LCOV - code coverage report
Current view: top level - src/backend/access/heap - heapam_handler.c (source / functions) Hit Total Coverage
Test: PostgreSQL 19devel Lines: 736 792 92.9 %
Date: 2026-01-15 16:18:36 Functions: 34 34 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * heapam_handler.c
       4             :  *    heap table access method code
       5             :  *
       6             :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/access/heap/heapam_handler.c
      12             :  *
      13             :  *
      14             :  * NOTES
      15             :  *    This files wires up the lower level heapam.c et al routines with the
      16             :  *    tableam abstraction.
      17             :  *
      18             :  *-------------------------------------------------------------------------
      19             :  */
      20             : #include "postgres.h"
      21             : 
      22             : #include "access/genam.h"
      23             : #include "access/heapam.h"
      24             : #include "access/heaptoast.h"
      25             : #include "access/multixact.h"
      26             : #include "access/rewriteheap.h"
      27             : #include "access/syncscan.h"
      28             : #include "access/tableam.h"
      29             : #include "access/tsmapi.h"
      30             : #include "access/visibilitymap.h"
      31             : #include "access/xact.h"
      32             : #include "catalog/catalog.h"
      33             : #include "catalog/index.h"
      34             : #include "catalog/storage.h"
      35             : #include "catalog/storage_xlog.h"
      36             : #include "commands/progress.h"
      37             : #include "executor/executor.h"
      38             : #include "miscadmin.h"
      39             : #include "pgstat.h"
      40             : #include "storage/bufmgr.h"
      41             : #include "storage/bufpage.h"
      42             : #include "storage/lmgr.h"
      43             : #include "storage/predicate.h"
      44             : #include "storage/procarray.h"
      45             : #include "storage/smgr.h"
      46             : #include "utils/builtins.h"
      47             : #include "utils/rel.h"
      48             : 
      49             : static void reform_and_rewrite_tuple(HeapTuple tuple,
      50             :                                      Relation OldHeap, Relation NewHeap,
      51             :                                      Datum *values, bool *isnull, RewriteState rwstate);
      52             : 
      53             : static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
      54             :                                    HeapTuple tuple,
      55             :                                    OffsetNumber tupoffset);
      56             : 
      57             : static BlockNumber heapam_scan_get_blocks_done(HeapScanDesc hscan);
      58             : 
      59             : static bool BitmapHeapScanNextBlock(TableScanDesc scan,
      60             :                                     bool *recheck,
      61             :                                     uint64 *lossy_pages, uint64 *exact_pages);
      62             : 
      63             : 
      64             : /* ------------------------------------------------------------------------
      65             :  * Slot related callbacks for heap AM
      66             :  * ------------------------------------------------------------------------
      67             :  */
      68             : 
      69             : static const TupleTableSlotOps *
      70    28799836 : heapam_slot_callbacks(Relation relation)
      71             : {
      72    28799836 :     return &TTSOpsBufferHeapTuple;
      73             : }
      74             : 
      75             : 
      76             : /* ------------------------------------------------------------------------
      77             :  * Index Scan Callbacks for heap AM
      78             :  * ------------------------------------------------------------------------
      79             :  */
      80             : 
      81             : static IndexFetchTableData *
      82    27601730 : heapam_index_fetch_begin(Relation rel)
      83             : {
      84    27601730 :     IndexFetchHeapData *hscan = palloc0_object(IndexFetchHeapData);
      85             : 
      86    27601730 :     hscan->xs_base.rel = rel;
      87    27601730 :     hscan->xs_cbuf = InvalidBuffer;
      88             : 
      89    27601730 :     return &hscan->xs_base;
      90             : }
      91             : 
      92             : static void
      93    51716682 : heapam_index_fetch_reset(IndexFetchTableData *scan)
      94             : {
      95    51716682 :     IndexFetchHeapData *hscan = (IndexFetchHeapData *) scan;
      96             : 
      97    51716682 :     if (BufferIsValid(hscan->xs_cbuf))
      98             :     {
      99    23464534 :         ReleaseBuffer(hscan->xs_cbuf);
     100    23464534 :         hscan->xs_cbuf = InvalidBuffer;
     101             :     }
     102    51716682 : }
     103             : 
     104             : static void
     105    27599932 : heapam_index_fetch_end(IndexFetchTableData *scan)
     106             : {
     107    27599932 :     IndexFetchHeapData *hscan = (IndexFetchHeapData *) scan;
     108             : 
     109    27599932 :     heapam_index_fetch_reset(scan);
     110             : 
     111    27599932 :     pfree(hscan);
     112    27599932 : }
     113             : 
     114             : static bool
     115    39585228 : heapam_index_fetch_tuple(struct IndexFetchTableData *scan,
     116             :                          ItemPointer tid,
     117             :                          Snapshot snapshot,
     118             :                          TupleTableSlot *slot,
     119             :                          bool *call_again, bool *all_dead)
     120             : {
     121    39585228 :     IndexFetchHeapData *hscan = (IndexFetchHeapData *) scan;
     122    39585228 :     BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
     123             :     bool        got_heap_tuple;
     124             : 
     125             :     Assert(TTS_IS_BUFFERTUPLE(slot));
     126             : 
     127             :     /* We can skip the buffer-switching logic if we're in mid-HOT chain. */
     128    39585228 :     if (!*call_again)
     129             :     {
     130             :         /* Switch to correct buffer if we don't have it already */
     131    39411066 :         Buffer      prev_buf = hscan->xs_cbuf;
     132             : 
     133    39411066 :         hscan->xs_cbuf = ReleaseAndReadBuffer(hscan->xs_cbuf,
     134             :                                               hscan->xs_base.rel,
     135             :                                               ItemPointerGetBlockNumber(tid));
     136             : 
     137             :         /*
     138             :          * Prune page, but only if we weren't already on this page
     139             :          */
     140    39411060 :         if (prev_buf != hscan->xs_cbuf)
     141    27315410 :             heap_page_prune_opt(hscan->xs_base.rel, hscan->xs_cbuf);
     142             :     }
     143             : 
     144             :     /* Obtain share-lock on the buffer so we can examine visibility */
     145    39585222 :     LockBuffer(hscan->xs_cbuf, BUFFER_LOCK_SHARE);
     146    39585222 :     got_heap_tuple = heap_hot_search_buffer(tid,
     147             :                                             hscan->xs_base.rel,
     148             :                                             hscan->xs_cbuf,
     149             :                                             snapshot,
     150             :                                             &bslot->base.tupdata,
     151             :                                             all_dead,
     152    39585222 :                                             !*call_again);
     153    39585218 :     bslot->base.tupdata.t_self = *tid;
     154    39585218 :     LockBuffer(hscan->xs_cbuf, BUFFER_LOCK_UNLOCK);
     155             : 
     156    39585218 :     if (got_heap_tuple)
     157             :     {
     158             :         /*
     159             :          * Only in a non-MVCC snapshot can more than one member of the HOT
     160             :          * chain be visible.
