LCOV - code coverage report
Current view: top level - src/backend/access/index - indexam.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 203 207 98.1 %
Date: 2023-12-07 07:10:44 Functions: 26 26 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * indexam.c
       4             :  *    general index access method routines
       5             :  *
       6             :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/access/index/indexam.c
      12             :  *
      13             :  * INTERFACE ROUTINES
      14             :  *      index_open      - open an index relation by relation OID
      15             :  *      index_close     - close an index relation
      16             :  *      index_beginscan - start a scan of an index with amgettuple
      17             :  *      index_beginscan_bitmap - start a scan of an index with amgetbitmap
      18             :  *      index_rescan    - restart a scan of an index
      19             :  *      index_endscan   - end a scan
      20             :  *      index_insert    - insert an index tuple into a relation
      21             :  *      index_markpos   - mark a scan position
      22             :  *      index_restrpos  - restore a scan position
      23             :  *      index_parallelscan_estimate - estimate shared memory for parallel scan
      24             :  *      index_parallelscan_initialize - initialize parallel scan
      25             :  *      index_parallelrescan  - (re)start a parallel scan of an index
      26             :  *      index_beginscan_parallel - join parallel index scan
      27             :  *      index_getnext_tid   - get the next TID from a scan
      28             :  *      index_fetch_heap        - get the scan's next heap tuple
      29             :  *      index_getnext_slot  - get the next tuple from a scan
      30             :  *      index_getbitmap - get all tuples from a scan
      31             :  *      index_bulk_delete   - bulk deletion of index tuples
      32             :  *      index_vacuum_cleanup    - post-deletion cleanup of an index
      33             :  *      index_can_return    - does index support index-only scans?
      34             :  *      index_getprocid - get a support procedure OID
      35             :  *      index_getprocinfo - get a support procedure's lookup info
      36             :  *
      37             :  * NOTES
      38             :  *      This file contains the index_ routines which used
      39             :  *      to be a scattered collection of stuff in access/genam.
      40             :  *
      41             :  *-------------------------------------------------------------------------
      42             :  */
      43             : 
      44             : #include "postgres.h"
      45             : 
      46             : #include "access/amapi.h"
      47             : #include "access/heapam.h"
      48             : #include "access/reloptions.h"
      49             : #include "access/relscan.h"
      50             : #include "access/tableam.h"
      51             : #include "access/transam.h"
      52             : #include "access/xlog.h"
      53             : #include "catalog/index.h"
      54             : #include "catalog/pg_amproc.h"
      55             : #include "catalog/pg_type.h"
      56             : #include "commands/defrem.h"
      57             : #include "nodes/makefuncs.h"
      58             : #include "pgstat.h"
      59             : #include "storage/bufmgr.h"
      60             : #include "storage/lmgr.h"
      61             : #include "storage/predicate.h"
      62             : #include "utils/ruleutils.h"
      63             : #include "utils/snapmgr.h"
      64             : #include "utils/syscache.h"
      65             : 
      66             : 
      67             : /* ----------------------------------------------------------------
      68             :  *                  macros used in index_ routines
      69             :  *
      70             :  * Note: the ReindexIsProcessingIndex() check in RELATION_CHECKS is there
      71             :  * to check that we don't try to scan or do retail insertions into an index
      72             :  * that is currently being rebuilt or pending rebuild.  This helps to catch
      73             :  * things that don't work when reindexing system catalogs.  The assertion
      74             :  * doesn't prevent the actual rebuild because we don't use RELATION_CHECKS
      75             :  * when calling the index AM's ambuild routine, and there is no reason for
      76             :  * ambuild to call its subsidiary routines through this file.
      77             :  * ----------------------------------------------------------------
      78             :  */
      79             : #define RELATION_CHECKS \
      80             : ( \
      81             :     AssertMacro(RelationIsValid(indexRelation)), \
      82             :     AssertMacro(PointerIsValid(indexRelation->rd_indam)), \
      83             :     AssertMacro(!ReindexIsProcessingIndex(RelationGetRelid(indexRelation))) \
      84             : )
      85             : 
      86             : #define SCAN_CHECKS \
      87             : ( \
      88             :     AssertMacro(IndexScanIsValid(scan)), \
      89             :     AssertMacro(RelationIsValid(scan->indexRelation)), \
      90             :     AssertMacro(PointerIsValid(scan->indexRelation->rd_indam)) \
      91             : )
      92             : 
      93             : #define CHECK_REL_PROCEDURE(pname) \
      94             : do { \
      95             :     if (indexRelation->rd_indam->pname == NULL) \
      96             :         elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
      97             :              CppAsString(pname), RelationGetRelationName(indexRelation)); \
      98             : } while(0)
      99             : 
     100             : #define CHECK_SCAN_PROCEDURE(pname) \
     101             : do { \
     102             :     if (scan->indexRelation->rd_indam->pname == NULL) \
     103             :         elog(ERROR, "function \"%s\" is not defined for index \"%s\"", \
     104             :              CppAsString(pname), RelationGetRelationName(scan->indexRelation)); \
     105             : } while(0)
     106             : 
     107             : static IndexScanDesc index_beginscan_internal(Relation indexRelation,
     108             :                                               int nkeys, int norderbys, Snapshot snapshot,
     109             :                                               ParallelIndexScanDesc pscan, bool temp_snap);
     110             : 
     111             : 
     112             : /* ----------------------------------------------------------------
     113             :  *                 index_ interface functions
     114             :  * ----------------------------------------------------------------
     115             :  */
     116             : 
     117             : /* ----------------
     118             :  *      index_open - open an index relation by relation OID
     119             :  *
     120             :  *      If lockmode is not "NoLock", the specified kind of lock is
     121             :  *      obtained on the index.  (Generally, NoLock should only be
     122             :  *      used if the caller knows it has some appropriate lock on the
     123             :  *      index already.)
