 tgl@sss.pgh.pa.us 300 [ + + ]: 6586 : if (_bt_first(scan, ForwardScanDirection))
301 : : {
302 : : /* Save tuple ID, and continue scanning */
2371 andres@anarazel.de 303 : 4901 : heapTid = &scan->xs_heaptid;
5074 tgl@sss.pgh.pa.us 304 : 4901 : tbm_add_tuples(tbm, heapTid, 1, false);
305 : 4901 : ntids++;
306 : :
307 : : for (;;)
308 : : {
309 : : /*
310 : : * Advance to next tuple within page. This is the same as the
311 : : * easy case in _bt_next().
312 : : */
313 [ + + ]: 941527 : if (++so->currPos.itemIndex > so->currPos.lastItem)
314 : : {
315 : : /* let _bt_next do the heavy lifting */
316 [ + + ]: 7432 : if (!_bt_next(scan, ForwardScanDirection))
317 : 4901 : break;
318 : : }
319 : :
320 : : /* Save tuple ID, and continue scanning */
321 : 936626 : heapTid = &so->currPos.items[so->currPos.itemIndex].heapTid;
322 : 936626 : tbm_add_tuples(tbm, heapTid, 1, false);
323 : 936626 : ntids++;
324 : : }
325 : : }
326 : : /* Now see if we need another primitive index scan */
518 pg@bowt.ie 327 [ + + + + ]: 6586 : } while (so->numArrayKeys && _bt_start_prim_scan(scan, ForwardScanDirection));
328 : :
3520 tgl@sss.pgh.pa.us 329 : 6321 : return ntids;
330 : : }
331 : :
332 : : /*
333 : : * btbeginscan() -- start a scan on a btree index
334 : : */
335 : : IndexScanDesc
336 : 6685097 : btbeginscan(Relation rel, int nkeys, int norderbys)
337 : : {
338 : : IndexScanDesc scan;
339 : : BTScanOpaque so;
340 : :
341 : : /* no order by operators allowed */
5392 342 [ - + ]: 6685097 : Assert(norderbys == 0);
343 : :
344 : : /* get the scan */
345 : 6685097 : scan = RelationGetIndexScan(rel, nkeys, norderbys);
346 : :
347 : : /* allocate private workspace */
348 : 6685097 : so = (BTScanOpaque) palloc(sizeof(BTScanOpaqueData));
3818 kgrittn@postgresql.o 349 : 6685097 : BTScanPosInvalidate(so->currPos);
350 : 6685097 : BTScanPosInvalidate(so->markPos);
5392 tgl@sss.pgh.pa.us 351 [ + + ]: 6685097 : if (scan->numberOfKeys > 0)
352 : 6678636 : so->keyData = (ScanKey) palloc(scan->numberOfKeys * sizeof(ScanKeyData));
353 : : else
354 : 6461 : so->keyData = NULL;
355 : :
155 pg@bowt.ie 356 : 6685097 : so->skipScan = false;
518 357 : 6685097 : so->needPrimScan = false;
358 : 6685097 : so->scanBehind = false;
325 359 : 6685097 : so->oppositeDirCheck = false;
5074 tgl@sss.pgh.pa.us 360 : 6685097 : so->arrayKeys = NULL;
518 pg@bowt.ie 361 : 6685097 : so->orderProcs = NULL;
5074 tgl@sss.pgh.pa.us 362 : 6685097 : so->arrayContext = NULL;
363 : :
5392 364 : 6685097 : so->killedItems = NULL; /* until needed */
365 : 6685097 : so->numKilled = 0;
366 : :
367 : : /*
368 : : * We don't know yet whether the scan will be index-only, so we do not
369 : : * allocate the tuple workspace arrays until btrescan. However, we set up
370 : : * scan->xs_itupdesc whether we'll need it or not, since that's so cheap.
371 : : */
5081 372 : 6685097 : so->currTuples = so->markTuples = NULL;
373 : :
5074 374 : 6685097 : scan->xs_itupdesc = RelationGetDescr(rel);
375 : :
5392 376 : 6685097 : scan->opaque = so;
377 : :
3520 378 : 6685097 : return scan;
379 : : }
380 : :
381 : : /*
382 : : * btrescan() -- rescan an index relation
383 : : */
384 : : void
385 : 6999708 : btrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
386 : : ScanKey orderbys, int norderbys)
387 : : {
5392 388 : 6999708 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
389 : :
390 : : /* we aren't holding any read locks, but gotta drop the pins */
7062 391 [ + + - + : 6999708 : if (BTScanPosIsValid(so->currPos))
+ + ]
392 : : {
393 : : /* Before leaving current page, deal with any killed items */
394 [ + + ]: 40408 : if (so->numKilled > 0)
3818 kgrittn@postgresql.o 395 : 484 : _bt_killitems(scan);
396 [ - + - - : 40408 : BTScanPosUnpinIfPinned(so->currPos);
+ + ]
397 : 40408 : BTScanPosInvalidate(so->currPos);
398 : : }
399 : :
400 : : /*
401 : : * We prefer to eagerly drop leaf page pins before btgettuple returns.
402 : : * This avoids making VACUUM wait to acquire a cleanup lock on the page.
403 : : *
404 : : * We cannot safely drop leaf page pins during index-only scans due to a
405 : : * race condition involving VACUUM setting pages all-visible in the VM.
406 : : * It's also unsafe for plain index scans that use a non-MVCC snapshot.
407 : : *
408 : : * When we drop pins eagerly, the mechanism that marks so->killedItems[]
409 : : * index tuples LP_DEAD has to deal with concurrent TID recycling races.
410 : : * The scheme used to detect unsafe TID recycling won't work when scanning
411 : : * unlogged relations (since it involves saving an affected page's LSN).
412 : : * Opt out of eager pin dropping during unlogged relation scans for now
413 : : * (this is preferable to opting out of kill_prior_tuple LP_DEAD setting).
414 : : *
415 : : * Also opt out of dropping leaf page pins eagerly during bitmap scans.
416 : : * Pins cannot be held for more than an instant during bitmap scans either
417 : : * way, so we might as well avoid wasting cycles on acquiring page LSNs.
418 : : *
419 : : * See nbtree/README section on making concurrent TID recycling safe.
420 : : *
421 : : * Note: so->dropPin should never change across rescans.
422 : : */
92 pg@bowt.ie 423 : 20822654 : so->dropPin = (!scan->xs_want_itup &&
424 [ + + + + ]: 6823238 : IsMVCCSnapshot(scan->xs_snapshot) &&
425 [ + + + + : 20025372 : RelationNeedsWAL(scan->indexRelation) &&
+ + + + +
+ ]
426 [ + + ]: 6202426 : scan->heapRelation != NULL);
427 : :
6953 tgl@sss.pgh.pa.us 428 : 6999708 : so->markItemIndex = -1;
518 pg@bowt.ie 429 : 6999708 : so->needPrimScan = false;
430 : 6999708 : so->scanBehind = false;
325 431 : 6999708 : so->oppositeDirCheck = false;
3818 kgrittn@postgresql.o 432 [ + - - + : 6999708 : BTScanPosUnpinIfPinned(so->markPos);
- + ]
433 : 6999708 : BTScanPosInvalidate(so->markPos);
434 : :
435 : : /*
436 : : * Allocate tuple workspace arrays, if needed for an index-only scan and
437 : : * not already done in a previous rescan call. To save on palloc
438 : : * overhead, both workspaces are allocated as one palloc block; only this
439 : : * function and btendscan know that.
440 : : *
441 : : * NOTE: this data structure also makes it safe to return data from a
442 : : * "name" column, even though btree name_ops uses an underlying storage
443 : : * datatype of cstring. The risk there is that "name" is supposed to be
444 : : * padded to NAMEDATALEN, but the actual index tuple is probably shorter.
445 : : * However, since we only return data out of tuples sitting in the
446 : : * currTuples array, a fetch of NAMEDATALEN bytes can at worst pull some
447 : : * data out of the markTuples array --- running off the end of memory for
448 : : * a SIGSEGV is not possible. Yeah, this is ugly as sin, but it beats
449 : : * adding special-case treatment for name_ops elsewhere.