     161             :          */
     162    26924378 :         *call_again = !IsMVCCSnapshot(snapshot);
     163             : 
     164    26924378 :         slot->tts_tableOid = RelationGetRelid(scan->rel);
     165    26924378 :         ExecStoreBufferHeapTuple(&bslot->base.tupdata, slot, hscan->xs_cbuf);
     166             :     }
     167             :     else
     168             :     {
     169             :         /* We've reached the end of the HOT chain. */
     170    12660840 :         *call_again = false;
     171             :     }
     172             : 
     173    39585218 :     return got_heap_tuple;
     174             : }
     175             : 
     176             : 
     177             : /* ------------------------------------------------------------------------
     178             :  * Callbacks for non-modifying operations on individual tuples for heap AM
     179             :  * ------------------------------------------------------------------------
     180             :  */
     181             : 
     182             : static bool
     183      357752 : heapam_fetch_row_version(Relation relation,
     184             :                          ItemPointer tid,
     185             :                          Snapshot snapshot,
     186             :                          TupleTableSlot *slot)
     187             : {
     188      357752 :     BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
     189             :     Buffer      buffer;
     190             : 
     191             :     Assert(TTS_IS_BUFFERTUPLE(slot));
     192             : 
     193      357752 :     bslot->base.tupdata.t_self = *tid;
     194      357752 :     if (heap_fetch(relation, snapshot, &bslot->base.tupdata, &buffer, false))
     195             :     {
     196             :         /* store in slot, transferring existing pin */
     197      357024 :         ExecStorePinnedBufferHeapTuple(&bslot->base.tupdata, slot, buffer);
     198      357024 :         slot->tts_tableOid = RelationGetRelid(relation);
     199             : 
     200      357024 :         return true;
     201             :     }
     202             : 
     203         712 :     return false;
     204             : }
     205             : 
     206             : static bool
     207         766 : heapam_tuple_tid_valid(TableScanDesc scan, ItemPointer tid)
     208             : {
     209         766 :     HeapScanDesc hscan = (HeapScanDesc) scan;
     210             : 
     211        1514 :     return ItemPointerIsValid(tid) &&
     212         748 :         ItemPointerGetBlockNumber(tid) < hscan->rs_nblocks;
     213             : }
     214             : 
     215             : static bool
     216      255248 : heapam_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot,
     217             :                                 Snapshot snapshot)
     218             : {
     219      255248 :     BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
     220             :     bool        res;
     221             : 
     222             :     Assert(TTS_IS_BUFFERTUPLE(slot));
     223             :     Assert(BufferIsValid(bslot->buffer));
     224             : 
     225             :     /*
     226             :      * We need buffer pin and lock to call HeapTupleSatisfiesVisibility.
     227             :      * Caller should be holding pin, but not lock.
     228             :      */
     229      255248 :     LockBuffer(bslot->buffer, BUFFER_LOCK_SHARE);
     230      255248 :     res = HeapTupleSatisfiesVisibility(bslot->base.tuple, snapshot,
     231             :                                        bslot->buffer);
     232      255248 :     LockBuffer(bslot->buffer, BUFFER_LOCK_UNLOCK);
     233             : 
     234      255248 :     return res;
     235             : }
     236             : 
     237             : 
     238             : /* ----------------------------------------------------------------------------
     239             :  *  Functions for manipulations of physical tuples for heap AM.
     240             :  * ----------------------------------------------------------------------------
     241             :  */
     242             : 
     243             : static void
     244    14843262 : heapam_tuple_insert(Relation relation, TupleTableSlot *slot, CommandId cid,
     245             :                     int options, BulkInsertState bistate)
     246             : {
     247    14843262 :     bool        shouldFree = true;
     248    14843262 :     HeapTuple   tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
     249             : 
     250             :     /* Update the tuple with table oid */
     251    14843262 :     slot->tts_tableOid = RelationGetRelid(relation);
     252    14843262 :     tuple->t_tableOid = slot->tts_tableOid;
     253             : 
     254             :     /* Perform the insertion, and copy the resulting ItemPointer */
     255    14843262 :     heap_insert(relation, tuple, cid, options, bistate);
     256    14843224 :     ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
     257             : 
     258    14843224 :     if (shouldFree)
     259     2967996 :         pfree(tuple);
     260    14843224 : }
     261             : 
     262             : static void
     263        4196 : heapam_tuple_insert_speculative(Relation relation, TupleTableSlot *slot,
     264             :                                 CommandId cid, int options,
     265             :                                 BulkInsertState bistate, uint32 specToken)
     266             : {
     267        4196 :     bool        shouldFree = true;
     268        4196 :     HeapTuple   tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
     269             : 
     270             :     /* Update the tuple with table oid */
     271        4196 :     slot->tts_tableOid = RelationGetRelid(relation);
     272        4196 :     tuple->t_tableOid = slot->tts_tableOid;
     273             : 
     274        4196 :     HeapTupleHeaderSetSpeculativeToken(tuple->t_data, specToken);
     275        4196 :     options |= HEAP_INSERT_SPECULATIVE;
     276             : 
     277             :     /* Perform the insertion, and copy the resulting ItemPointer */
     278        4196 :     heap_insert(relation, tuple, cid, options, bistate);
     279        4196 :     ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
     280             : 
     281        4196 :     if (shouldFree)
     282          82 :         pfree(tuple);
     283        4196 : }
     284             : 
     285             : static void
     286        4190 : heapam_tuple_complete_speculative(Relation relation, TupleTableSlot *slot,
     287             :                                   uint32 specToken, bool succeeded)
     288             : {
     289        4190 :     bool        shouldFree = true;
     290        4190 :     HeapTuple   tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
     291             : 
     292             :     /* adjust the tuple's state accordingly */
     293        4190 :     if (succeeded)
     294        4168 :         heap_finish_speculative(relation, &slot->tts_tid);
     295             :     else
     296          22 :         heap_abort_speculative(relation, &slot->tts_tid);
     297             : 
     298        4190 :     if (shouldFree)
     299          82 :         pfree(tuple);
     300        4190 : }
     301             : 
     302             : static TM_Result
     303     1731952 : heapam_tuple_delete(Relation relation, ItemPointer tid, CommandId cid,
     304             :                     Snapshot snapshot, Snapshot crosscheck, bool wait,
     305             :                     TM_FailureData *tmfd, bool changingPart)
     306             : {
     307             :     /*
     308             :      * Currently Deleting of index tuples are handled at vacuum, in case if
     309             :      * the storage itself is cleaning the dead tuples by itself, it is the
     310             :      * time to call the index tuple deletion also.