     124             :  *
     125             :  *      An error is raised if the index does not exist.
     126             :  *
     127             :  *      This is a convenience routine adapted for indexscan use.
     128             :  *      Some callers may prefer to use relation_open directly.
     129             :  * ----------------
     130             :  */
     131             : Relation
     132    13416336 : index_open(Oid relationId, LOCKMODE lockmode)
     133             : {
     134             :     Relation    r;
     135             : 
     136    13416336 :     r = relation_open(relationId, lockmode);
     137             : 
     138    13416320 :     if (r->rd_rel->relkind != RELKIND_INDEX &&
     139       11274 :         r->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
     140          30 :         ereport(ERROR,
     141             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
     142             :                  errmsg("\"%s\" is not an index",
     143             :                         RelationGetRelationName(r))));
     144             : 
     145    13416290 :     return r;
     146             : }
     147             : 
     148             : /* ----------------
     149             :  *      index_close - close an index relation
     150             :  *
     151             :  *      If lockmode is not "NoLock", we then release the specified lock.
     152             :  *
     153             :  *      Note that it is often sensible to hold a lock beyond index_close;
     154             :  *      in that case, the lock is released automatically at xact end.
     155             :  * ----------------
     156             :  */
     157             : void
     158    13443682 : index_close(Relation relation, LOCKMODE lockmode)
     159             : {
     160    13443682 :     LockRelId   relid = relation->rd_lockInfo.lockRelId;
     161             : 
     162             :     Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
     163             : 
     164             :     /* The relcache does the real work... */
     165    13443682 :     RelationClose(relation);
     166             : 
     167    13443682 :     if (lockmode != NoLock)
     168    12277060 :         UnlockRelationId(&relid, lockmode);
     169    13443682 : }
     170             : 
     171             : /* ----------------
     172             :  *      index_insert - insert an index tuple into a relation
     173             :  * ----------------
     174             :  */
     175             : bool
     176     7234044 : index_insert(Relation indexRelation,
     177             :              Datum *values,
     178             :              bool *isnull,
     179             :              ItemPointer heap_t_ctid,
     180             :              Relation heapRelation,
     181             :              IndexUniqueCheck checkUnique,
     182             :              bool indexUnchanged,
     183             :              IndexInfo *indexInfo)
     184             : {
     185             :     RELATION_CHECKS;
     186     7234044 :     CHECK_REL_PROCEDURE(aminsert);
     187             : 
     188     7234044 :     if (!(indexRelation->rd_indam->ampredlocks))
     189      576710 :         CheckForSerializableConflictIn(indexRelation,
     190             :                                        (ItemPointer) NULL,
     191             :                                        InvalidBlockNumber);
     192             : 
     193     7234044 :     return indexRelation->rd_indam->aminsert(indexRelation, values, isnull,
     194             :                                              heap_t_ctid, heapRelation,
     195             :                                              checkUnique, indexUnchanged,
     196             :                                              indexInfo);
     197             : }
     198             : 
     199             : /* -------------------------
     200             :  *      index_insert_cleanup - clean up after all index inserts are done
     201             :  * -------------------------
     202             :  */
     203             : void
     204     2591944 : index_insert_cleanup(Relation indexRelation,
     205             :                      IndexInfo *indexInfo)
     206             : {
     207             :     RELATION_CHECKS;
     208             :     Assert(indexInfo);
     209             : 
     210     2591944 :     if (indexRelation->rd_indam->aminsertcleanup && indexInfo->ii_AmCache)
     211        1084 :         indexRelation->rd_indam->aminsertcleanup(indexInfo);
     212     2591944 : }
     213             : 
     214             : /*
     215             :  * index_beginscan - start a scan of an index with amgettuple
     216             :  *
     217             :  * Caller must be holding suitable locks on the heap and the index.
     218             :  */
     219             : IndexScanDesc
     220     9902772 : index_beginscan(Relation heapRelation,
     221             :                 Relation indexRelation,
     222             :                 Snapshot snapshot,
     223             :                 int nkeys, int norderbys)
     224             : {
     225             :     IndexScanDesc scan;
     226             : 
     227             :     Assert(snapshot != InvalidSnapshot);
     228             : 
     229     9902772 :     scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);
     230             : 
     231             :     /*
     232             :      * Save additional parameters into the scandesc.  Everything else was set
     233             :      * up by RelationGetIndexScan.
     234             :      */
     235     9902772 :     scan->heapRelation = heapRelation;
     236     9902772 :     scan->xs_snapshot = snapshot;
     237             : 
     238             :     /* prepare to fetch index matches from table */
     239     9902772 :     scan->xs_heapfetch = table_index_fetch_begin(heapRelation);
     240             : 
     241     9902772 :     return scan;
     242             : }
     243             : 
     244             : /*
     245             :  * index_beginscan_bitmap - start a scan of an index with amgetbitmap
     246             :  *
     247             :  * As above, caller had better be holding some lock on the parent heap
     248             :  * relation, even though it's not explicitly mentioned here.