450 : : */
5081 tgl@sss.pgh.pa.us 451 [ + + + + ]: 6999708 : if (scan->xs_want_itup && so->currTuples == NULL)
452 : : {
453 : 66814 : so->currTuples = (char *) palloc(BLCKSZ * 2);
454 : 66814 : so->markTuples = so->currTuples + BLCKSZ;
455 : : }
456 : :
457 : : /*
458 : : * Reset the scan keys
459 : : */
8203 460 [ + + + + ]: 6999708 : if (scankey && scan->numberOfKeys > 0)
360 peter@eisentraut.org 461 : 6993136 : memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
7969 tgl@sss.pgh.pa.us 462 : 6999708 : so->numberOfKeys = 0; /* until _bt_preprocess_keys sets it */
518 pg@bowt.ie 463 : 6999708 : so->numArrayKeys = 0; /* ditto */
10651 scrappy@hub.org 464 : 6999708 : }
465 : :
466 : : /*
467 : : * btendscan() -- close down a scan
468 : : */
469 : : void
3520 tgl@sss.pgh.pa.us 470 : 6684294 : btendscan(IndexScanDesc scan)
471 : : {
7062 472 : 6684294 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
473 : :
474 : : /* we aren't holding any read locks, but gotta drop the pins */
475 [ + + - + : 6684294 : if (BTScanPosIsValid(so->currPos))
+ + ]
476 : : {
477 : : /* Before leaving current page, deal with any killed items */
478 [ + + ]: 3575055 : if (so->numKilled > 0)
3818 kgrittn@postgresql.o 479 : 45334 : _bt_killitems(scan);
480 [ - + - - : 3575055 : BTScanPosUnpinIfPinned(so->currPos);
+ + ]
481 : : }
482 : :
6953 tgl@sss.pgh.pa.us 483 : 6684294 : so->markItemIndex = -1;
3818 kgrittn@postgresql.o 484 [ + + - + : 6684294 : BTScanPosUnpinIfPinned(so->markPos);
+ + ]
485 : :
486 : : /* No need to invalidate positions, the RAM is about to be freed. */
487 : :
488 : : /* Release storage */
7913 neilc@samurai.com 489 [ + + ]: 6684294 : if (so->keyData != NULL)
10226 bruce@momjian.us 490 : 6677848 : pfree(so->keyData);
491 : : /* so->arrayKeys and so->orderProcs are in arrayContext */
5074 tgl@sss.pgh.pa.us 492 [ + + ]: 6684294 : if (so->arrayContext != NULL)
493 : 2283 : MemoryContextDelete(so->arrayContext);
494 [ + + ]: 6684294 : if (so->killedItems != NULL)
495 : 85767 : pfree(so->killedItems);
5081 496 [ + + ]: 6684294 : if (so->currTuples != NULL)
497 : 66792 : pfree(so->currTuples);
498 : : /* so->markTuples should not be pfree'd, see btrescan */
10226 bruce@momjian.us 499 : 6684294 : pfree(so);
10651 scrappy@hub.org 500 : 6684294 : }
501 : :
502 : : /*
503 : : * btmarkpos() -- save current scan position
504 : : */
505 : : void
3520 tgl@sss.pgh.pa.us 506 : 65048 : btmarkpos(IndexScanDesc scan)
507 : : {
7062 508 : 65048 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
509 : :
510 : : /* There may be an old mark with a pin (but no lock). */
3818 kgrittn@postgresql.o 511 [ + + - + : 65048 : BTScanPosUnpinIfPinned(so->markPos);
+ + ]
512 : :
513 : : /*
514 : : * Just record the current itemIndex. If we later step to next page
515 : : * before releasing the marked position, _bt_steppage makes a full copy of
516 : : * the currPos struct in markPos. If (as often happens) the mark is moved
517 : : * before we leave the page, we don't have to do that work.
518 : : */
7062 tgl@sss.pgh.pa.us 519 [ - + - - : 65048 : if (BTScanPosIsValid(so->currPos))
+ - ]
6953 520 : 65048 : so->markItemIndex = so->currPos.itemIndex;
521 : : else
522 : : {
3818 kgrittn@postgresql.o 523 :UBC 0 : BTScanPosInvalidate(so->markPos);
6953 tgl@sss.pgh.pa.us 524 : 0 : so->markItemIndex = -1;
525 : : }
10651 scrappy@hub.org 526 :CBC 65048 : }
527 : :
528 : : /*
529 : : * btrestrpos() -- restore scan to last saved position
530 : : */
531 : : void
3520 tgl@sss.pgh.pa.us 532 : 27009 : btrestrpos(IndexScanDesc scan)
533 : : {
7062 534 : 27009 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
535 : :
6953 536 [ + + ]: 27009 : if (so->markItemIndex >= 0)
537 : : {
538 : : /*
539 : : * The scan has never moved to a new page since the last mark. Just
540 : : * restore the itemIndex.
541 : : *
542 : : * NB: In this case we can't count on anything in so->markPos to be
543 : : * accurate.
544 : : */
545 : 26955 : so->currPos.itemIndex = so->markItemIndex;
546 : : }
547 : : else
548 : : {
549 : : /*
550 : : * The scan moved to a new page after last mark or restore, and we are
551 : : * now restoring to the marked page. We aren't holding any read
552 : : * locks, but if we're still holding the pin for the current position,
553 : : * we must drop it.
554 : : */
555 [ - + - - : 54 : if (BTScanPosIsValid(so->currPos))
+ - ]
556 : : {
557 : : /* Before leaving current page, deal with any killed items */
3818 kgrittn@postgresql.o 558 [ - + ]: 54 : if (so->numKilled > 0)
3818 kgrittn@postgresql.o 559 :UBC 0 : _bt_killitems(scan);
3818 kgrittn@postgresql.o 560 [ - + - - :CBC 54 : BTScanPosUnpinIfPinned(so->currPos);
- + ]
561 : : }
562 : :
6953 tgl@sss.pgh.pa.us 563 [ - + - - : 54 : if (BTScanPosIsValid(so->markPos))
+ - ]
564 : : {
565 : : /* bump pin on mark buffer for assignment to current buffer */
3818 kgrittn@postgresql.o 566 [ - + - - : 54 : if (BTScanPosIsPinned(so->markPos))
- + ]
3818 kgrittn@postgresql.o 567 :UBC 0 : IncrBufferRefCount(so->markPos.buf);
6953 tgl@sss.pgh.pa.us 568 :CBC 54 : memcpy(&so->currPos, &so->markPos,
569 : : offsetof(BTScanPosData, items[1]) +
570 : 54 : so->markPos.lastItem * sizeof(BTScanPosItem));
5081 571 [ - + ]: 54 : if (so->currTuples)
5081 tgl@sss.pgh.pa.us 572 :UBC 0 : memcpy(so->currTuples, so->markTuples,
573 : 0 : so->markPos.nextTupleOffset);
574 : : /* Reset the scan's array keys (see _bt_steppage for why) */
518 pg@bowt.ie 575 [ - + ]:CBC 54 : if (so->numArrayKeys)
576 : : {
518 pg@bowt.ie 577 :UBC 0 : _bt_start_array_keys(scan, so->currPos.dir);
578 : 0 : so->needPrimScan = false;
579 : : }
580 : : }
581 : : else
3818 kgrittn@postgresql.o 582 : 0 : BTScanPosInvalidate(so->currPos);
583 : : }
10651 scrappy@hub.org 584 :CBC 27009 : }
585 : :
586 : : /*
587 : : * btestimateparallelscan -- estimate storage for BTParallelScanDescData
588 : : */
589 : : Size
155 pg@bowt.ie 590 : 32 : btestimateparallelscan(Relation rel, int nkeys, int norderbys)
591 : : {
592 : 32 : int16 nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
593 : : Size estnbtreeshared,
594 : : genericattrspace;
595 : :
596 : : /*
597 : : * Pessimistically assume that every input scan key will be output with
598 : : * its own SAOP array
599 : : */
600 : 32 : estnbtreeshared = offsetof(BTParallelScanDescData, btps_arrElems) +
601 : : sizeof(int) * nkeys;
602 : :
603 : : /* Single column indexes cannot possibly use a skip array */
604 [ + + ]: 32 : if (nkeyatts == 1)
605 : 23 : return estnbtreeshared;
606 : :
607 : : /*
608 : : * Pessimistically assume that all attributes prior to the least
609 : : * significant attribute require a skip array (and an associated key)
610 : : */
611 : 9 : genericattrspace = datumEstimateSpace((Datum) 0, false, true,
612 : : sizeof(Datum));
613 [ + + ]: 18 : for (int attnum = 1; attnum < nkeyatts; attnum++)
614 : : {
615 : : CompactAttribute *attr;
616 : :
617 : : /*
618 : : * We make the conservative assumption that every index column will
619 : : * also require a skip array.
620 : : *
621 : : * Every skip array must have space to store its scan key's sk_flags.
622 : : */
623 : 9 : estnbtreeshared = add_size(estnbtreeshared, sizeof(int));
624 : :
625 : : /* Consider space required to store a datum of opclass input type */
626 : 9 : attr = TupleDescCompactAttr(rel->rd_att, attnum - 1);
627 [ + - ]: 9 : if (attr->attbyval)
628 : 9 : {
629 : : /* This index attribute stores pass-by-value datums */
630 : 9 : Size estfixed = datumEstimateSpace((Datum) 0, false,
631 : 9 : true, attr->attlen);
632 : :
633 : 9 : estnbtreeshared = add_size(estnbtreeshared, estfixed);
634 : 9 : continue;
635 : : }
636 : :
637 : : /*
638 : : * This index attribute stores pass-by-reference datums.
639 : : *
640 : : * Assume that serializing this array will use just as much space as a
641 : : * pass-by-value datum, in addition to space for the largest possible
642 : : * whole index tuple (this is not just a per-datum portion of the
643 : : * largest possible tuple because that'd be almost as large anyway).
644 : : *
645 : : * This is quite conservative, but it's not clear how we could do much
646 : : * better. The executor requires an up-front storage request size
647 : : * that reliably covers the scan's high watermark memory usage. We
648 : : * can't be sure of the real high watermark until the scan is over.
649 : : */
155 pg@bowt.ie 650 :UBC 0 : estnbtreeshared = add_size(estnbtreeshared, genericattrspace);
651 : 0 : estnbtreeshared = add_size(estnbtreeshared, BTMaxItemSize);
652 : : }
653 : :
155 pg@bowt.ie 654 :CBC 9 : return estnbtreeshared;
655 : : }
656 : :
657 : : /*
658 : : * _bt_parallel_serialize_arrays() -- Serialize parallel array state.
659 : : *
660 : : * Caller must have exclusively locked btscan->btps_lock when called.