     311             :      */
     312     1731952 :     return heap_delete(relation, tid, cid, crosscheck, wait, tmfd, changingPart);
     313             : }
     314             : 
     315             : 
     316             : static TM_Result
     317      389472 : heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
     318             :                     CommandId cid, Snapshot snapshot, Snapshot crosscheck,
     319             :                     bool wait, TM_FailureData *tmfd,
     320             :                     LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes)
     321             : {
     322      389472 :     bool        shouldFree = true;
     323      389472 :     HeapTuple   tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
     324             :     TM_Result   result;
     325             : 
     326             :     /* Update the tuple with table oid */
     327      389472 :     slot->tts_tableOid = RelationGetRelid(relation);
     328      389472 :     tuple->t_tableOid = slot->tts_tableOid;
     329             : 
     330      389472 :     result = heap_update(relation, otid, tuple, cid, crosscheck, wait,
     331             :                          tmfd, lockmode, update_indexes);
     332      389448 :     ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
     333             : 
     334             :     /*
     335             :      * Decide whether new index entries are needed for the tuple
     336             :      *
     337             :      * Note: heap_update returns the tid (location) of the new tuple in the
     338             :      * t_self field.
     339             :      *
     340             :      * If the update is not HOT, we must update all indexes. If the update is
     341             :      * HOT, it could be that we updated summarized columns, so we either
     342             :      * update only summarized indexes, or none at all.
     343             :      */
     344      389448 :     if (result != TM_Ok)
     345             :     {
     346             :         Assert(*update_indexes == TU_None);
     347         316 :         *update_indexes = TU_None;
     348             :     }
     349      389132 :     else if (!HeapTupleIsHeapOnly(tuple))
     350             :         Assert(*update_indexes == TU_All);
     351             :     else
     352             :         Assert((*update_indexes == TU_Summarizing) ||
     353             :                (*update_indexes == TU_None));
     354             : 
     355      389448 :     if (shouldFree)
     356       63888 :         pfree(tuple);
     357             : 
     358      389448 :     return result;
     359             : }
     360             : 
     361             : static TM_Result
     362      316452 : heapam_tuple_lock(Relation relation, ItemPointer tid, Snapshot snapshot,
     363             :                   TupleTableSlot *slot, CommandId cid, LockTupleMode mode,
     364             :                   LockWaitPolicy wait_policy, uint8 flags,
     365             :                   TM_FailureData *tmfd)
     366             : {
     367      316452 :     BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot;
     368             :     TM_Result   result;
     369             :     Buffer      buffer;
     370      316452 :     HeapTuple   tuple = &bslot->base.tupdata;
     371             :     bool        follow_updates;
     372             : 
     373      316452 :     follow_updates = (flags & TUPLE_LOCK_FLAG_LOCK_UPDATE_IN_PROGRESS) != 0;
     374      316452 :     tmfd->traversed = false;
     375             : 
     376             :     Assert(TTS_IS_BUFFERTUPLE(slot));
     377             : 
     378      316792 : tuple_lock_retry:
     379      316792 :     tuple->t_self = *tid;
     380      316792 :     result = heap_lock_tuple(relation, tuple, cid, mode, wait_policy,
     381             :                              follow_updates, &buffer, tmfd);
     382             : 
     383      316774 :     if (result == TM_Updated &&
     384         420 :         (flags & TUPLE_LOCK_FLAG_FIND_LAST_VERSION))
     385             :     {
     386             :         /* Should not encounter speculative tuple on recheck */
     387             :         Assert(!HeapTupleHeaderIsSpeculative(tuple->t_data));
     388             : 
     389         386 :         ReleaseBuffer(buffer);
     390             : 
     391         386 :         if (!ItemPointerEquals(&tmfd->ctid, &tuple->t_self))
     392             :         {
     393             :             SnapshotData SnapshotDirty;
     394             :             TransactionId priorXmax;
     395             : 
     396             :             /* it was updated, so look at the updated version */
     397         386 :             *tid = tmfd->ctid;
     398             :             /* updated row should have xmin matching this xmax */
     399         386 :             priorXmax = tmfd->xmax;
     400             : 
     401             :             /* signal that a tuple later in the chain is getting locked */
     402         386 :             tmfd->traversed = true;
     403             : 
     404             :             /*
     405             :              * fetch target tuple
     406             :              *
     407             :              * Loop here to deal with updated or busy tuples
     408             :              */
     409         386 :             InitDirtySnapshot(SnapshotDirty);
     410             :             for (;;)
     411             :             {
     412         448 :                 if (ItemPointerIndicatesMovedPartitions(tid))
     413          22 :                     ereport(ERROR,
     414             :                             (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
     415             :                              errmsg("tuple to be locked was already moved to another partition due to concurrent update")));
     416             : 
     417         426 :                 tuple->t_self = *tid;
     418         426 :                 if (heap_fetch(relation, &SnapshotDirty, tuple, &buffer, true))
     419             :                 {
     420             :                     /*
     421             :                      * If xmin isn't what we're expecting, the slot must have
     422             :                      * been recycled and reused for an unrelated tuple.  This
     423             :                      * implies that the latest version of the row was deleted,
     424             :                      * so we need do nothing.  (Should be safe to examine xmin
     425             :                      * without getting buffer's content lock.  We assume
     426             :                      * reading a TransactionId to be atomic, and Xmin never
     427             :                      * changes in an existing tuple, except to invalid or
     428             :                      * frozen, and neither of those can match priorXmax.)
     429             :                      */
     430         358 :                     if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple->t_data),
     431             :                                              priorXmax))
     432             :                     {
     433           0 :                         ReleaseBuffer(buffer);
     434          22 :                         return TM_Deleted;
     435             :                     }
     436             : 
     437             :                     /* otherwise xmin should not be dirty... */
     438         358 :                     if (TransactionIdIsValid(SnapshotDirty.xmin))
     439           0 :                         ereport(ERROR,
     440             :                                 (errcode(ERRCODE_DATA_CORRUPTED),
     441             :                                  errmsg_internal("t_xmin %u is uncommitted in tuple (%u,%u) to be updated in table \"%s\"",
     442             :                                                  SnapshotDirty.xmin,
     443             :                                                  ItemPointerGetBlockNumber(&tuple->t_self),
     444             :                                                  ItemPointerGetOffsetNumber(&tuple->t_self),
     445             :                                                  RelationGetRelationName(relation))));
     446             : 
     447             :                     /*
     448             :                      * If tuple is being updated by other transaction then we
     449             :                      * have to wait for its commit/abort, or die trying.