     249             :  */
     250             : IndexScanDesc
     251       14182 : index_beginscan_bitmap(Relation indexRelation,
     252             :                        Snapshot snapshot,
     253             :                        int nkeys)
     254             : {
     255             :     IndexScanDesc scan;
     256             : 
     257             :     Assert(snapshot != InvalidSnapshot);
     258             : 
     259       14182 :     scan = index_beginscan_internal(indexRelation, nkeys, 0, snapshot, NULL, false);
     260             : 
     261             :     /*
     262             :      * Save additional parameters into the scandesc.  Everything else was set
     263             :      * up by RelationGetIndexScan.
     264             :      */
     265       14182 :     scan->xs_snapshot = snapshot;
     266             : 
     267       14182 :     return scan;
     268             : }
     269             : 
     270             : /*
     271             :  * index_beginscan_internal --- common code for index_beginscan variants
     272             :  */
     273             : static IndexScanDesc
     274     9917302 : index_beginscan_internal(Relation indexRelation,
     275             :                          int nkeys, int norderbys, Snapshot snapshot,
     276             :                          ParallelIndexScanDesc pscan, bool temp_snap)
     277             : {
     278             :     IndexScanDesc scan;
     279             : 
     280             :     RELATION_CHECKS;
     281     9917302 :     CHECK_REL_PROCEDURE(ambeginscan);
     282             : 
     283     9917302 :     if (!(indexRelation->rd_indam->ampredlocks))
     284        4624 :         PredicateLockRelation(indexRelation, snapshot);
     285             : 
     286             :     /*
     287             :      * We hold a reference count to the relcache entry throughout the scan.
     288             :      */
     289     9917302 :     RelationIncrementReferenceCount(indexRelation);
     290             : 
     291             :     /*
     292             :      * Tell the AM to open a scan.
     293             :      */
     294     9917302 :     scan = indexRelation->rd_indam->ambeginscan(indexRelation, nkeys,
     295             :                                                 norderbys);
     296             :     /* Initialize information for parallel scan. */
     297     9917302 :     scan->parallel_scan = pscan;
     298     9917302 :     scan->xs_temp_snap = temp_snap;
     299             : 
     300     9917302 :     return scan;
     301             : }
     302             : 
     303             : /* ----------------
     304             :  *      index_rescan  - (re)start a scan of an index
     305             :  *
     306             :  * During a restart, the caller may specify a new set of scankeys and/or
     307             :  * orderbykeys; but the number of keys cannot differ from what index_beginscan
     308             :  * was told.  (Later we might relax that to "must not exceed", but currently
     309             :  * the index AMs tend to assume that scan->numberOfKeys is what to believe.)
     310             :  * To restart the scan without changing keys, pass NULL for the key arrays.
     311             :  * (Of course, keys *must* be passed on the first call, unless
     312             :  * scan->numberOfKeys is zero.)
     313             :  * ----------------
     314             :  */
     315             : void
     316    10327240 : index_rescan(IndexScanDesc scan,
     317             :              ScanKey keys, int nkeys,
     318             :              ScanKey orderbys, int norderbys)
     319             : {
     320             :     SCAN_CHECKS;
     321    10327240 :     CHECK_SCAN_PROCEDURE(amrescan);
     322             : 
     323             :     Assert(nkeys == scan->numberOfKeys);
     324             :     Assert(norderbys == scan->numberOfOrderBys);
     325             : 
     326             :     /* Release resources (like buffer pins) from table accesses */
     327    10327240 :     if (scan->xs_heapfetch)
     328    10309408 :         table_index_fetch_reset(scan->xs_heapfetch);
     329             : 
     330    10327240 :     scan->kill_prior_tuple = false; /* for safety */
     331    10327240 :     scan->xs_heap_continue = false;
     332             : 
     333    10327240 :     scan->indexRelation->rd_indam->amrescan(scan, keys, nkeys,
     334             :                                             orderbys, norderbys);
     335    10327240 : }
     336             : 
     337             : /* ----------------
     338             :  *      index_endscan - end a scan
     339             :  * ----------------
     340             :  */
     341             : void
     342     9915816 : index_endscan(IndexScanDesc scan)
     343             : {
     344             :     SCAN_CHECKS;
     345     9915816 :     CHECK_SCAN_PROCEDURE(amendscan);
     346             : 
     347             :     /* Release resources (like buffer pins) from table accesses */
     348     9915816 :     if (scan->xs_heapfetch)
     349             :     {
     350     9901700 :         table_index_fetch_end(scan->xs_heapfetch);
     351     9901700 :         scan->xs_heapfetch = NULL;
     352             :     }
     353             : 
     354             :     /* End the AM's scan */
     355     9915816 :     scan->indexRelation->rd_indam->amendscan(scan);
     356             : 
     357             :     /* Release index refcount acquired by index_beginscan */
     358     9915816 :     RelationDecrementReferenceCount(scan->indexRelation);
     359             : 
     360     9915816 :     if (scan->xs_temp_snap)
     361         348 :         UnregisterSnapshot(scan->xs_snapshot);
     362             : 
     363             :     /* Release the scan data structure itself */
     364     9915816 :     IndexScanEnd(scan);
     365     9915816 : }
     366             : 
     367             : /* ----------------
     368             :  *      index_markpos  - mark a scan position
     369             :  * ----------------
     370             :  */
     371             : void
     372      130042 : index_markpos(IndexScanDesc scan)
     373             : {
     374             :     SCAN_CHECKS;
     375      130042 :     CHECK_SCAN_PROCEDURE(ammarkpos);
     376             : 
     377      130042 :     scan->indexRelation->rd_indam->ammarkpos(scan);
     378      130042 : }
     379             : 
     380             : /* ----------------
     381             :  *      index_restrpos  - restore a scan position
     382             :  *
     383             :  * NOTE: this only restores the internal scan state of the index AM.  See
     384             :  * comments for ExecRestrPos().