661 : : */
662 : : static void
663 : 18 : _bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
664 : : BTScanOpaque so)
665 : : {
666 : : char *datumshared;
667 : :
668 : : /* Space for serialized datums begins immediately after btps_arrElems[] */
669 : 18 : datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
670 [ + + ]: 36 : for (int i = 0; i < so->numArrayKeys; i++)
671 : : {
672 : 18 : BTArrayKeyInfo *array = &so->arrayKeys[i];
673 : 18 : ScanKey skey = &so->keyData[array->scan_key];
674 : :
675 [ + - ]: 18 : if (array->num_elems != -1)
676 : : {
677 : : /* Save SAOP array's cur_elem (no need to copy key/datum) */
678 [ - + ]: 18 : Assert(!(skey->sk_flags & SK_BT_SKIP));
679 : 18 : btscan->btps_arrElems[i] = array->cur_elem;
680 : 18 : continue;
681 : : }
682 : :
683 : : /* Save all mutable state associated with skip array's key */
155 pg@bowt.ie 684 [ # # ]:UBC 0 : Assert(skey->sk_flags & SK_BT_SKIP);
685 : 0 : memcpy(datumshared, &skey->sk_flags, sizeof(int));
686 : 0 : datumshared += sizeof(int);
687 : :
688 [ # # ]: 0 : if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
689 : : {
690 : : /* No sk_argument datum to serialize */
691 [ # # ]: 0 : Assert(skey->sk_argument == 0);
692 : 0 : continue;
693 : : }
694 : :
695 : 0 : datumSerialize(skey->sk_argument, (skey->sk_flags & SK_ISNULL) != 0,
696 : 0 : array->attbyval, array->attlen, &datumshared);
697 : : }
155 pg@bowt.ie 698 :CBC 18 : }
699 : :
700 : : /*
701 : : * _bt_parallel_restore_arrays() -- Restore serialized parallel array state.
702 : : *
703 : : * Caller must have exclusively locked btscan->btps_lock when called.
704 : : */
705 : : static void
706 : 18 : _bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
707 : : BTScanOpaque so)
708 : : {
709 : : char *datumshared;
710 : :
711 : : /* Space for serialized datums begins immediately after btps_arrElems[] */
712 : 18 : datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
713 [ + + ]: 36 : for (int i = 0; i < so->numArrayKeys; i++)
714 : : {
715 : 18 : BTArrayKeyInfo *array = &so->arrayKeys[i];
716 : 18 : ScanKey skey = &so->keyData[array->scan_key];
717 : : bool isnull;
718 : :
719 [ + - ]: 18 : if (array->num_elems != -1)
720 : : {
721 : : /* Restore SAOP array using its saved cur_elem */
722 [ - + ]: 18 : Assert(!(skey->sk_flags & SK_BT_SKIP));
723 : 18 : array->cur_elem = btscan->btps_arrElems[i];
724 : 18 : skey->sk_argument = array->elem_values[array->cur_elem];
725 : 18 : continue;
726 : : }
727 : :
728 : : /* Restore skip array by restoring its key directly */
155 pg@bowt.ie 729 [ # # # # ]:UBC 0 : if (!array->attbyval && skey->sk_argument)
730 : 0 : pfree(DatumGetPointer(skey->sk_argument));
731 : 0 : skey->sk_argument = (Datum) 0;
732 : 0 : memcpy(&skey->sk_flags, datumshared, sizeof(int));
733 : 0 : datumshared += sizeof(int);
734 : :
735 [ # # ]: 0 : Assert(skey->sk_flags & SK_BT_SKIP);
736 : :
737 [ # # ]: 0 : if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
738 : : {
739 : : /* No sk_argument datum to restore */
740 : 0 : continue;
741 : : }
742 : :
743 : 0 : skey->sk_argument = datumRestore(&datumshared, &isnull);
744 [ # # ]: 0 : if (isnull)
745 : : {
746 [ # # ]: 0 : Assert(skey->sk_argument == 0);
747 [ # # ]: 0 : Assert(skey->sk_flags & SK_SEARCHNULL);
748 [ # # ]: 0 : Assert(skey->sk_flags & SK_ISNULL);
749 : : }
750 : : }
3125 rhaas@postgresql.org 751 :CBC 18 : }
752 : :
753 : : /*
754 : : * btinitparallelscan -- initialize BTParallelScanDesc for parallel btree scan
755 : : */
756 : : void
757 : 32 : btinitparallelscan(void *target)
758 : : {
759 : 32 : BTParallelScanDesc bt_target = (BTParallelScanDesc) target;
760 : :
182 pg@bowt.ie 761 : 32 : LWLockInitialize(&bt_target->btps_lock,
762 : : LWTRANCHE_PARALLEL_BTREE_SCAN);
323 763 : 32 : bt_target->btps_nextScanPage = InvalidBlockNumber;
764 : 32 : bt_target->btps_lastCurrPage = InvalidBlockNumber;
3125 rhaas@postgresql.org 765 : 32 : bt_target->btps_pageStatus = BTPARALLEL_NOT_INITIALIZED;
766 : 32 : ConditionVariableInit(&bt_target->btps_cv);
767 : 32 : }
768 : :
769 : : /*
770 : : * btparallelrescan() -- reset parallel scan
771 : : */
772 : : void
773 : 12 : btparallelrescan(IndexScanDesc scan)
774 : : {
775 : : BTParallelScanDesc btscan;
776 : 12 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
777 : :
778 [ - + ]: 12 : Assert(parallel_scan);
779 : :
282 peter@eisentraut.org 780 : 12 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
781 : : parallel_scan->ps_offset_am);
782 : :
783 : : /*
784 : : * In theory, we don't need to acquire the LWLock here, because there
785 : : * shouldn't be any other workers running at this point, but we do so for
786 : : * consistency.
787 : : */
182 pg@bowt.ie 788 : 12 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
323 789 : 12 : btscan->btps_nextScanPage = InvalidBlockNumber;
790 : 12 : btscan->btps_lastCurrPage = InvalidBlockNumber;
3125 rhaas@postgresql.org 791 : 12 : btscan->btps_pageStatus = BTPARALLEL_NOT_INITIALIZED;
182 pg@bowt.ie 792 : 12 : LWLockRelease(&btscan->btps_lock);
3125 rhaas@postgresql.org 793 : 12 : }
794 : :
795 : : /*
796 : : * _bt_parallel_seize() -- Begin the process of advancing the scan to a new
797 : : * page. Other scans must wait until we call _bt_parallel_release()
798 : : * or _bt_parallel_done().
799 : : *
800 : : * The return value is true if we successfully seized the scan and false
801 : : * if we did not. The latter case occurs when no pages remain, or when
802 : : * another primitive index scan is scheduled that caller's backend cannot
803 : : * start just yet (only backends that call from _bt_first are capable of
804 : : * starting primitive index scans, which they indicate by passing first=true).
805 : : *
806 : : * If the return value is true, *next_scan_page returns the next page of the
807 : : * scan, and *last_curr_page returns the page that *next_scan_page came from.
808 : : * An invalid *next_scan_page means the scan hasn't yet started, or that
809 : : * caller needs to start the next primitive index scan (if it's the latter
810 : : * case we'll set so.needPrimScan).
811 : : *
812 : : * Callers should ignore the value of *next_scan_page and *last_curr_page if
813 : : * the return value is false.
814 : : */
815 : : bool
323 pg@bowt.ie 816 : 829 : _bt_parallel_seize(IndexScanDesc scan, BlockNumber *next_scan_page,
817 : : BlockNumber *last_curr_page, bool first)
818 : : {
155 819 : 829 : Relation rel = scan->indexRelation;
3125 rhaas@postgresql.org 820 : 829 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
302 pg@bowt.ie 821 : 829 : bool exit_loop = false,
822 : 829 : status = true,
823 : 829 : endscan = false;
3125 rhaas@postgresql.org 824 : 829 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
825 : : BTParallelScanDesc btscan;
826 : :
302 pg@bowt.ie 827 : 829 : *next_scan_page = InvalidBlockNumber;
323 828 : 829 : *last_curr_page = InvalidBlockNumber;
829 : :
830 : : /*
831 : : * Reset so->currPos, and initialize moreLeft/moreRight such that the next
832 : : * call to _bt_readnextpage treats this backend similarly to a serial
833 : : * backend that steps from *last_curr_page to *next_scan_page (unless this
834 : : * backend's so->currPos is initialized by _bt_readfirstpage before then).