     450             :                      */
     451         358 :                     if (TransactionIdIsValid(SnapshotDirty.xmax))
     452             :                     {
     453           4 :                         ReleaseBuffer(buffer);
     454           4 :                         switch (wait_policy)
     455             :                         {
     456           0 :                             case LockWaitBlock:
     457           0 :                                 XactLockTableWait(SnapshotDirty.xmax,
     458           0 :                                                   relation, &tuple->t_self,
     459             :                                                   XLTW_FetchUpdated);
     460           0 :                                 break;
     461           2 :                             case LockWaitSkip:
     462           2 :                                 if (!ConditionalXactLockTableWait(SnapshotDirty.xmax, false))
     463             :                                     /* skip instead of waiting */
     464           2 :                                     return TM_WouldBlock;
     465           0 :                                 break;
     466           2 :                             case LockWaitError:
     467           2 :                                 if (!ConditionalXactLockTableWait(SnapshotDirty.xmax, log_lock_failures))
     468           2 :                                     ereport(ERROR,
     469             :                                             (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
     470             :                                              errmsg("could not obtain lock on row in relation \"%s\"",
     471             :                                                     RelationGetRelationName(relation))));
     472           0 :                                 break;
     473             :                         }
     474           0 :                         continue;   /* loop back to repeat heap_fetch */
     475             :                     }
     476             : 
     477             :                     /*
     478             :                      * If tuple was inserted by our own transaction, we have
     479             :                      * to check cmin against cid: cmin >= current CID means
     480             :                      * our command cannot see the tuple, so we should ignore
     481             :                      * it. Otherwise heap_lock_tuple() will throw an error,
     482             :                      * and so would any later attempt to update or delete the
     483             :                      * tuple.  (We need not check cmax because
     484             :                      * HeapTupleSatisfiesDirty will consider a tuple deleted
     485             :                      * by our transaction dead, regardless of cmax.)  We just
     486             :                      * checked that priorXmax == xmin, so we can test that
     487             :                      * variable instead of doing HeapTupleHeaderGetXmin again.
     488             :                      */
     489         368 :                     if (TransactionIdIsCurrentTransactionId(priorXmax) &&
     490          14 :                         HeapTupleHeaderGetCmin(tuple->t_data) >= cid)
     491             :                     {
     492          14 :                         tmfd->xmax = priorXmax;
     493             : 
     494             :                         /*
     495             :                          * Cmin is the problematic value, so store that. See
     496             :                          * above.
     497             :                          */
     498          14 :                         tmfd->cmax = HeapTupleHeaderGetCmin(tuple->t_data);
     499          14 :                         ReleaseBuffer(buffer);
     500          14 :                         return TM_SelfModified;
     501             :                     }
     502             : 
     503             :                     /*
     504             :                      * This is a live tuple, so try to lock it again.
     505             :                      */
     506         340 :                     ReleaseBuffer(buffer);
     507         340 :                     goto tuple_lock_retry;
     508             :                 }
     509             : 
     510             :                 /*
     511             :                  * If the referenced slot was actually empty, the latest
     512             :                  * version of the row must have been deleted, so we need do
     513             :                  * nothing.
     514             :                  */
     515          68 :                 if (tuple->t_data == NULL)
     516             :                 {
     517             :                     Assert(!BufferIsValid(buffer));
     518           0 :                     return TM_Deleted;
     519             :                 }
     520             : 
     521             :                 /*
     522             :                  * As above, if xmin isn't what we're expecting, do nothing.
     523             :                  */
     524          68 :                 if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple->t_data),
     525             :                                          priorXmax))
     526             :                 {
     527           0 :                     ReleaseBuffer(buffer);
     528           0 :                     return TM_Deleted;
     529             :                 }
     530             : 
     531             :                 /*
     532             :                  * If we get here, the tuple was found but failed
     533             :                  * SnapshotDirty. Assuming the xmin is either a committed xact
     534             :                  * or our own xact (as it certainly should be if we're trying
     535             :                  * to modify the tuple), this must mean that the row was
     536             :                  * updated or deleted by either a committed xact or our own
     537             :                  * xact.  If it was deleted, we can ignore it; if it was
     538             :                  * updated then chain up to the next version and repeat the
     539             :                  * whole process.
     540             :                  *
     541             :                  * As above, it should be safe to examine xmax and t_ctid
     542             :                  * without the buffer content lock, because they can't be
     543             :                  * changing.  We'd better hold a buffer pin though.
     544             :                  */
     545          68 :                 if (ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid))
     546             :                 {
     547             :                     /* deleted, so forget about it */
     548           6 :                     ReleaseBuffer(buffer);
     549           6 :                     return TM_Deleted;
     550             :                 }
     551             : 
     552             :                 /* updated, so look at the updated row */
     553          62 :                 *tid = tuple->t_data->t_ctid;
     554             :                 /* updated row should have xmin matching this xmax */
     555          62 :                 priorXmax = HeapTupleHeaderGetUpdateXid(tuple->t_data);
     556          62 :                 ReleaseBuffer(buffer);
     557             :                 /* loop back to fetch next in chain */
     558             :             }
     559             :         }
     560             :         else
     561             :         {
     562             :             /* tuple was deleted, so give up */
     563           0 :             return TM_Deleted;
     564             :         }
     565             :     }
     566             : 
     567      316388 :     slot->tts_tableOid = RelationGetRelid(relation);
     568      316388 :     tuple->t_tableOid = slot->tts_tableOid;
     569             : 
     570             :     /* store in slot, transferring existing pin */
     571      316388 :     ExecStorePinnedBufferHeapTuple(tuple, slot, buffer);
     572             : 
     573      316388 :     return result;
     574             : }
     575             : 
     576             : 
     577             : /* ------------------------------------------------------------------------
     578             :  * DDL related callbacks for heap AM.
     579             :  * ------------------------------------------------------------------------
     580             :  */
     581             : 
     582             : static void
     583       67560 : heapam_relation_set_new_filelocator(Relation rel,
     584             :                                     const RelFileLocator *newrlocator,
     585             :                                     char persistence,
     586             :                                     TransactionId *freezeXid,
     587             :                                     MultiXactId *minmulti)
     588             : {
     589             :     SMgrRelation srel;
     590             : 
     591             :     /*
     592             :      * Initialize to the minimum XID that could put tuples in the table. We
     593             :      * know that no xacts older than RecentXmin are still running, so that
     594             :      * will do.
     595             :      */
     596       67560 :     *freezeXid = RecentXmin;
     597             : 
     598             :     /*
     599             :      * Similarly, initialize the minimum Multixact to the first value that
     600             :      * could possibly be stored in tuples in the table.  Running transactions
     601             :      * could reuse values from their local cache, so we are careful to
     602             :      * consider all currently running multis.
     603             :      *
     604             :      * XXX this could be refined further, but is it worth the hassle?
     605             :      */
     606       67560 :     *minmulti = GetOldestMultiXactId();
     607             : 
     608       67560 :     srel = RelationCreateStorage(*newrlocator, persistence, true);
     609             : 
     610             :     /*
     611             :      * If required, set up an init fork for an unlogged table so that it can
     612             :      * be correctly reinitialized on restart.