     385             :  *
     386             :  * NOTE: For heap, in the presence of HOT chains, mark/restore only works
     387             :  * correctly if the scan's snapshot is MVCC-safe; that ensures that there's at
     388             :  * most one returnable tuple in each HOT chain, and so restoring the prior
     389             :  * state at the granularity of the index AM is sufficient.  Since the only
     390             :  * current user of mark/restore functionality is nodeMergejoin.c, this
     391             :  * effectively means that merge-join plans only work for MVCC snapshots.  This
     392             :  * could be fixed if necessary, but for now it seems unimportant.
     393             :  * ----------------
     394             :  */
     395             : void
     396       54018 : index_restrpos(IndexScanDesc scan)
     397             : {
     398             :     Assert(IsMVCCSnapshot(scan->xs_snapshot));
     399             : 
     400             :     SCAN_CHECKS;
     401       54018 :     CHECK_SCAN_PROCEDURE(amrestrpos);
     402             : 
     403             :     /* release resources (like buffer pins) from table accesses */
     404       54018 :     if (scan->xs_heapfetch)
     405       54018 :         table_index_fetch_reset(scan->xs_heapfetch);
     406             : 
     407       54018 :     scan->kill_prior_tuple = false; /* for safety */
     408       54018 :     scan->xs_heap_continue = false;
     409             : 
     410       54018 :     scan->indexRelation->rd_indam->amrestrpos(scan);
     411       54018 : }
     412             : 
     413             : /*
     414             :  * index_parallelscan_estimate - estimate shared memory for parallel scan
     415             :  *
     416             :  * Currently, we don't pass any information to the AM-specific estimator,
     417             :  * so it can probably only return a constant.  In the future, we might need
     418             :  * to pass more information.
     419             :  */
     420             : Size
     421          52 : index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
     422             : {
     423             :     Size        nbytes;
     424             : 
     425             :     Assert(snapshot != InvalidSnapshot);
     426             : 
     427             :     RELATION_CHECKS;
     428             : 
     429          52 :     nbytes = offsetof(ParallelIndexScanDescData, ps_snapshot_data);
     430          52 :     nbytes = add_size(nbytes, EstimateSnapshotSpace(snapshot));
     431          52 :     nbytes = MAXALIGN(nbytes);
     432             : 
     433             :     /*
     434             :      * If amestimateparallelscan is not provided, assume there is no
     435             :      * AM-specific data needed.  (It's hard to believe that could work, but
     436             :      * it's easy enough to cater to it here.)
     437             :      */
     438          52 :     if (indexRelation->rd_indam->amestimateparallelscan != NULL)
     439          52 :         nbytes = add_size(nbytes,
     440          52 :                           indexRelation->rd_indam->amestimateparallelscan());
     441             : 
     442          52 :     return nbytes;
     443             : }
     444             : 
     445             : /*
     446             :  * index_parallelscan_initialize - initialize parallel scan
     447             :  *
     448             :  * We initialize both the ParallelIndexScanDesc proper and the AM-specific
     449             :  * information which follows it.
     450             :  *
     451             :  * This function calls access method specific initialization routine to
     452             :  * initialize am specific information.  Call this just once in the leader
     453             :  * process; then, individual workers attach via index_beginscan_parallel.
     454             :  */
     455             : void
     456          52 : index_parallelscan_initialize(Relation heapRelation, Relation indexRelation,
     457             :                               Snapshot snapshot, ParallelIndexScanDesc target)
     458             : {
     459             :     Size        offset;
     460             : 
     461             :     Assert(snapshot != InvalidSnapshot);
     462             : 
     463             :     RELATION_CHECKS;
     464             : 
     465          52 :     offset = add_size(offsetof(ParallelIndexScanDescData, ps_snapshot_data),
     466             :                       EstimateSnapshotSpace(snapshot));
     467          52 :     offset = MAXALIGN(offset);
     468             : 
     469          52 :     target->ps_relid = RelationGetRelid(heapRelation);
     470          52 :     target->ps_indexid = RelationGetRelid(indexRelation);
     471          52 :     target->ps_offset = offset;
     472          52 :     SerializeSnapshot(snapshot, target->ps_snapshot_data);
     473             : 
     474             :     /* aminitparallelscan is optional; assume no-op if not provided by AM */
     475          52 :     if (indexRelation->rd_indam->aminitparallelscan != NULL)
     476             :     {
     477             :         void       *amtarget;
     478             : 
     479          52 :         amtarget = OffsetToPointer(target, offset);
     480          52 :         indexRelation->rd_indam->aminitparallelscan(amtarget);
     481             :     }
     482          52 : }
     483             : 
     484             : /* ----------------
     485             :  *      index_parallelrescan  - (re)start a parallel scan of an index
     486             :  * ----------------
     487             :  */
     488             : void
     489          24 : index_parallelrescan(IndexScanDesc scan)
     490             : {
     491             :     SCAN_CHECKS;
     492             : 
     493          24 :     if (scan->xs_heapfetch)
     494          24 :         table_index_fetch_reset(scan->xs_heapfetch);
     495             : 
     496             :     /* amparallelrescan is optional; assume no-op if not provided by AM */
     497          24 :     if (scan->indexRelation->rd_indam->amparallelrescan != NULL)
     498          24 :         scan->indexRelation->rd_indam->amparallelrescan(scan);
     499          24 : }
     500             : 
     501             : /*
     502             :  * index_beginscan_parallel - join parallel index scan
     503             :  *
     504             :  * Caller must be holding suitable locks on the heap and the index.