835 : : */
836 : 829 : BTScanPosInvalidate(so->currPos);
837 : 829 : so->currPos.moreLeft = so->currPos.moreRight = true;
838 : :
518 839 [ + + ]: 829 : if (first)
840 : : {
841 : : /*
842 : : * Initialize array related state when called from _bt_first, assuming
843 : : * that this will be the first primitive index scan for the scan
844 : : */
845 : 223 : so->needPrimScan = false;
846 : 223 : so->scanBehind = false;
325 847 : 223 : so->oppositeDirCheck = false;
848 : : }
849 : : else
850 : : {
851 : : /*
852 : : * Don't attempt to seize the scan when it requires another primitive
853 : : * index scan, since caller's backend cannot start it right now
854 : : */
518 855 [ - + ]: 606 : if (so->needPrimScan)
518 pg@bowt.ie 856 :UBC 0 : return false;
857 : : }
858 : :
282 peter@eisentraut.org 859 :CBC 829 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
860 : : parallel_scan->ps_offset_am);
861 : :
862 : : while (1)
863 : : {
182 pg@bowt.ie 864 : 831 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
865 : :
518 866 [ + + ]: 831 : if (btscan->btps_pageStatus == BTPARALLEL_DONE)
867 : : {
868 : : /* We're done with this parallel index scan */
3125 rhaas@postgresql.org 869 : 146 : status = false;
870 : : }
302 pg@bowt.ie 871 [ + + ]: 685 : else if (btscan->btps_pageStatus == BTPARALLEL_IDLE &&
872 [ + + ]: 621 : btscan->btps_nextScanPage == P_NONE)
873 : : {
874 : : /* End this parallel index scan */
875 : 14 : status = false;
876 : 14 : endscan = true;
877 : : }
518 878 [ + + ]: 671 : else if (btscan->btps_pageStatus == BTPARALLEL_NEED_PRIMSCAN)
879 : : {
880 [ - + ]: 18 : Assert(so->numArrayKeys);
881 : :
882 [ + - ]: 18 : if (first)
883 : : {
884 : : /* Can start scheduled primitive scan right away, so do so */
885 : 18 : btscan->btps_pageStatus = BTPARALLEL_ADVANCING;
886 : :
887 : : /* Restore scan's array keys from serialized values */
155 888 : 18 : _bt_parallel_restore_arrays(rel, btscan, so);
518 889 : 18 : exit_loop = true;
890 : : }
891 : : else
892 : : {
893 : : /*
894 : : * Don't attempt to seize the scan when it requires another
895 : : * primitive index scan, since caller's backend cannot start
896 : : * it right now
897 : : */
354 pg@bowt.ie 898 :UBC 0 : status = false;
899 : : }
900 : :
901 : : /*
902 : : * Either way, update backend local state to indicate that a
903 : : * pending primitive scan is required
904 : : */
354 pg@bowt.ie 905 :CBC 18 : so->needPrimScan = true;
906 : 18 : so->scanBehind = false;
325 907 : 18 : so->oppositeDirCheck = false;
908 : : }
518 909 [ + + ]: 653 : else if (btscan->btps_pageStatus != BTPARALLEL_ADVANCING)
910 : : {
911 : : /*
912 : : * We have successfully seized control of the scan for the purpose
913 : : * of advancing it to a new page!
914 : : */
3125 rhaas@postgresql.org 915 : 651 : btscan->btps_pageStatus = BTPARALLEL_ADVANCING;
302 pg@bowt.ie 916 [ - + ]: 651 : Assert(btscan->btps_nextScanPage != P_NONE);
323 917 : 651 : *next_scan_page = btscan->btps_nextScanPage;
918 : 651 : *last_curr_page = btscan->btps_lastCurrPage;
3125 rhaas@postgresql.org 919 : 651 : exit_loop = true;
920 : : }
182 pg@bowt.ie 921 : 831 : LWLockRelease(&btscan->btps_lock);
3125 rhaas@postgresql.org 922 [ + + + + ]: 831 : if (exit_loop || !status)
923 : : break;
924 : 2 : ConditionVariableSleep(&btscan->btps_cv, WAIT_EVENT_BTREE_PAGE);
925 : : }
926 : 829 : ConditionVariableCancelSleep();
927 : :
928 : : /* When the scan has reached the rightmost (or leftmost) page, end it */
302 pg@bowt.ie 929 [ + + ]: 829 : if (endscan)
930 : 14 : _bt_parallel_done(scan);
931 : :
3125 rhaas@postgresql.org 932 : 829 : return status;
933 : : }
934 : :
935 : : /*
936 : : * _bt_parallel_release() -- Complete the process of advancing the scan to a
937 : : * new page. We now have the new value btps_nextScanPage; another backend
938 : : * can now begin advancing the scan.
939 : : *
940 : : * Callers whose scan uses array keys must save their curr_page argument so
941 : : * that it can be passed to _bt_parallel_primscan_schedule, should caller
942 : : * determine that another primitive index scan is required.
943 : : *
944 : : * If caller's next_scan_page is P_NONE, the scan has reached the index's
945 : : * rightmost/leftmost page. This is treated as reaching the end of the scan
946 : : * within _bt_parallel_seize.
947 : : *
948 : : * Note: unlike the serial case, parallel scans don't need to remember both
949 : : * sibling links. next_scan_page is whichever link is next given the scan's
950 : : * direction. That's all we'll ever need, since the direction of a parallel
951 : : * scan can never change.
952 : : */
953 : : void
323 pg@bowt.ie 954 : 669 : _bt_parallel_release(IndexScanDesc scan, BlockNumber next_scan_page,
955 : : BlockNumber curr_page)
956 : : {
3125 rhaas@postgresql.org 957 : 669 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
958 : : BTParallelScanDesc btscan;
959 : :
302 pg@bowt.ie 960 [ - + ]: 669 : Assert(BlockNumberIsValid(next_scan_page));
961 : :
282 peter@eisentraut.org 962 : 669 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
963 : : parallel_scan->ps_offset_am);
964 : :
182 pg@bowt.ie 965 : 669 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
323 966 : 669 : btscan->btps_nextScanPage = next_scan_page;
967 : 669 : btscan->btps_lastCurrPage = curr_page;
3125 rhaas@postgresql.org 968 : 669 : btscan->btps_pageStatus = BTPARALLEL_IDLE;
182 pg@bowt.ie 969 : 669 : LWLockRelease(&btscan->btps_lock);
3125 rhaas@postgresql.org 970 : 669 : ConditionVariableSignal(&btscan->btps_cv);
971 : 669 : }
972 : :
973 : : /*
974 : : * _bt_parallel_done() -- Mark the parallel scan as complete.
975 : : *
976 : : * When there are no pages left to scan, this function should be called to
977 : : * notify other workers. Otherwise, they might wait forever for the scan to
978 : : * advance to the next page.
979 : : */
980 : : void
981 : 3391574 : _bt_parallel_done(IndexScanDesc scan)
982 : : {
354 pg@bowt.ie 983 : 3391574 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
3125 rhaas@postgresql.org 984 : 3391574 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
985 : : BTParallelScanDesc btscan;
986 : 3391574 : bool status_changed = false;
987 : :
306 pg@bowt.ie 988 [ + - - + : 3391574 : Assert(!BTScanPosIsValid(so->currPos));
- + ]
989 : :
990 : : /* Do nothing, for non-parallel scans */
3125 rhaas@postgresql.org 991 [ + + ]: 3391574 : if (parallel_scan == NULL)
992 : 3391485 : return;
993 : :
994 : : /*
995 : : * Should not mark parallel scan done when there's still a pending
996 : : * primitive index scan
997 : : */
354 pg@bowt.ie 998 [ + + ]: 89 : if (so->needPrimScan)
999 : 18 : return;
1000 : :
282 peter@eisentraut.org 1001 : 71 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
1002 : : parallel_scan->ps_offset_am);
1003 : :
1004 : : /*
1005 : : * Mark the parallel scan as done, unless some other process did so
1006 : : * already
1007 : : */
182 pg@bowt.ie 1008 : 71 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
354 1009 [ - + ]: 71 : Assert(btscan->btps_pageStatus != BTPARALLEL_NEED_PRIMSCAN);
518 1010 [ + + ]: 71 : if (btscan->btps_pageStatus != BTPARALLEL_DONE)
1011 : : {
3125 rhaas@postgresql.org 1012 : 44 : btscan->btps_pageStatus = BTPARALLEL_DONE;
1013 : 44 : status_changed = true;
1014 : : }
182 pg@bowt.ie 1015 : 71 : LWLockRelease(&btscan->btps_lock);
1016 : :
1017 : : /* wake up all the workers associated with this parallel scan */
3125 rhaas@postgresql.org 1018 [ + + ]: 71 : if (status_changed)
1019 : 44 : ConditionVariableBroadcast(&btscan->btps_cv);
1020 : : }
1021 : :
1022 : : /*
1023 : : * _bt_parallel_primscan_schedule() -- Schedule another primitive index scan.
1024 : : *
1025 : : * Caller passes the curr_page most recently passed to _bt_parallel_release
1026 : : * by its backend. Caller successfully schedules the next primitive index scan
1027 : : * if the shared parallel state hasn't been seized since caller's backend last
1028 : : * advanced the scan.
1029 : : */
1030 : : void
323 pg@bowt.ie 1031 : 18 : _bt_parallel_primscan_schedule(IndexScanDesc scan, BlockNumber curr_page)
1032 : : {
155 1033 : 18 : Relation rel = scan->indexRelation;
3125 rhaas@postgresql.org 1034 : 18 : BTScanOpaque so = (BTScanOpaque) scan->opaque;
1035 : 18 : ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
1036 : : BTParallelScanDesc btscan;
1037 : :
518 pg@bowt.ie 1038 [ - + ]: 18 : Assert(so->numArrayKeys);
1039 : :
282 peter@eisentraut.org 1040 : 18 : btscan = (BTParallelScanDesc) OffsetToPointer(parallel_scan,
1041 : : parallel_scan->ps_offset_am);
1042 : :
182 pg@bowt.ie 1043 : 18 : LWLockAcquire(&btscan->btps_lock, LW_EXCLUSIVE);
323 1044 [ + - ]: 18 : if (btscan->btps_lastCurrPage == curr_page &&
518 1045 [ + - ]: 18 : btscan->btps_pageStatus == BTPARALLEL_IDLE)
1046 : : {
323 1047 : 18 : btscan->btps_nextScanPage = InvalidBlockNumber;
1048 : 18 : btscan->btps_lastCurrPage = InvalidBlockNumber;
518 1049 : 18 : btscan->btps_pageStatus = BTPARALLEL_NEED_PRIMSCAN;
1050 : :
1051 : : /* Serialize scan's current array keys */
155 1052 : 18 : _bt_parallel_serialize_arrays(rel, btscan, so);
1053 : : }
182 1054 : 18 : LWLockRelease(&btscan->btps_lock);
3125 rhaas@postgresql.org 1055 : 18 : }
1056 : :
1057 : : /*
1058 : : * Bulk deletion of all index entries pointing to a set of heap tuples.