     613             :      */
     614       67560 :     if (persistence == RELPERSISTENCE_UNLOGGED)
     615             :     {
     616             :         Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
     617             :                rel->rd_rel->relkind == RELKIND_TOASTVALUE);
     618         270 :         smgrcreate(srel, INIT_FORKNUM, false);
     619         270 :         log_smgrcreate(newrlocator, INIT_FORKNUM);
     620             :     }
     621             : 
     622       67560 :     smgrclose(srel);
     623       67560 : }
     624             : 
     625             : static void
     626         624 : heapam_relation_nontransactional_truncate(Relation rel)
     627             : {
     628         624 :     RelationTruncate(rel, 0);
     629         624 : }
     630             : 
     631             : static void
     632          98 : heapam_relation_copy_data(Relation rel, const RelFileLocator *newrlocator)
     633             : {
     634             :     SMgrRelation dstrel;
     635             : 
     636             :     /*
     637             :      * Since we copy the file directly without looking at the shared buffers,
     638             :      * we'd better first flush out any pages of the source relation that are
     639             :      * in shared buffers.  We assume no new changes will be made while we are
     640             :      * holding exclusive lock on the rel.
     641             :      */
     642          98 :     FlushRelationBuffers(rel);
     643             : 
     644             :     /*
     645             :      * Create and copy all forks of the relation, and schedule unlinking of
     646             :      * old physical files.
     647             :      *
     648             :      * NOTE: any conflict in relfilenumber value will be caught in
     649             :      * RelationCreateStorage().
     650             :      */
     651          98 :     dstrel = RelationCreateStorage(*newrlocator, rel->rd_rel->relpersistence, true);
     652             : 
     653             :     /* copy main fork */
     654          98 :     RelationCopyStorage(RelationGetSmgr(rel), dstrel, MAIN_FORKNUM,
     655          98 :                         rel->rd_rel->relpersistence);
     656             : 
     657             :     /* copy those extra forks that exist */
     658          98 :     for (ForkNumber forkNum = MAIN_FORKNUM + 1;
     659         392 :          forkNum <= MAX_FORKNUM; forkNum++)
     660             :     {
     661         294 :         if (smgrexists(RelationGetSmgr(rel), forkNum))
     662             :         {
     663          18 :             smgrcreate(dstrel, forkNum, false);
     664             : 
     665             :             /*
     666             :              * WAL log creation if the relation is persistent, or this is the
     667             :              * init fork of an unlogged relation.
     668             :              */
     669          18 :             if (RelationIsPermanent(rel) ||
     670           6 :                 (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
     671             :                  forkNum == INIT_FORKNUM))
     672          12 :                 log_smgrcreate(newrlocator, forkNum);
     673          18 :             RelationCopyStorage(RelationGetSmgr(rel), dstrel, forkNum,
     674          18 :                                 rel->rd_rel->relpersistence);
     675             :         }
     676             :     }
     677             : 
     678             : 
     679             :     /* drop old relation, and close new one */
     680          98 :     RelationDropStorage(rel);
     681          98 :     smgrclose(dstrel);
     682          98 : }
     683             : 
     684             : static void
     685         568 : heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
     686             :                                  Relation OldIndex, bool use_sort,
     687             :                                  TransactionId OldestXmin,
     688             :                                  TransactionId *xid_cutoff,
     689             :                                  MultiXactId *multi_cutoff,
     690             :                                  double *num_tuples,
     691             :                                  double *tups_vacuumed,
     692             :                                  double *tups_recently_dead)
     693             : {
     694             :     RewriteState rwstate;
     695             :     IndexScanDesc indexScan;
     696             :     TableScanDesc tableScan;
     697             :     HeapScanDesc heapScan;
     698             :     bool        is_system_catalog;
     699             :     Tuplesortstate *tuplesort;
     700         568 :     TupleDesc   oldTupDesc = RelationGetDescr(OldHeap);
     701         568 :     TupleDesc   newTupDesc = RelationGetDescr(NewHeap);
     702             :     TupleTableSlot *slot;
     703             :     int         natts;
     704             :     Datum      *values;
     705             :     bool       *isnull;
     706             :     BufferHeapTupleTableSlot *hslot;
     707         568 :     BlockNumber prev_cblock = InvalidBlockNumber;
     708             : 
     709             :     /* Remember if it's a system catalog */
     710         568 :     is_system_catalog = IsSystemRelation(OldHeap);
     711             : 
     712             :     /*
     713             :      * Valid smgr_targblock implies something already wrote to the relation.
     714             :      * This may be harmless, but this function hasn't planned for it.
     715             :      */
     716             :     Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
     717             : 
     718             :     /* Preallocate values/isnull arrays */
     719         568 :     natts = newTupDesc->natts;
     720         568 :     values = palloc_array(Datum, natts);
     721         568 :     isnull = palloc_array(bool, natts);
     722             : 
     723             :     /* Initialize the rewrite operation */
     724         568 :     rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin, *xid_cutoff,
     725             :                                  *multi_cutoff);
     726             : 
     727             : 
     728             :     /* Set up sorting if wanted */
     729         568 :     if (use_sort)
     730         110 :         tuplesort = tuplesort_begin_cluster(oldTupDesc, OldIndex,
     731             :                                             maintenance_work_mem,
     732             :                                             NULL, TUPLESORT_NONE);
     733             :     else
     734         458 :         tuplesort = NULL;
     735             : 
     736             :     /*
     737             :      * Prepare to scan the OldHeap.  To ensure we see recently-dead tuples
     738             :      * that still need to be copied, we scan with SnapshotAny and use
     739             :      * HeapTupleSatisfiesVacuum for the visibility test.
     740             :      */
     741         568 :     if (OldIndex != NULL && !use_sort)
     742          78 :     {
     743          78 :         const int   ci_index[] = {
     744             :             PROGRESS_CLUSTER_PHASE,
     745             :             PROGRESS_CLUSTER_INDEX_RELID
     746             :         };
     747             :         int64       ci_val[2];
     748             : 
     749             :         /* Set phase and OIDOldIndex to columns */
     750          78 :         ci_val[0] = PROGRESS_CLUSTER_PHASE_INDEX_SCAN_HEAP;
     751          78 :         ci_val[1] = RelationGetRelid(OldIndex);
     752          78 :         pgstat_progress_update_multi_param(2, ci_index, ci_val);
     753             : 
     754          78 :         tableScan = NULL;
     755          78 :         heapScan = NULL;
     756          78 :         indexScan = index_beginscan(OldHeap, OldIndex, SnapshotAny, NULL, 0, 0);
     757          78 :         index_rescan(indexScan, NULL, 0, NULL, 0);
     758             :     }
     759             :     else
     760             :     {
     761             :         /* In scan-and-sort mode and also VACUUM FULL, set phase */
     762         490 :         pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
     763             :                                      PROGRESS_CLUSTER_PHASE_SEQ_SCAN_HEAP);
     764             : 
     765         490 :         tableScan = table_beginscan(OldHeap, SnapshotAny, 0, (ScanKey) NULL);
     766         490 :         heapScan = (HeapScanDesc) tableScan;
     767         490 :         indexScan = NULL;
     768             : 
     769             :         /* Set total heap blocks */
     770         490 :         pgstat_progress_update_param(PROGRESS_CLUSTER_TOTAL_HEAP_BLKS,
     771         490 :                                      heapScan->rs_nblocks);
     772             :     }
     773             : 
     774         568 :     slot = table_slot_create(OldHeap, NULL);
     775         568 :     hslot = (BufferHeapTupleTableSlot *) slot;
     776             : 
     777             :     /*
     778             :      * Scan through the OldHeap, either in OldIndex order or sequentially;
     779             :      * copy each tuple into the NewHeap, or transiently to the tuplesort
     780             :      * module.  Note that we don't bother sorting dead tuples (they won't get
     781             :      * to the new table anyway).