     505             :  */
     506             : IndexScanDesc
     507         348 : index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys,
     508             :                          int norderbys, ParallelIndexScanDesc pscan)
     509             : {
     510             :     Snapshot    snapshot;
     511             :     IndexScanDesc scan;
     512             : 
     513             :     Assert(RelationGetRelid(heaprel) == pscan->ps_relid);
     514         348 :     snapshot = RestoreSnapshot(pscan->ps_snapshot_data);
     515         348 :     RegisterSnapshot(snapshot);
     516         348 :     scan = index_beginscan_internal(indexrel, nkeys, norderbys, snapshot,
     517             :                                     pscan, true);
     518             : 
     519             :     /*
     520             :      * Save additional parameters into the scandesc.  Everything else was set
     521             :      * up by index_beginscan_internal.
     522             :      */
     523         348 :     scan->heapRelation = heaprel;
     524         348 :     scan->xs_snapshot = snapshot;
     525             : 
     526             :     /* prepare to fetch index matches from table */
     527         348 :     scan->xs_heapfetch = table_index_fetch_begin(heaprel);
     528             : 
     529         348 :     return scan;
     530             : }
     531             : 
     532             : /* ----------------
     533             :  * index_getnext_tid - get the next TID from a scan
     534             :  *
     535             :  * The result is the next TID satisfying the scan keys,
     536             :  * or NULL if no more matching tuples exist.
     537             :  * ----------------
     538             :  */
     539             : ItemPointer
     540    26308756 : index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
     541             : {
     542             :     bool        found;
     543             : 
     544             :     SCAN_CHECKS;
     545    26308756 :     CHECK_SCAN_PROCEDURE(amgettuple);
     546             : 
     547             :     /* XXX: we should assert that a snapshot is pushed or registered */
     548             :     Assert(TransactionIdIsValid(RecentXmin));
     549             : 
     550             :     /*
     551             :      * The AM's amgettuple proc finds the next index entry matching the scan
     552             :      * keys, and puts the TID into scan->xs_heaptid.  It should also set
     553             :      * scan->xs_recheck and possibly scan->xs_itup/scan->xs_hitup, though we
     554             :      * pay no attention to those fields here.
     555             :      */
     556    26308756 :     found = scan->indexRelation->rd_indam->amgettuple(scan, direction);
     557             : 
     558             :     /* Reset kill flag immediately for safety */
     559    26308752 :     scan->kill_prior_tuple = false;
     560    26308752 :     scan->xs_heap_continue = false;
     561             : 
     562             :     /* If we're out of index entries, we're done */
     563    26308752 :     if (!found)
     564             :     {
     565             :         /* release resources (like buffer pins) from table accesses */
     566     5049624 :         if (scan->xs_heapfetch)
     567     5049624 :             table_index_fetch_reset(scan->xs_heapfetch);
     568             : 
     569     5049624 :         return NULL;
     570             :     }
     571             :     Assert(ItemPointerIsValid(&scan->xs_heaptid));
     572             : 
     573    21259128 :     pgstat_count_index_tuples(scan->indexRelation, 1);
     574             : 
     575             :     /* Return the TID of the tuple we found. */
     576    21259128 :     return &scan->xs_heaptid;
     577             : }
     578             : 
     579             : /* ----------------
     580             :  *      index_fetch_heap - get the scan's next heap tuple
     581             :  *
     582             :  * The result is a visible heap tuple associated with the index TID most
     583             :  * recently fetched by index_getnext_tid, or NULL if no more matching tuples
     584             :  * exist.  (There can be more than one matching tuple because of HOT chains,
     585             :  * although when using an MVCC snapshot it should be impossible for more than
     586             :  * one such tuple to exist.)
     587             :  *
     588             :  * On success, the buffer containing the heap tup is pinned (the pin will be
     589             :  * dropped in a future index_getnext_tid, index_fetch_heap or index_endscan
     590             :  * call).
     591             :  *
     592             :  * Note: caller must check scan->xs_recheck, and perform rechecking of the
     593             :  * scan keys if required.  We do not do that here because we don't have
     594             :  * enough information to do it efficiently in the general case.
     595             :  * ----------------
     596             :  */
     597             : bool
     598    18027232 : index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot)
     599             : {
     600    18027232 :     bool        all_dead = false;
     601             :     bool        found;
     602             : 
     603    18027232 :     found = table_index_fetch_tuple(scan->xs_heapfetch, &scan->xs_heaptid,
     604             :                                     scan->xs_snapshot, slot,
     605             :                                     &scan->xs_heap_continue, &all_dead);
     606             : 
     607    18027222 :     if (found)
     608    17134586 :         pgstat_count_heap_fetch(scan->indexRelation);
     609             : 
     610             :     /*
     611             :      * If we scanned a whole HOT chain and found only dead tuples, tell index
     612             :      * AM to kill its entry for that TID (this will take effect in the next
     613             :      * amgettuple call, in index_getnext_tid).  We do not do this when in
     614             :      * recovery because it may violate MVCC to do so.  See comments in
     615             :      * RelationGetIndexScan().