1059 : : * The set of target tuples is specified via a callback routine that tells
1060 : : * whether any given heap tuple (identified by ItemPointer) is being deleted.
1061 : : *
1062 : : * Result: a palloc'd struct containing statistical info for VACUUM displays.
1063 : : */
1064 : : IndexBulkDeleteResult *
3520 tgl@sss.pgh.pa.us 1065 : 1521 : btbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
1066 : : IndexBulkDeleteCallback callback, void *callback_state)
1067 : : {
7067 1068 : 1521 : Relation rel = info->index;
1069 : : BTCycleId cycleid;
1070 : :
1071 : : /* allocate stats if first time through, else re-use existing struct */
7061 1072 [ + + ]: 1521 : if (stats == NULL)
1073 : 1503 : stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
1074 : :
1075 : : /* Establish the vacuum cycle ID to use for this scan */
1076 : : /* The ENSURE stuff ensures we clean up shared memory on failure */
6352 1077 [ + - ]: 1521 : PG_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
1078 : : {
7061 1079 : 1521 : cycleid = _bt_start_vacuum(rel);
1080 : :
1954 pg@bowt.ie 1081 : 1521 : btvacuumscan(info, stats, callback, callback_state, cycleid);
1082 : : }
6352 tgl@sss.pgh.pa.us 1083 [ - + ]: 1521 : PG_END_ENSURE_ERROR_CLEANUP(_bt_end_vacuum_callback, PointerGetDatum(rel));
1084 : 1521 : _bt_end_vacuum(rel);
1085 : :
3520 1086 : 1521 : return stats;
1087 : : }
1088 : :
1089 : : /*
1090 : : * Post-VACUUM cleanup.
1091 : : *
1092 : : * Result: a palloc'd struct containing statistical info for VACUUM displays.
1093 : : */
1094 : : IndexBulkDeleteResult *
1095 : 27093 : btvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
1096 : : {
1097 : : BlockNumber num_delpages;
1098 : :
1099 : : /* No-op in ANALYZE ONLY mode */
6010 1100 [ + + ]: 27093 : if (info->analyze_only)
3520 1101 : 8812 : return stats;
1102 : :
1103 : : /*
1104 : : * If btbulkdelete was called, we need not do anything (we just maintain
1105 : : * the information used within _bt_vacuum_needs_cleanup() by calling
1106 : : * _bt_set_cleanup_info() below).
1107 : : *
1108 : : * If btbulkdelete was _not_ called, then we have a choice to make: we
1109 : : * must decide whether or not a btvacuumscan() call is needed now (i.e.
1110 : : * whether the ongoing VACUUM operation can entirely avoid a physical scan
1111 : : * of the index). A call to _bt_vacuum_needs_cleanup() decides it for us
1112 : : * now.
1113 : : */
7067 1114 [ + + ]: 18281 : if (stats == NULL)
1115 : : {
1116 : : /* Check if VACUUM operation can entirely avoid btvacuumscan() call */
819 pg@bowt.ie 1117 [ + + ]: 17062 : if (!_bt_vacuum_needs_cleanup(info->index))
2712 teodor@sigaev.ru 1118 : 17054 : return NULL;
1119 : :
1120 : : /*
1121 : : * Since we aren't going to actually delete any leaf items, there's no
1122 : : * need to go through all the vacuum-cycle-ID pushups here.
1123 : : *
1124 : : * Posting list tuples are a source of inaccuracy for cleanup-only
1125 : : * scans. btvacuumscan() will assume that the number of index tuples
1126 : : * from each page can be used as num_index_tuples, even though
1127 : : * num_index_tuples is supposed to represent the number of TIDs in the
1128 : : * index. This naive approach can underestimate the number of tuples
1129 : : * in the index significantly.
1130 : : *
1131 : : * We handle the problem by making num_index_tuples an estimate in
1132 : : * cleanup-only case.
1133 : : */
7067 tgl@sss.pgh.pa.us 1134 : 8 : stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
1954 pg@bowt.ie 1135 : 8 : btvacuumscan(info, stats, NULL, NULL, 0);
1641 1136 : 8 : stats->estimated_count = true;
1137 : : }
1138 : :
1139 : : /*
1140 : : * Maintain num_delpages value in metapage for _bt_vacuum_needs_cleanup().
1141 : : *
1142 : : * num_delpages is the number of deleted pages now in the index that were
1143 : : * not safe to place in the FSM to be recycled just yet. num_delpages is
1144 : : * greater than 0 only when _bt_pagedel() actually deleted pages during
1145 : : * our call to btvacuumscan(). Even then, _bt_pendingfsm_finalize() must
1146 : : * have failed to place any newly deleted pages in the FSM just moments
1147 : : * ago. (Actually, there are edge cases where recycling of the current
1148 : : * VACUUM's newly deleted pages does not even become safe by the time the
1149 : : * next VACUUM comes around. See nbtree/README.)
1150 : : */
1655 1151 [ - + ]: 1227 : Assert(stats->pages_deleted >= stats->pages_free);
1152 : 1227 : num_delpages = stats->pages_deleted - stats->pages_free;
819 1153 : 1227 : _bt_set_cleanup_info(info->index, num_delpages);
1154 : :
1155 : : /*
1156 : : * It's quite possible for us to be fooled by concurrent page splits into
1157 : : * double-counting some index tuples, so disbelieve any total that exceeds
1158 : : * the underlying heap's count ... if we know that accurately. Otherwise
1159 : : * this might just make matters worse.
1160 : : */
5689 tgl@sss.pgh.pa.us 1161 [ + + ]: 1227 : if (!info->estimated_count)
1162 : : {
7061 1163 [ + + ]: 1189 : if (stats->num_index_tuples > info->num_heap_tuples)
1164 : 34 : stats->num_index_tuples = info->num_heap_tuples;
1165 : : }
1166 : :
3520 1167 : 1227 : return stats;
1168 : : }
1169 : :
1170 : : /*
1171 : : * btvacuumscan --- scan the index for VACUUMing purposes
1172 : : *
1173 : : * This combines the functions of looking for leaf tuples that are deletable
1174 : : * according to the vacuum callback, looking for empty pages that can be
1175 : : * deleted, and looking for old deleted pages that can be recycled. Both
1176 : : * btbulkdelete and btvacuumcleanup invoke this (the latter only if no
1177 : : * btbulkdelete call occurred and _bt_vacuum_needs_cleanup returned true).
1178 : : *
1179 : : * The caller is responsible for initially allocating/zeroing a stats struct
1180 : : * and for obtaining a vacuum cycle ID if necessary.
1181 : : */
1182 : : static void
7061 1183 : 1529 : btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
1184 : : IndexBulkDeleteCallback callback, void *callback_state,
1185 : : BTCycleId cycleid)
1186 : : {
1187 : 1529 : Relation rel = info->index;
1188 : : BTVacState vstate;
1189 : : BlockNumber num_pages;
1190 : : bool needLock;
1191 : : BlockRangeReadStreamPrivate p;
169 melanieplageman@gmai 1192 : 1529 : ReadStream *stream = NULL;
1193 : :
1194 : : /*
1195 : : * Reset fields that track information about the entire index now. This
1196 : : * avoids double-counting in the case where a single VACUUM command
1197 : : * requires multiple scans of the index.
1198 : : *
1199 : : * Avoid resetting the tuples_removed and pages_newly_deleted fields here,
1200 : : * since they track information about the VACUUM command, and so must last
1201 : : * across each call to btvacuumscan().
1202 : : *
1203 : : * (Note that pages_free is treated as state about the whole index, not
1204 : : * the current VACUUM. This is appropriate because RecordFreeIndexPage()
1205 : : * calls are idempotent, and get repeated for the same deleted pages in
1206 : : * some scenarios. The point for us is to track the number of recyclable
1207 : : * pages in the index at the end of the VACUUM command.)
1208 : : */
1655 pg@bowt.ie 1209 : 1529 : stats->num_pages = 0;
7061 tgl@sss.pgh.pa.us 1210 : 1529 : stats->num_index_tuples = 0;
1211 : 1529 : stats->pages_deleted = 0;
1655 pg@bowt.ie 1212 : 1529 : stats->pages_free = 0;
1213 : :
1214 : : /* Set up info to pass down to btvacuumpage */
7061 tgl@sss.pgh.pa.us 1215 : 1529 : vstate.info = info;
1216 : 1529 : vstate.stats = stats;
1217 : 1529 : vstate.callback = callback;
1218 : 1529 : vstate.callback_state = callback_state;
1219 : 1529 : vstate.cycleid = cycleid;
1220 : :
1221 : : /* Create a temporary memory context to run _bt_pagedel in */
1222 : 1529 : vstate.pagedelcontext = AllocSetContextCreate(CurrentMemoryContext,
1223 : : "_bt_pagedel",
1224 : : ALLOCSET_DEFAULT_SIZES);
1225 : :
1226 : : /* Initialize vstate fields used by _bt_pendingfsm_finalize */
1630 pg@bowt.ie 1227 : 1529 : vstate.bufsize = 0;
1228 : 1529 : vstate.maxbufsize = 0;
1229 : 1529 : vstate.pendingpages = NULL;
1230 : 1529 : vstate.npendingpages = 0;
1231 : : /* Consider applying _bt_pendingfsm_finalize optimization */
1232 : 1529 : _bt_pendingfsm_init(rel, &vstate, (callback == NULL));
1233 : :
1234 : : /*
1235 : : * The outer loop iterates over all index pages except the metapage, in
1236 : : * physical order (we hope the kernel will cooperate in providing
1237 : : * read-ahead for speed). It is critical that we visit all leaf pages,
1238 : : * including ones added after we start the scan, else we might fail to
1239 : : * delete some deletable tuples. Hence, we must repeatedly check the
1240 : : * relation length. We must acquire the relation-extension lock while
1241 : : * doing so to avoid a race condition: if someone else is extending the
1242 : : * relation, there is a window where bufmgr/smgr have created a new
1243 : : * all-zero page but it hasn't yet been write-locked by _bt_getbuf(). If
1244 : : * we manage to scan such a page here, we'll improperly assume it can be
1245 : : * recycled. Taking the lock synchronizes things enough to prevent a
1246 : : * problem: either num_pages won't include the new page, or _bt_getbuf
1247 : : * already has write lock on the buffer and it will be fully initialized
1248 : : * before we can examine it. Also, we need not worry if a page is added
1249 : : * immediately after we look; the page splitting code already has
1250 : : * write-lock on the left page before it adds a right page, so we must
1251 : : * already have processed any tuples due to be moved into such a page.