     782             :      */
     783             :     for (;;)
     784      761470 :     {
     785             :         HeapTuple   tuple;
     786             :         Buffer      buf;
     787             :         bool        isdead;
     788             : 
     789      762038 :         CHECK_FOR_INTERRUPTS();
     790             : 
     791      762038 :         if (indexScan != NULL)
     792             :         {
     793         186 :             if (!index_getnext_slot(indexScan, ForwardScanDirection, slot))
     794          78 :                 break;
     795             : 
     796             :             /* Since we used no scan keys, should never need to recheck */
     797         108 :             if (indexScan->xs_recheck)
     798           0 :                 elog(ERROR, "CLUSTER does not support lossy index conditions");
     799             :         }
     800             :         else
     801             :         {
     802      761852 :             if (!table_scan_getnextslot(tableScan, ForwardScanDirection, slot))
     803             :             {
     804             :                 /*
     805             :                  * If the last pages of the scan were empty, we would go to
     806             :                  * the next phase while heap_blks_scanned != heap_blks_total.
     807             :                  * Instead, to ensure that heap_blks_scanned is equivalent to
     808             :                  * heap_blks_total after the table scan phase, this parameter
     809             :                  * is manually updated to the correct value when the table
     810             :                  * scan finishes.
     811             :                  */
     812         490 :                 pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_BLKS_SCANNED,
     813         490 :                                              heapScan->rs_nblocks);
     814         490 :                 break;
     815             :             }
     816             : 
     817             :             /*
     818             :              * In scan-and-sort mode and also VACUUM FULL, set heap blocks
     819             :              * scanned
     820             :              *
     821             :              * Note that heapScan may start at an offset and wrap around, i.e.
     822             :              * rs_startblock may be >0, and rs_cblock may end with a number
     823             :              * below rs_startblock. To prevent showing this wraparound to the
     824             :              * user, we offset rs_cblock by rs_startblock (modulo rs_nblocks).
     825             :              */
     826      761362 :             if (prev_cblock != heapScan->rs_cblock)
     827             :             {
     828       11184 :                 pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_BLKS_SCANNED,
     829       11184 :                                              (heapScan->rs_cblock +
     830       11184 :                                               heapScan->rs_nblocks -
     831       11184 :                                               heapScan->rs_startblock
     832       11184 :                                               ) % heapScan->rs_nblocks + 1);
     833       11184 :                 prev_cblock = heapScan->rs_cblock;
     834             :             }
     835             :         }
     836             : 
     837      761470 :         tuple = ExecFetchSlotHeapTuple(slot, false, NULL);
     838      761470 :         buf = hslot->buffer;
     839             : 
     840             :         /*
     841             :          * To be able to guarantee that we can set the hint bit, acquire an
     842             :          * exclusive lock on the old buffer. We need the hint bits, set in
     843             :          * heapam_relation_copy_for_cluster() -> HeapTupleSatisfiesVacuum(),
     844             :          * to be set, as otherwise reform_and_rewrite_tuple() ->
     845             :          * rewrite_heap_tuple() will get confused. Specifically,
     846             :          * rewrite_heap_tuple() checks for HEAP_XMAX_INVALID in the old tuple
     847             :          * to determine whether to check the old-to-new mapping hash table.
     848             :          *
     849             :          * It'd be better if we somehow could avoid setting hint bits on the
     850             :          * old page. One reason to use VACUUM FULL are very bloated tables -
     851             :          * rewriting most of the old table during VACUUM FULL doesn't exactly
     852             :          * help...
     853             :          */
     854      761470 :         LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
     855             : 
     856      761470 :         switch (HeapTupleSatisfiesVacuum(tuple, OldestXmin, buf))
     857             :         {
     858       33146 :             case HEAPTUPLE_DEAD:
     859             :                 /* Definitely dead */
     860       33146 :                 isdead = true;
     861       33146 :                 break;
     862       33826 :             case HEAPTUPLE_RECENTLY_DEAD:
     863       33826 :                 *tups_recently_dead += 1;
     864             :                 /* fall through */
     865      728114 :             case HEAPTUPLE_LIVE:
     866             :                 /* Live or recently dead, must copy it */
     867      728114 :                 isdead = false;
     868      728114 :                 break;
     869         160 :             case HEAPTUPLE_INSERT_IN_PROGRESS:
     870             : 
     871             :                 /*
     872             :                  * Since we hold exclusive lock on the relation, normally the
     873             :                  * only way to see this is if it was inserted earlier in our
     874             :                  * own transaction.  However, it can happen in system
     875             :                  * catalogs, since we tend to release write lock before commit
     876             :                  * there.  Give a warning if neither case applies; but in any
     877             :                  * case we had better copy it.
     878             :                  */
     879         160 :                 if (!is_system_catalog &&
     880          22 :                     !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data)))
     881           0 :                     elog(WARNING, "concurrent insert in progress within table \"%s\"",
     882             :                          RelationGetRelationName(OldHeap));
     883             :                 /* treat as live */
     884         160 :                 isdead = false;
     885         160 :                 break;
     886          50 :             case HEAPTUPLE_DELETE_IN_PROGRESS:
     887             : 
     888             :                 /*
     889             :                  * Similar situation to INSERT_IN_PROGRESS case.