     616             :      */
     617    18027222 :     if (!scan->xactStartedInRecovery)
     618    17745022 :         scan->kill_prior_tuple = all_dead;
     619             : 
     620    18027222 :     return found;
     621             : }
     622             : 
     623             : /* ----------------
     624             :  *      index_getnext_slot - get the next tuple from a scan
     625             :  *
     626             :  * The result is true if a tuple satisfying the scan keys and the snapshot was
     627             :  * found, false otherwise.  The tuple is stored in the specified slot.
     628             :  *
     629             :  * On success, resources (like buffer pins) are likely to be held, and will be
     630             :  * dropped by a future index_getnext_tid, index_fetch_heap or index_endscan
     631             :  * call).
     632             :  *
     633             :  * Note: caller must check scan->xs_recheck, and perform rechecking of the
     634             :  * scan keys if required.  We do not do that here because we don't have
     635             :  * enough information to do it efficiently in the general case.
     636             :  * ----------------
     637             :  */
     638             : bool
     639    21072028 : index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
     640             : {
     641             :     for (;;)
     642             :     {
     643    21072028 :         if (!scan->xs_heap_continue)
     644             :         {
     645             :             ItemPointer tid;
     646             : 
     647             :             /* Time to fetch the next TID from the index */
     648    20935178 :             tid = index_getnext_tid(scan, direction);
     649             : 
     650             :             /* If we're out of index entries, we're done */
     651    20935174 :             if (tid == NULL)
     652     4969454 :                 break;
     653             : 
     654             :             Assert(ItemPointerEquals(tid, &scan->xs_heaptid));
     655             :         }
     656             : 
     657             :         /*
     658             :          * Fetch the next (or only) visible heap tuple for this index entry.
     659             :          * If we don't find anything, loop around and grab the next TID from
     660             :          * the index.
     661             :          */
     662             :         Assert(ItemPointerIsValid(&scan->xs_heaptid));
     663    16102570 :         if (index_fetch_heap(scan, slot))
     664    15328806 :             return true;
     665             :     }
     666             : 
     667     4969454 :     return false;
     668             : }
     669             : 
     670             : /* ----------------
     671             :  *      index_getbitmap - get all tuples at once from an index scan
     672             :  *
     673             :  * Adds the TIDs of all heap tuples satisfying the scan keys to a bitmap.
     674             :  * Since there's no interlock between the index scan and the eventual heap
     675             :  * access, this is only safe to use with MVCC-based snapshots: the heap
     676             :  * item slot could have been replaced by a newer tuple by the time we get
     677             :  * to it.
     678             :  *
     679             :  * Returns the number of matching tuples found.  (Note: this might be only
     680             :  * approximate, so it should only be used for statistical purposes.)
     681             :  * ----------------
     682             :  */
     683             : int64
     684       17020 : index_getbitmap(IndexScanDesc scan, TIDBitmap *bitmap)
     685             : {
     686             :     int64       ntids;
     687             : 
     688             :     SCAN_CHECKS;
     689       17020 :     CHECK_SCAN_PROCEDURE(amgetbitmap);
     690             : 
     691             :     /* just make sure this is false... */
     692       17020 :     scan->kill_prior_tuple = false;
     693             : 
     694             :     /*
     695             :      * have the am's getbitmap proc do all the work.
     696             :      */
     697       17020 :     ntids = scan->indexRelation->rd_indam->amgetbitmap(scan, bitmap);
     698             : 
     699       17020 :     pgstat_count_index_tuples(scan->indexRelation, ntids);
     700             : 
     701       17020 :     return ntids;
     702             : }
     703             : 
     704             : /* ----------------
     705             :  *      index_bulk_delete - do mass deletion of index entries
     706             :  *
     707             :  *      callback routine tells whether a given main-heap tuple is
     708             :  *      to be deleted
     709             :  *
     710             :  *      return value is an optional palloc'd struct of statistics
     711             :  * ----------------
     712             :  */
     713             : IndexBulkDeleteResult *
     714        2178 : index_bulk_delete(IndexVacuumInfo *info,
     715             :                   IndexBulkDeleteResult *istat,
     716             :                   IndexBulkDeleteCallback callback,
     717             :                   void *callback_state)
     718             : {
     719        2178 :     Relation    indexRelation = info->index;
     720             : 
     721             :     RELATION_CHECKS;
     722        2178 :     CHECK_REL_PROCEDURE(ambulkdelete);
     723             : 
     724        2178 :     return indexRelation->rd_indam->ambulkdelete(info, istat,
     725             :                                                  callback, callback_state);
     726             : }
     727             : 
     728             : /* ----------------
     729             :  *      index_vacuum_cleanup - do post-deletion cleanup of an index
     730             :  *
     731             :  *      return value is an optional palloc'd struct of statistics
     732             :  * ----------------
     733             :  */
     734             : IndexBulkDeleteResult *
     735       34516 : index_vacuum_cleanup(IndexVacuumInfo *info,
     736             :                      IndexBulkDeleteResult *istat)
     737             : {
     738       34516 :     Relation    indexRelation = info->index;
     739             : 
     740             :     RELATION_CHECKS;
     741       34516 :     CHECK_REL_PROCEDURE(amvacuumcleanup);
     742             : 
     743       34516 :     return indexRelation->rd_indam->amvacuumcleanup(info, istat);
     744             : }
     745             : 
     746             : /* ----------------
     747             :  *      index_can_return
     748             :  *
     749             :  *      Does the index access method support index-only scans for the given
     750             :  *      column?