1252 : : *
1253 : : * XXX: Now that new pages are locked with RBM_ZERO_AND_LOCK, I don't
1254 : : * think the use of the extension lock is still required.
1255 : : *
1256 : : * We can skip locking for new or temp relations, however, since no one
1257 : : * else could be accessing them.
1258 : : */
7061 tgl@sss.pgh.pa.us 1259 [ + + + - ]: 1529 : needLock = !RELATION_IS_LOCAL(rel);
1260 : :
169 melanieplageman@gmai 1261 : 1529 : p.current_blocknum = BTREE_METAPAGE + 1;
1262 : :
1263 : : /*
1264 : : * It is safe to use batchmode as block_range_read_stream_cb takes no
1265 : : * locks.
1266 : : */
131 1267 : 1529 : stream = read_stream_begin_relation(READ_STREAM_MAINTENANCE |
1268 : : READ_STREAM_FULL |
1269 : : READ_STREAM_USE_BATCHING,
1270 : : info->strategy,
1271 : : rel,
1272 : : MAIN_FORKNUM,
1273 : : block_range_read_stream_cb,
1274 : : &p,
1275 : : 0);
1276 : : for (;;)
1277 : : {
1278 : : /* Get the current relation length */
7061 tgl@sss.pgh.pa.us 1279 [ + + ]: 2926 : if (needLock)
1280 : 2924 : LockRelationForExtension(rel, ExclusiveLock);
1281 : 2926 : num_pages = RelationGetNumberOfBlocks(rel);
1282 [ + + ]: 2926 : if (needLock)
1283 : 2924 : UnlockRelationForExtension(rel, ExclusiveLock);
1284 : :
2349 alvherre@alvh.no-ip. 1285 [ + + ]: 2926 : if (info->report_progress)
1286 : 435 : pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_TOTAL,
1287 : : num_pages);
1288 : :
1289 : : /* Quit if we've scanned the whole relation */
169 melanieplageman@gmai 1290 [ + + ]: 2926 : if (p.current_blocknum >= num_pages)
7061 tgl@sss.pgh.pa.us 1291 : 1529 : break;
1292 : :
169 melanieplageman@gmai 1293 : 1397 : p.last_exclusive = num_pages;
1294 : :
1295 : : /* Iterate over pages, then loop back to recheck relation length */
1296 : : while (true)
7146 tgl@sss.pgh.pa.us 1297 : 15091 : {
1298 : : BlockNumber current_block;
1299 : : Buffer buf;
1300 : :
1301 : : /* call vacuum_delay_point while not holding any buffer lock */
169 melanieplageman@gmai 1302 : 16488 : vacuum_delay_point(false);
1303 : :
1304 : 16488 : buf = read_stream_next_buffer(stream, NULL);
1305 : :
1306 [ + + ]: 16488 : if (!BufferIsValid(buf))
1307 : 1397 : break;
1308 : :
1309 : 15091 : current_block = btvacuumpage(&vstate, buf);
1310 : :
2349 alvherre@alvh.no-ip. 1311 [ + + ]: 15091 : if (info->report_progress)
1312 : 472 : pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
1313 : : current_block);
1314 : : }
1315 : :
1316 : : /*
1317 : : * We have to reset the read stream to use it again. After returning
1318 : : * InvalidBuffer, the read stream API won't invoke our callback again
1319 : : * until the stream has been reset.
1320 : : */
169 melanieplageman@gmai 1321 : 1397 : read_stream_reset(stream);
1322 : : }
1323 : :
1324 : 1529 : read_stream_end(stream);
1325 : :
1326 : : /* Set statistics num_pages field to final size of index */
1655 pg@bowt.ie 1327 : 1529 : stats->num_pages = num_pages;
1328 : :
7061 tgl@sss.pgh.pa.us 1329 : 1529 : MemoryContextDelete(vstate.pagedelcontext);
1330 : :
1331 : : /*
1332 : : * If there were any calls to _bt_pagedel() during scan of the index then
1333 : : * see if any of the resulting pages can be placed in the FSM now. When
1334 : : * it's not safe we'll have to leave it up to a future VACUUM operation.
1335 : : *
1336 : : * Finally, if we placed any pages in the FSM (either just now or during
1337 : : * the scan), forcibly update the upper-level FSM pages to ensure that
1338 : : * searchers can find them.
1339 : : */
1630 pg@bowt.ie 1340 : 1529 : _bt_pendingfsm_finalize(rel, &vstate);
1655 1341 [ + + ]: 1529 : if (stats->pages_free > 0)
2717 tgl@sss.pgh.pa.us 1342 : 56 : IndexFreeSpaceMapVacuum(rel);
7061 1343 : 1529 : }
1344 : :
1345 : : /*
1346 : : * btvacuumpage --- VACUUM one page
1347 : : *
1348 : : * This processes a single page for btvacuumscan(). In some cases we must
1349 : : * backtrack to re-examine and VACUUM pages that were on buf's page during
1350 : : * a previous call here. This is how we handle page splits (that happened
1351 : : * after our cycleid was acquired) whose right half page happened to reuse
1352 : : * a block that we might have processed at some point before it was
1353 : : * recycled (i.e. before the page split).
1354 : : *
1355 : : * Returns BlockNumber of a scanned page (not backtracked).
1356 : : */
1357 : : static BlockNumber
169 melanieplageman@gmai 1358 : 15091 : btvacuumpage(BTVacState *vstate, Buffer buf)
1359 : : {
7061 tgl@sss.pgh.pa.us 1360 : 15091 : IndexVacuumInfo *info = vstate->info;
1361 : 15091 : IndexBulkDeleteResult *stats = vstate->stats;
1362 : 15091 : IndexBulkDeleteCallback callback = vstate->callback;
1363 : 15091 : void *callback_state = vstate->callback_state;
1364 : 15091 : Relation rel = info->index;
887 pg@bowt.ie 1365 : 15091 : Relation heaprel = info->heaprel;
1366 : : bool attempt_pagedel;
1367 : : BlockNumber blkno,
1368 : : backtrack_to;
169 melanieplageman@gmai 1369 : 15091 : BlockNumber scanblkno = BufferGetBlockNumber(buf);
1370 : : Page page;
1371 : : BTPageOpaque opaque;
1372 : :
1953 pg@bowt.ie 1373 : 15091 : blkno = scanblkno;
1374 : :
1375 : 15091 : backtrack:
1376 : :
1377 : 15091 : attempt_pagedel = false;
1378 : 15091 : backtrack_to = P_NONE;
1379 : :
1873 1380 : 15091 : _bt_lockbuf(rel, buf, BT_READ);
3426 kgrittn@postgresql.o 1381 : 15091 : page = BufferGetPage(buf);
1953 pg@bowt.ie 1382 : 15091 : opaque = NULL;
7061 tgl@sss.pgh.pa.us 1383 [ + - ]: 15091 : if (!PageIsNew(page))
1384 : : {
1385 : 15091 : _bt_checkpage(rel, buf);
1254 michael@paquier.xyz 1386 : 15091 : opaque = BTPageGetOpaque(page);
1387 : : }
1388 : :
1953 pg@bowt.ie 1389 [ - + ]: 15091 : Assert(blkno <= scanblkno);
1390 [ - + ]: 15091 : if (blkno != scanblkno)
1391 : : {
1392 : : /*
1393 : : * We're backtracking.
1394 : : *
1395 : : * We followed a right link to a sibling leaf page (a page that
1396 : : * happens to be from a block located before scanblkno). The only
1397 : : * case we want to do anything with is a live leaf page having the
1398 : : * current vacuum cycle ID.
1399 : : *
1400 : : * The page had better be in a state that's consistent with what we
1401 : : * expect. Check for conditions that imply corruption in passing. It
1402 : : * can't be half-dead because only an interrupted VACUUM process can
1403 : : * leave pages in that state, so we'd definitely have dealt with it
1404 : : * back when the page was the scanblkno page (half-dead pages are
1405 : : * always marked fully deleted by _bt_pagedel(), barring corruption).
1406 : : */
1953 pg@bowt.ie 1407 [ # # # # :UBC 0 : if (!opaque || !P_ISLEAF(opaque) || P_ISHALFDEAD(opaque))
# # ]
1408 : : {
1409 : 0 : Assert(false);
1410 : : ereport(LOG,
1411 : : (errcode(ERRCODE_INDEX_CORRUPTED),
1412 : : errmsg_internal("right sibling %u of scanblkno %u unexpectedly in an inconsistent state in index \"%s\"",
1413 : : blkno, scanblkno, RelationGetRelationName(rel))));
1414 : : _bt_relbuf(rel, buf);
1415 : : return scanblkno;
1416 : : }
1417 : :
1418 : : /*
1419 : : * We may have already processed the page in an earlier call, when the
1420 : : * page was scanblkno. This happens when the leaf page split occurred
1421 : : * after the scan began, but before the right sibling page became the
1422 : : * scanblkno.