     890             :                  */
     891          50 :                 if (!is_system_catalog &&
     892          30 :                     !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tuple->t_data)))
     893           0 :                     elog(WARNING, "concurrent delete in progress within table \"%s\"",
     894             :                          RelationGetRelationName(OldHeap));
     895             :                 /* treat as recently dead */
     896          50 :                 *tups_recently_dead += 1;
     897          50 :                 isdead = false;
     898          50 :                 break;
     899           0 :             default:
     900           0 :                 elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
     901             :                 isdead = false; /* keep compiler quiet */
     902             :                 break;
     903             :         }
     904             : 
     905      761470 :         LockBuffer(buf, BUFFER_LOCK_UNLOCK);
     906             : 
     907      761470 :         if (isdead)
     908             :         {
     909       33146 :             *tups_vacuumed += 1;
     910             :             /* heap rewrite module still needs to see it... */
     911       33146 :             if (rewrite_heap_dead_tuple(rwstate, tuple))
     912             :             {
     913             :                 /* A previous recently-dead tuple is now known dead */
     914           0 :                 *tups_vacuumed += 1;
     915           0 :                 *tups_recently_dead -= 1;
     916             :             }
     917       33146 :             continue;
     918             :         }
     919             : 
     920      728324 :         *num_tuples += 1;
     921      728324 :         if (tuplesort != NULL)
     922             :         {
     923      547414 :             tuplesort_putheaptuple(tuplesort, tuple);
     924             : 
     925             :             /*
     926             :              * In scan-and-sort mode, report increase in number of tuples
     927             :              * scanned
     928             :              */
     929      547414 :             pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_TUPLES_SCANNED,
     930      547414 :                                          *num_tuples);
     931             :         }
     932             :         else
     933             :         {
     934      180910 :             const int   ct_index[] = {
     935             :                 PROGRESS_CLUSTER_HEAP_TUPLES_SCANNED,
     936             :                 PROGRESS_CLUSTER_HEAP_TUPLES_WRITTEN
     937             :             };
     938             :             int64       ct_val[2];
     939             : 
     940      180910 :             reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
     941             :                                      values, isnull, rwstate);
     942             : 
     943             :             /*
     944             :              * In indexscan mode and also VACUUM FULL, report increase in
     945             :              * number of tuples scanned and written
     946             :              */
     947      180910 :             ct_val[0] = *num_tuples;
     948      180910 :             ct_val[1] = *num_tuples;
     949      180910 :             pgstat_progress_update_multi_param(2, ct_index, ct_val);
     950             :         }
     951             :     }
     952             : 
     953         568 :     if (indexScan != NULL)
     954          78 :         index_endscan(indexScan);
     955         568 :     if (tableScan != NULL)
     956         490 :         table_endscan(tableScan);
     957         568 :     if (slot)
     958         568 :         ExecDropSingleTupleTableSlot(slot);
     959             : 
     960             :     /*
     961             :      * In scan-and-sort mode, complete the sort, then read out all live tuples
     962             :      * from the tuplestore and write them to the new relation.
     963             :      */
     964         568 :     if (tuplesort != NULL)
     965             :     {
     966         110 :         double      n_tuples = 0;
     967             : 
     968             :         /* Report that we are now sorting tuples */
     969         110 :         pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
     970             :                                      PROGRESS_CLUSTER_PHASE_SORT_TUPLES);
     971             : 
     972         110 :         tuplesort_performsort(tuplesort);
     973             : 
     974             :         /* Report that we are now writing new heap */
     975         110 :         pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
     976             :                                      PROGRESS_CLUSTER_PHASE_WRITE_NEW_HEAP);
     977             : 
     978             :         for (;;)
     979      547414 :         {
     980             :             HeapTuple   tuple;
     981             : 
     982      547524 :             CHECK_FOR_INTERRUPTS();
     983             : 
     984      547524 :             tuple = tuplesort_getheaptuple(tuplesort, true);
     985      547524 :             if (tuple == NULL)
     986         110 :                 break;
     987             : 
     988      547414 :             n_tuples += 1;
     989      547414 :             reform_and_rewrite_tuple(tuple,
     990             :                                      OldHeap, NewHeap,
     991             :                                      values, isnull,
     992             :                                      rwstate);
     993             :             /* Report n_tuples */
     994      547414 :             pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_TUPLES_WRITTEN,
     995             :                                          n_tuples);
     996             :         }
     997             : 
     998         110 :         tuplesort_end(tuplesort);
     999             :     }
    1000             : 
    1001             :     /* Write out any remaining tuples, and fsync if needed */
    1002         568 :     end_heap_rewrite(rwstate);
    1003             : 
    1004             :     /* Clean up */
    1005         568 :     pfree(values);
    1006         568 :     pfree(isnull);
    1007         568 : }
    1008             : 
    1009             : /*
    1010             :  * Prepare to analyze the next block in the read stream.  Returns false if
    1011             :  * the stream is exhausted and true otherwise. The scan must have been started
    1012             :  * with SO_TYPE_ANALYZE option.
    1013             :  *
    1014             :  * This routine holds a buffer pin and lock on the heap page.  They are held
    1015             :  * until heapam_scan_analyze_next_tuple() returns false.  That is until all the
    1016             :  * items of the heap page are analyzed.
    1017             :  */
    1018             : static bool
    1019      168714 : heapam_scan_analyze_next_block(TableScanDesc scan, ReadStream *stream)
    1020             : {
    1021      168714 :     HeapScanDesc hscan = (HeapScanDesc) scan;
    1022             : 
    1023             :     /*
    1024             :      * We must maintain a pin on the target page's buffer to ensure that
    1025             :      * concurrent activity - e.g. HOT pruning - doesn't delete tuples out from
    1026             :      * under us.  It comes from the stream already pinned.   We also choose to
    1027             :      * hold sharelock on the buffer throughout --- we could release and
    1028             :      * re-acquire sharelock for each tuple, but since we aren't doing much
    1029             :      * work per tuple, the extra lock traffic is probably better avoided.
    1030             :      */
    1031      168714 :     hscan->rs_cbuf = read_stream_next_buffer(stream, NULL);
    1032      168714 :     if (!BufferIsValid(hscan->rs_cbuf))
    1033       18046 :         return false;
    1034             : 
    1035      150668 :     LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    1036             : 
    1037      150668 :     hscan->rs_cblock = BufferGetBlockNumber(hscan->rs_cbuf);
    1038      150668 :     hscan->rs_cindex = FirstOffsetNumber;
    1039      150668 :     return true;
    1040             : }
    1041             : 
    1042             : static bool
    1043    11476112 : heapam_scan_analyze_next_tuple(TableScanDesc scan, TransactionId OldestXmin,
    1044             :                                double *liverows, double *deadrows,
    1045             :                                TupleTableSlot *slot)
    1046             : {
    1047    11476112 :     HeapScanDesc hscan = (HeapScanDesc) scan;
    1048             :     Page        targpage;
    1049             :     OffsetNumber maxoffset;
    1050             :     BufferHeapTupleTableSlot *hslot;
    1051             : 
    1052             :     Assert(TTS_IS_BUFFERTUPLE(slot));
    1053             : 
    1054    11476112 :     hslot = (BufferHeapTupleTableSlot *) slot;
    1055    11476112 :     targpage = BufferGetPage(hscan->rs_cbuf);
    1056    11476112 :     maxoffset = PageGetMaxOffsetNumber(targpage);
    1057             : 
    1058             :     /* Inner loop over all tuples on the selected page */
    1059    12097740 :     for (; hscan->rs_cindex <= maxoffset; hscan->rs_cindex++)
    1060             :     {
    1061             :         ItemId      itemid;
    1062    11947072 :         HeapTuple   targtuple = &hslot->base.tupdata;
    1063    11947072 :         bool        sample_it = false;
    1064             : 
    1065    11947072 :         itemid = PageGetItemId(targpage, hscan->rs_cindex);
    1066             : 
    1067             :         /*
    1068             :          * We ignore unused and redirect line pointers.  DEAD line pointers
    1069             :          * should be counted as dead, because we need vacuum to run to get rid
    1070             :          * of them.  Note that this rule agrees with the way that
    1071             :          * heap_page_prune_and_freeze() counts things.