     751             :  * ----------------
     752             :  */
     753             : bool
     754     1131680 : index_can_return(Relation indexRelation, int attno)
     755             : {
     756             :     RELATION_CHECKS;
     757             : 
     758             :     /* amcanreturn is optional; assume false if not provided by AM */
     759     1131680 :     if (indexRelation->rd_indam->amcanreturn == NULL)
     760      272772 :         return false;
     761             : 
     762      858908 :     return indexRelation->rd_indam->amcanreturn(indexRelation, attno);
     763             : }
     764             : 
     765             : /* ----------------
     766             :  *      index_getprocid
     767             :  *
     768             :  *      Index access methods typically require support routines that are
     769             :  *      not directly the implementation of any WHERE-clause query operator
     770             :  *      and so cannot be kept in pg_amop.  Instead, such routines are kept
     771             :  *      in pg_amproc.  These registered procedure OIDs are assigned numbers
     772             :  *      according to a convention established by the access method.
     773             :  *      The general index code doesn't know anything about the routines
     774             :  *      involved; it just builds an ordered list of them for
     775             :  *      each attribute on which an index is defined.
     776             :  *
     777             :  *      As of Postgres 8.3, support routines within an operator family
     778             :  *      are further subdivided by the "left type" and "right type" of the
     779             :  *      query operator(s) that they support.  The "default" functions for a
     780             :  *      particular indexed attribute are those with both types equal to
     781             :  *      the index opclass' opcintype (note that this is subtly different
     782             :  *      from the indexed attribute's own type: it may be a binary-compatible
     783             :  *      type instead).  Only the default functions are stored in relcache
     784             :  *      entries --- access methods can use the syscache to look up non-default
     785             :  *      functions.
     786             :  *
     787             :  *      This routine returns the requested default procedure OID for a
     788             :  *      particular indexed attribute.
     789             :  * ----------------
     790             :  */
     791             : RegProcedure
     792     1466894 : index_getprocid(Relation irel,
     793             :                 AttrNumber attnum,
     794             :                 uint16 procnum)
     795             : {
     796             :     RegProcedure *loc;
     797             :     int         nproc;
     798             :     int         procindex;
     799             : 
     800     1466894 :     nproc = irel->rd_indam->amsupport;
     801             : 
     802             :     Assert(procnum > 0 && procnum <= (uint16) nproc);
     803             : 
     804     1466894 :     procindex = (nproc * (attnum - 1)) + (procnum - 1);
     805             : 
     806     1466894 :     loc = irel->rd_support;
     807             : 
     808             :     Assert(loc != NULL);
     809             : 
     810     1466894 :     return loc[procindex];
     811             : }
     812             : 
     813             : /* ----------------
     814             :  *      index_getprocinfo
     815             :  *
     816             :  *      This routine allows index AMs to keep fmgr lookup info for
     817             :  *      support procs in the relcache.  As above, only the "default"
     818             :  *      functions for any particular indexed attribute are cached.
     819             :  *
     820             :  * Note: the return value points into cached data that will be lost during
     821             :  * any relcache rebuild!  Therefore, either use the callinfo right away,
     822             :  * or save it only after having acquired some type of lock on the index rel.
     823             :  * ----------------
     824             :  */
     825             : FmgrInfo *
     826    36924500 : index_getprocinfo(Relation irel,
     827             :                   AttrNumber attnum,
     828             :                   uint16 procnum)
     829             : {
     830             :     FmgrInfo   *locinfo;
     831             :     int         nproc;
     832             :     int         optsproc;
     833             :     int         procindex;
     834             : 
     835    36924500 :     nproc = irel->rd_indam->amsupport;
     836    36924500 :     optsproc = irel->rd_indam->amoptsprocnum;
     837             : 
     838             :     Assert(procnum > 0 && procnum <= (uint16) nproc);
     839             : 
     840    36924500 :     procindex = (nproc * (attnum - 1)) + (procnum - 1);
     841             : 
     842    36924500 :     locinfo = irel->rd_supportinfo;
     843             : 
     844             :     Assert(locinfo != NULL);
     845             : 
     846    36924500 :     locinfo += procindex;
     847             : 
     848             :     /* Initialize the lookup info if first time through */
     849    36924500 :     if (locinfo->fn_oid == InvalidOid)
     850             :     {
     851      864064 :         RegProcedure *loc = irel->rd_support;
     852             :         RegProcedure procId;
     853             : 
     854             :         Assert(loc != NULL);
     855             : 
     856      864064 :         procId = loc[procindex];
     857             : 
     858             :         /*
     859             :          * Complain if function was not found during IndexSupportInitialize.
     860             :          * This should not happen unless the system tables contain bogus
     861             :          * entries for the index opclass.  (If an AM wants to allow a support
     862             :          * function to be optional, it can use index_getprocid.)