1423 : : *
1424 : : * Page may also have been deleted by current btvacuumpage() call,
1425 : : * since _bt_pagedel() sometimes deletes the right sibling page of
1426 : : * scanblkno in passing (it does so after we decided where to
1427 : : * backtrack to). We don't need to process this page as a deleted
1428 : : * page a second time now (in fact, it would be wrong to count it as a
1429 : : * deleted page in the bulk delete statistics a second time).
1430 : : */
1431 [ # # # # ]: 0 : if (opaque->btpo_cycleid != vstate->cycleid || P_ISDELETED(opaque))
1432 : : {
1433 : : /* Done with current scanblkno (and all lower split pages) */
7061 tgl@sss.pgh.pa.us 1434 : 0 : _bt_relbuf(rel, buf);
169 melanieplageman@gmai 1435 : 0 : return scanblkno;
1436 : : }
1437 : : }
1438 : :
887 pg@bowt.ie 1439 [ + - + + ]:CBC 15091 : if (!opaque || BTPageIsRecyclable(page, heaprel))
1440 : : {
1441 : : /* Okay to recycle this page (which could be leaf or internal) */
6185 heikki.linnakangas@i 1442 : 1527 : RecordFreeIndexPage(rel, blkno);
7061 tgl@sss.pgh.pa.us 1443 : 1527 : stats->pages_deleted++;
1655 pg@bowt.ie 1444 : 1527 : stats->pages_free++;
1445 : : }
7061 tgl@sss.pgh.pa.us 1446 [ + + ]: 13564 : else if (P_ISDELETED(opaque))
1447 : : {
1448 : : /*
1449 : : * Already deleted page (which could be leaf or internal). Can't
1450 : : * recycle yet.
1451 : : */
1452 : 114 : stats->pages_deleted++;
1453 : : }
6884 1454 [ - + ]: 13450 : else if (P_ISHALFDEAD(opaque))
1455 : : {
1456 : : /* Half-dead leaf page (from interrupted VACUUM) -- finish deleting */
1654 pg@bowt.ie 1457 :UBC 0 : attempt_pagedel = true;
1458 : :
1459 : : /*
1460 : : * _bt_pagedel() will increment both pages_newly_deleted and
1461 : : * pages_deleted stats in all cases (barring corruption)
1462 : : */
1463 : : }
7061 tgl@sss.pgh.pa.us 1464 [ + + ]:CBC 13450 : else if (P_ISLEAF(opaque))
1465 : : {
1466 : : OffsetNumber deletable[MaxIndexTuplesPerPage];
1467 : : int ndeletable;
1468 : : BTVacuumPosting updatable[MaxIndexTuplesPerPage];
1469 : : int nupdatable;
1470 : : OffsetNumber offnum,
1471 : : minoff,
1472 : : maxoff;
1473 : : int nhtidsdead,
1474 : : nhtidslive;
1475 : :
1476 : : /*
1477 : : * Trade in the initial read lock for a full cleanup lock on this
1478 : : * page. We must get such a lock on every leaf page over the course
1479 : : * of the vacuum scan, whether or not it actually contains any
1480 : : * deletable tuples --- see nbtree/README.
1481 : : */
1873 pg@bowt.ie 1482 : 12628 : _bt_upgradelockbufcleanup(rel, buf);
1483 : :
1484 : : /*
1485 : : * Check whether we need to backtrack to earlier pages. What we are
1486 : : * concerned about is a page split that happened since we started the
1487 : : * vacuum scan. If the split moved tuples on the right half of the
1488 : : * split (i.e. the tuples that sort high) to a block that we already
1489 : : * passed over, then we might have missed the tuples. We need to
1490 : : * backtrack now. (Must do this before possibly clearing btpo_cycleid
1491 : : * or deleting scanblkno page below!)
1492 : : */
7061 tgl@sss.pgh.pa.us 1493 [ + + ]: 12628 : if (vstate->cycleid != 0 &&
1494 [ + + ]: 12550 : opaque->btpo_cycleid == vstate->cycleid &&
7061 tgl@sss.pgh.pa.us 1495 [ + + ]:GBC 2 : !(opaque->btpo_flags & BTP_SPLIT_END) &&
1496 [ + - ]: 1 : !P_RIGHTMOST(opaque) &&
1953 pg@bowt.ie 1497 [ - + ]: 1 : opaque->btpo_next < scanblkno)
1953 pg@bowt.ie 1498 :UBC 0 : backtrack_to = opaque->btpo_next;
1499 : :
7061 tgl@sss.pgh.pa.us 1500 :CBC 12628 : ndeletable = 0;
2019 pg@bowt.ie 1501 : 12628 : nupdatable = 0;
7061 tgl@sss.pgh.pa.us 1502 [ + + ]: 12628 : minoff = P_FIRSTDATAKEY(opaque);
1503 : 12628 : maxoff = PageGetMaxOffsetNumber(page);
2019 pg@bowt.ie 1504 : 12628 : nhtidsdead = 0;
1505 : 12628 : nhtidslive = 0;
7061 tgl@sss.pgh.pa.us 1506 [ + + ]: 12628 : if (callback)
1507 : : {
1508 : : /* btbulkdelete callback tells us what to delete (or update) */
1509 : 12550 : for (offnum = minoff;
1510 [ + + ]: 2436799 : offnum <= maxoff;
1511 : 2424249 : offnum = OffsetNumberNext(offnum))
1512 : : {
1513 : : IndexTuple itup;
1514 : :
1515 : 2424249 : itup = (IndexTuple) PageGetItem(page,
1516 : 2424249 : PageGetItemId(page, offnum));
1517 : :
2019 pg@bowt.ie 1518 [ - + ]: 2424249 : Assert(!BTreeTupleIsPivot(itup));
1519 [ + + ]: 2424249 : if (!BTreeTupleIsPosting(itup))
1520 : : {
1521 : : /* Regular tuple, standard table TID representation */
1522 [ + + ]: 2340678 : if (callback(&itup->t_tid, callback_state))
1523 : : {
1524 : 890620 : deletable[ndeletable++] = offnum;
1525 : 890620 : nhtidsdead++;
1526 : : }
1527 : : else
1528 : 1450058 : nhtidslive++;
1529 : : }
1530 : : else
1531 : : {
1532 : : BTVacuumPosting vacposting;
1533 : : int nremaining;
1534 : :
1535 : : /* Posting list tuple */
1536 : 83571 : vacposting = btreevacuumposting(vstate, itup, offnum,
1537 : : &nremaining);
1538 [ + + ]: 83571 : if (vacposting == NULL)
1539 : : {
1540 : : /*
1541 : : * All table TIDs from the posting tuple remain, so no
1542 : : * delete or update required
1543 : : */
1544 [ - + ]: 28755 : Assert(nremaining == BTreeTupleGetNPosting(itup));
1545 : : }
1546 [ + + ]: 54816 : else if (nremaining > 0)
1547 : : {
1548 : :
1549 : : /*
1550 : : * Store metadata about posting list tuple in
1551 : : * updatable array for entire page. Existing tuple
1552 : : * will be updated during the later call to
1553 : : * _bt_delitems_vacuum().
1554 : : */
1555 [ - + ]: 24641 : Assert(nremaining < BTreeTupleGetNPosting(itup));
1556 : 24641 : updatable[nupdatable++] = vacposting;
1557 : 24641 : nhtidsdead += BTreeTupleGetNPosting(itup) - nremaining;
1558 : : }
1559 : : else
1560 : : {
1561 : : /*
1562 : : * All table TIDs from the posting list must be
1563 : : * deleted. We'll delete the index tuple completely
1564 : : * (no update required).
1565 : : */
1566 [ - + ]: 30175 : Assert(nremaining == 0);
1567 : 30175 : deletable[ndeletable++] = offnum;
1568 : 30175 : nhtidsdead += BTreeTupleGetNPosting(itup);
1569 : 30175 : pfree(vacposting);
1570 : : }
1571 : :
1572 : 83571 : nhtidslive += nremaining;
1573 : : }
1574 : : }
1575 : : }
1576 : :
1577 : : /*
1578 : : * Apply any needed deletes or updates. We issue just one
1579 : : * _bt_delitems_vacuum() call per page, so as to minimize WAL traffic.
1580 : : */
1581 [ + + + + ]: 12628 : if (ndeletable > 0 || nupdatable > 0)
1582 : : {
1953 1583 [ - + ]: 7912 : Assert(nhtidsdead >= ndeletable + nupdatable);
2019 1584 : 7912 : _bt_delitems_vacuum(rel, buf, deletable, ndeletable, updatable,
1585 : : nupdatable);
1586 : :
1587 : 7912 : stats->tuples_removed += nhtidsdead;
1588 : : /* must recompute maxoff */
7061 tgl@sss.pgh.pa.us 1589 : 7912 : maxoff = PageGetMaxOffsetNumber(page);
1590 : :
1591 : : /* can't leak memory here */
2019 pg@bowt.ie 1592 [ + + ]: 32553 : for (int i = 0; i < nupdatable; i++)
1593 : 24641 : pfree(updatable[i]);
1594 : : }
1595 : : else
1596 : : {
1597 : : /*
1598 : : * If the leaf page has been split during this vacuum cycle, it
1599 : : * seems worth expending a write to clear btpo_cycleid even if we
1600 : : * don't have any deletions to do. (If we do, _bt_delitems_vacuum
1601 : : * takes care of this.) This ensures we won't process the page
1602 : : * again.
1603 : : *
1604 : : * We treat this like a hint-bit update because there's no need to
1605 : : * WAL-log it.
1606 : : */
1607 [ - + ]: 4716 : Assert(nhtidsdead == 0);
7061 tgl@sss.pgh.pa.us 1608 [ + + ]: 4716 : if (vstate->cycleid != 0 &&
1609 [ - + ]: 4638 : opaque->btpo_cycleid == vstate->cycleid)
1610 : : {
7061 tgl@sss.pgh.pa.us 1611 :UBC 0 : opaque->btpo_cycleid = 0;
4464 jdavis@postgresql.or 1612 : 0 : MarkBufferDirtyHint(buf, true);
1613 : : }
1614 : : }
1615 : :
1616 : : /*
1617 : : * If the leaf page is now empty, try to delete it; else count the
1618 : : * live tuples (live table TIDs in posting lists are counted as
1619 : : * separate live tuples). We don't delete when backtracking, though,
1620 : : * since that would require teaching _bt_pagedel() about backtracking
1621 : : * (doesn't seem worth adding more complexity to deal with that).
1622 : : *
1623 : : * We don't count the number of live TIDs during cleanup-only calls to
1624 : : * btvacuumscan (i.e. when callback is not set). We count the number
1625 : : * of index tuples directly instead. This avoids the expense of
1626 : : * directly examining all of the tuples on each page. VACUUM will
1627 : : * treat num_index_tuples as an estimate in cleanup-only case, so it
1628 : : * doesn't matter that this underestimates num_index_tuples
1629 : : * significantly in some cases.
1630 : : */
7061 tgl@sss.pgh.pa.us 1631 [ + + ]:CBC 12628 : if (minoff > maxoff)
1953 pg@bowt.ie 1632 : 3000 : attempt_pagedel = (blkno == scanblkno);
1767 1633 [ + + ]: 9628 : else if (callback)
2019 1634 : 9554 : stats->num_index_tuples += nhtidslive;
1635 : : else
1767 1636 : 74 : stats->num_index_tuples += maxoff - minoff + 1;
1637 : :
1953 1638 [ + + - + ]: 12628 : Assert(!attempt_pagedel || nhtidslive == 0);
1639 : : }
1640 : :
1641 [ + + ]: 15091 : if (attempt_pagedel)
1642 : : {
1643 : : MemoryContext oldcontext;
1644 : :
1645 : : /* Run pagedel in a temp context to avoid memory leakage */
7061 tgl@sss.pgh.pa.us 1646 : 3000 : MemoryContextReset(vstate->pagedelcontext);
1647 : 3000 : oldcontext = MemoryContextSwitchTo(vstate->pagedelcontext);
1648 : :
1649 : : /*
1650 : : * _bt_pagedel maintains the bulk delete stats on our behalf;
1651 : : * pages_newly_deleted and pages_deleted are likely to be incremented
1652 : : * during call
1653 : : */
1953 pg@bowt.ie 1654 [ - + ]: 3000 : Assert(blkno == scanblkno);
1654 1655 : 3000 : _bt_pagedel(rel, buf, vstate);
1656 : :
7061 tgl@sss.pgh.pa.us 1657 : 3000 : MemoryContextSwitchTo(oldcontext);
1658 : : /* pagedel released buffer, so we shouldn't */
1659 : : }
1660 : : else
1661 : 12091 : _bt_relbuf(rel, buf);
1662 : :
1953 pg@bowt.ie 1663 [ - + ]: 15091 : if (backtrack_to != P_NONE)
1664 : : {
1953 pg@bowt.ie 1665 :UBC 0 : blkno = backtrack_to;
1666 : :
1667 : : /* check for vacuum delay while not holding any buffer lock */
169 melanieplageman@gmai 1668 : 0 : vacuum_delay_point(false);
1669 : :
1670 : : /*
1671 : : * We can't use _bt_getbuf() here because it always applies
1672 : : * _bt_checkpage(), which will barf on an all-zero page. We want to
1673 : : * recycle all-zero pages, not fail. Also, we want to use a
1674 : : * nondefault buffer access strategy.
1675 : : */
1676 : 0 : buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL,
1677 : : info->strategy);
1953 pg@bowt.ie 1678 : 0 : goto backtrack;
1679 : : }
1680 : :
169 melanieplageman@gmai 1681 :CBC 15091 : return scanblkno;
1682 : : }
1683 : :
1684 : : /*
1685 : : * btreevacuumposting --- determine TIDs still needed in posting list
1686 : : *
1687 : : * Returns metadata describing how to build replacement tuple without the TIDs
1688 : : * that VACUUM needs to delete. Returned value is NULL in the common case
1689 : : * where no changes are needed to caller's posting list tuple (we avoid
1690 : : * allocating memory here as an optimization).
1691 : : *
1692 : : * The number of TIDs that should remain in the posting list tuple is set for
1693 : : * caller in *nremaining.
1694 : : */
1695 : : static BTVacuumPosting
2019 pg@bowt.ie 1696 : 83571 : btreevacuumposting(BTVacState *vstate, IndexTuple posting,
1697 : : OffsetNumber updatedoffset, int *nremaining)
1698 : : {
1699 : 83571 : int live = 0;
1700 : 83571 : int nitem = BTreeTupleGetNPosting(posting);
1701 : 83571 : ItemPointer items = BTreeTupleGetPosting(posting);
1702 : 83571 : BTVacuumPosting vacposting = NULL;
1703 : :
1704 [ + + ]: 454288 : for (int i = 0; i < nitem; i++)
1705 : : {
1706 [ + + ]: 370717 : if (!vstate->callback(items + i, vstate->callback_state))
1707 : : {
1708 : : /* Live table TID */
1709 : 191838 : live++;
1710 : : }
1711 [ + + ]: 178879 : else if (vacposting == NULL)
1712 : : {
1713 : : /*
1714 : : * First dead table TID encountered.
1715 : : *
1716 : : * It's now clear that we need to delete one or more dead table
1717 : : * TIDs, so start maintaining metadata describing how to update
1718 : : * existing posting list tuple.
1719 : : */
1720 : 54816 : vacposting = palloc(offsetof(BTVacuumPostingData, deletetids) +
1721 : : nitem * sizeof(uint16));
1722 : :
1723 : 54816 : vacposting->itup = posting;
1724 : 54816 : vacposting->updatedoffset = updatedoffset;
1725 : 54816 : vacposting->ndeletedtids = 0;
1726 : 54816 : vacposting->deletetids[vacposting->ndeletedtids++] = i;
1727 : : }
1728 : : else
1729 : : {
1730 : : /* Second or subsequent dead table TID */
1731 : 124063 : vacposting->deletetids[vacposting->ndeletedtids++] = i;
1732 : : }
1733 : : }
1734 : :
1735 : 83571 : *nremaining = live;
1736 : 83571 : return vacposting;
1737 : : }
1738 : :
1739 : : /*
1740 : : * btcanreturn() -- Check whether btree indexes support index-only scans.
1741 : : *
1742 : : * btrees always do, so this is trivial.
1743 : : */
1744 : : bool
3520 tgl@sss.pgh.pa.us 1745 : 545504 : btcanreturn(Relation index, int attno)
1746 : : {
1747 : 545504 : return true;
1748 : : }
1749 : :
1750 : : /*
1751 : : * btgettreeheight() -- Compute tree height for use by btcostestimate().
1752 : : */
1753 : : int
361 peter@eisentraut.org 1754 : 348433 : btgettreeheight(Relation rel)
1755 : : {
1756 : 348433 : return _bt_getrootheight(rel);
1757 : : }
1758 : :
1759 : : CompareType
197 peter@eisentraut.org 1760 :UBC 0 : bttranslatestrategy(StrategyNumber strategy, Oid opfamily)
1761 : : {
216 1762 [ # # # # : 0 : switch (strategy)
# # ]
1763 : : {
1764 : 0 : case BTLessStrategyNumber:
1765 : 0 : return COMPARE_LT;
1766 : 0 : case BTLessEqualStrategyNumber:
1767 : 0 : return COMPARE_LE;
1768 : 0 : case BTEqualStrategyNumber:
1769 : 0 : return COMPARE_EQ;
1770 : 0 : case BTGreaterEqualStrategyNumber:
1771 : 0 : return COMPARE_GE;
1772 : 0 : case BTGreaterStrategyNumber:
1773 : 0 : return COMPARE_GT;
1774 : 0 : default:
1775 : 0 : return COMPARE_INVALID;
1776 : : }
1777 : : }
1778 : :
1779 : : StrategyNumber
197 1780 : 0 : bttranslatecmptype(CompareType cmptype, Oid opfamily)
1781 : : {
216 1782 [ # # # # : 0 : switch (cmptype)
# # ]
1783 : : {
1784 : 0 : case COMPARE_LT:
1785 : 0 : return BTLessStrategyNumber;
1786 : 0 : case COMPARE_LE:
1787 : 0 : return BTLessEqualStrategyNumber;
1788 : 0 : case COMPARE_EQ:
1789 : 0 : return BTEqualStrategyNumber;
1790 : 0 : case COMPARE_GE:
1791 : 0 : return BTGreaterEqualStrategyNumber;
1792 : 0 : case COMPARE_GT:
1793 : 0 : return BTGreaterStrategyNumber;
1794 : 0 : default:
1795 : 0 : return InvalidStrategy;
1796 : : }
1797 : : }
|