     863             :          */
     864      864064 :         if (!RegProcedureIsValid(procId))
     865           0 :             elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
     866             :                  procnum, attnum, RelationGetRelationName(irel));
     867             : 
     868      864064 :         fmgr_info_cxt(procId, locinfo, irel->rd_indexcxt);
     869             : 
     870      864064 :         if (procnum != optsproc)
     871             :         {
     872             :             /* Initialize locinfo->fn_expr with opclass options Const */
     873      862298 :             bytea     **attoptions = RelationGetIndexAttOptions(irel, false);
     874      862298 :             MemoryContext oldcxt = MemoryContextSwitchTo(irel->rd_indexcxt);
     875             : 
     876      862298 :             set_fn_opclass_options(locinfo, attoptions[attnum - 1]);
     877             : 
     878      862298 :             MemoryContextSwitchTo(oldcxt);
     879             :         }
     880             :     }
     881             : 
     882    36924500 :     return locinfo;
     883             : }
     884             : 
     885             : /* ----------------
     886             :  *      index_store_float8_orderby_distances
     887             :  *
     888             :  *      Convert AM distance function's results (that can be inexact)
     889             :  *      to ORDER BY types and save them into xs_orderbyvals/xs_orderbynulls
     890             :  *      for a possible recheck.
     891             :  * ----------------
     892             :  */
     893             : void
     894      364600 : index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
     895             :                                      IndexOrderByDistance *distances,
     896             :                                      bool recheckOrderBy)
     897             : {
     898             :     int         i;
     899             : 
     900             :     Assert(distances || !recheckOrderBy);
     901             : 
     902      364600 :     scan->xs_recheckorderby = recheckOrderBy;
     903             : 
     904      729218 :     for (i = 0; i < scan->numberOfOrderBys; i++)
     905             :     {
     906      364618 :         if (orderByTypes[i] == FLOAT8OID)
     907             :         {
     908             : #ifndef USE_FLOAT8_BYVAL
     909             :             /* must free any old value to avoid memory leakage */
     910             :             if (!scan->xs_orderbynulls[i])
     911             :                 pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
     912             : #endif
     913      364488 :             if (distances && !distances[i].isnull)
     914             :             {
     915      364428 :                 scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
     916      364428 :                 scan->xs_orderbynulls[i] = false;
     917             :             }
     918             :             else
     919             :             {
     920          60 :                 scan->xs_orderbyvals[i] = (Datum) 0;
     921          60 :                 scan->xs_orderbynulls[i] = true;
     922             :             }
     923             :         }
     924         130 :         else if (orderByTypes[i] == FLOAT4OID)
     925             :         {
     926             :             /* convert distance function's result to ORDER BY type */
     927          70 :             if (distances && !distances[i].isnull)
     928             :             {
     929          70 :                 scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
     930          70 :                 scan->xs_orderbynulls[i] = false;
     931             :             }
     932             :             else
     933             :             {
     934           0 :                 scan->xs_orderbyvals[i] = (Datum) 0;
     935           0 :                 scan->xs_orderbynulls[i] = true;
     936             :             }
     937             :         }
     938             :         else
     939             :         {
     940             :             /*
     941             :              * If the ordering operator's return value is anything else, we
     942             :              * don't know how to convert the float8 bound calculated by the
     943             :              * distance function to that.  The executor won't actually need
     944             :              * the order by values we return here, if there are no lossy
     945             :              * results, so only insist on converting if the *recheck flag is
     946             :              * set.
     947             :              */
     948          60 :             if (scan->xs_recheckorderby)
     949           0 :                 elog(ERROR, "ORDER BY operator must return float8 or float4 if the distance function is lossy");
     950          60 :             scan->xs_orderbynulls[i] = true;
     951             :         }
     952             :     }
     953      364600 : }
     954             : 
     955             : /* ----------------
     956             :  *      index_opclass_options
     957             :  *
     958             :  *      Parse opclass-specific options for index column.
     959             :  * ----------------
     960             :  */
     961             : bytea *
     962      627540 : index_opclass_options(Relation indrel, AttrNumber attnum, Datum attoptions,
     963             :                       bool validate)
     964             : {
     965      627540 :     int         amoptsprocnum = indrel->rd_indam->amoptsprocnum;
     966      627540 :     Oid         procid = InvalidOid;
     967             :     FmgrInfo   *procinfo;
     968             :     local_relopts relopts;
     969             : 
     970             :     /* fetch options support procedure if specified */
     971      627540 :     if (amoptsprocnum != 0)
     972      627480 :         procid = index_getprocid(indrel, attnum, amoptsprocnum);
     973             : 
     974      627540 :     if (!OidIsValid(procid))
     975             :     {
     976             :         Oid         opclass;
     977             :         Datum       indclassDatum;
     978             :         oidvector  *indclass;
     979             : 
     980      625056 :         if (!DatumGetPointer(attoptions))
     981      625050 :             return NULL;        /* ok, no options, no procedure */
     982             : 
     983             :         /*
     984             :          * Report an error if the opclass's options-parsing procedure does not
     985             :          * exist but the opclass options are specified.
     986             :          */
     987           6 :         indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indrel->rd_indextuple,
     988             :                                                Anum_pg_index_indclass);
     989           6 :         indclass = (oidvector *) DatumGetPointer(indclassDatum);
     990           6 :         opclass = indclass->values[attnum - 1];
     991             : 
     992           6 :         ereport(ERROR,
     993             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     994             :                  errmsg("operator class %s has no options",
     995             :                         generate_opclass_name(opclass))));
     996             :     }
     997             : 
     998        2484 :     init_local_reloptions(&relopts, 0);
     999             : 
    1000        2484 :     procinfo = index_getprocinfo(indrel, attnum, amoptsprocnum);
    1001             : 
    1002        2484 :     (void) FunctionCall1(procinfo, PointerGetDatum(&relopts));
    1003             : 
    1004        2484 :     return build_local_reloptions(&relopts, attoptions, validate);
    1005             : }

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