    1072             :          */
    1073    11947072 :         if (!ItemIdIsNormal(itemid))
    1074             :         {
    1075      427840 :             if (ItemIdIsDead(itemid))
    1076      139032 :                 *deadrows += 1;
    1077      427840 :             continue;
    1078             :         }
    1079             : 
    1080    11519232 :         ItemPointerSet(&targtuple->t_self, hscan->rs_cblock, hscan->rs_cindex);
    1081             : 
    1082    11519232 :         targtuple->t_tableOid = RelationGetRelid(scan->rs_rd);
    1083    11519232 :         targtuple->t_data = (HeapTupleHeader) PageGetItem(targpage, itemid);
    1084    11519232 :         targtuple->t_len = ItemIdGetLength(itemid);
    1085             : 
    1086    11519232 :         switch (HeapTupleSatisfiesVacuum(targtuple, OldestXmin,
    1087             :                                          hscan->rs_cbuf))
    1088             :         {
    1089    10865220 :             case HEAPTUPLE_LIVE:
    1090    10865220 :                 sample_it = true;
    1091    10865220 :                 *liverows += 1;
    1092    10865220 :                 break;
    1093             : 
    1094      191636 :             case HEAPTUPLE_DEAD:
    1095             :             case HEAPTUPLE_RECENTLY_DEAD:
    1096             :                 /* Count dead and recently-dead rows */
    1097      191636 :                 *deadrows += 1;
    1098      191636 :                 break;
    1099             : 
    1100      346726 :             case HEAPTUPLE_INSERT_IN_PROGRESS:
    1101             : 
    1102             :                 /*
    1103             :                  * Insert-in-progress rows are not counted.  We assume that
    1104             :                  * when the inserting transaction commits or aborts, it will
    1105             :                  * send a stats message to increment the proper count.  This
    1106             :                  * works right only if that transaction ends after we finish
    1107             :                  * analyzing the table; if things happen in the other order,
    1108             :                  * its stats update will be overwritten by ours.  However, the
    1109             :                  * error will be large only if the other transaction runs long
    1110             :                  * enough to insert many tuples, so assuming it will finish
    1111             :                  * after us is the safer option.
    1112             :                  *
    1113             :                  * A special case is that the inserting transaction might be
    1114             :                  * our own.  In this case we should count and sample the row,
    1115             :                  * to accommodate users who load a table and analyze it in one
    1116             :                  * transaction.  (pgstat_report_analyze has to adjust the
    1117             :                  * numbers we report to the cumulative stats system to make
    1118             :                  * this come out right.)
    1119             :                  */
    1120      346726 :                 if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(targtuple->t_data)))
    1121             :                 {
    1122      346290 :                     sample_it = true;
    1123      346290 :                     *liverows += 1;
    1124             :                 }
    1125      346726 :                 break;
    1126             : 
    1127      115650 :             case HEAPTUPLE_DELETE_IN_PROGRESS:
    1128             : 
    1129             :                 /*
    1130             :                  * We count and sample delete-in-progress rows the same as
    1131             :                  * live ones, so that the stats counters come out right if the
    1132             :                  * deleting transaction commits after us, per the same
    1133             :                  * reasoning given above.
    1134             :                  *
    1135             :                  * If the delete was done by our own transaction, however, we
    1136             :                  * must count the row as dead to make pgstat_report_analyze's
    1137             :                  * stats adjustments come out right.  (Note: this works out
    1138             :                  * properly when the row was both inserted and deleted in our
    1139             :                  * xact.)
    1140             :                  *
    1141             :                  * The net effect of these choices is that we act as though an
    1142             :                  * IN_PROGRESS transaction hasn't happened yet, except if it
    1143             :                  * is our own transaction, which we assume has happened.
    1144             :                  *
    1145             :                  * This approach ensures that we behave sanely if we see both
    1146             :                  * the pre-image and post-image rows for a row being updated
    1147             :                  * by a concurrent transaction: we will sample the pre-image
    1148             :                  * but not the post-image.  We also get sane results if the
    1149             :                  * concurrent transaction never commits.
    1150             :                  */
    1151      115650 :                 if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(targtuple->t_data)))
    1152        1716 :                     *deadrows += 1;
    1153             :                 else
    1154             :                 {
    1155      113934 :                     sample_it = true;
    1156      113934 :                     *liverows += 1;
    1157             :                 }
    1158      115650 :                 break;
    1159             : 
    1160           0 :             default:
    1161           0 :                 elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
    1162             :                 break;
    1163             :         }
    1164             : 
    1165    11519232 :         if (sample_it)
    1166             :         {
    1167    11325444 :             ExecStoreBufferHeapTuple(targtuple, slot, hscan->rs_cbuf);
    1168    11325444 :             hscan->rs_cindex++;
    1169             : 
    1170             :             /* note that we leave the buffer locked here! */
    1171    11325444 :             return true;
    1172             :         }
    1173             :     }
    1174             : 
    1175             :     /* Now release the lock and pin on the page */
    1176      150668 :     UnlockReleaseBuffer(hscan->rs_cbuf);
    1177      150668 :     hscan->rs_cbuf = InvalidBuffer;
    1178             : 
    1179             :     /* also prevent old slot contents from having pin on page */
    1180      150668 :     ExecClearTuple(slot);
    1181             : 
    1182      150668 :     return false;
    1183             : }
    1184             : 
    1185             : static double
    1186       58270 : heapam_index_build_range_scan(Relation heapRelation,
    1187             :                               Relation indexRelation,
    1188             :                               IndexInfo *indexInfo,
    1189             :                               bool allow_sync,
    1190             :                               bool anyvisible,
    1191             :                               bool progress,
    1192             :                               BlockNumber start_blockno,
    1193             :                               BlockNumber numblocks,
    1194             :                               IndexBuildCallback callback,
    1195             :                               void *callback_state,
    1196             :                               TableScanDesc scan)
    1197             : {
    1198             :     HeapScanDesc hscan;
    1199             :     bool        is_system_catalog;
    1200             :     bool        checking_uniqueness;
    1201             :     HeapTuple   heapTuple;
    1202             :     Datum       values[INDEX_MAX_KEYS];
    1203             :     bool        isnull[INDEX_MAX_KEYS];
    1204             :     double      reltuples;
    1205             :     ExprState  *predicate;
    1206             :     TupleTableSlot *slot;
    1207             :     EState     *estate;
    1208             :     ExprContext *econtext;
    1209             :     Snapshot    snapshot;
    1210       58270 :     bool        need_unregister_snapshot = false;
    1211             :     TransactionId OldestXmin;
    1212       58270 :     BlockNumber previous_blkno = InvalidBlockNumber;
    1213       58270 :     BlockNumber root_blkno = InvalidBlockNumber;
    1214             :     OffsetNumber root_offsets[MaxHeapTuplesPerPage];
    1215             : 
    1216             :     /*
    1217             :      * sanity checks
    1218             :      */
    1219             :     Assert(OidIsValid(indexRelation->rd_rel->relam));
    1220             : 
    1221             :     /* Remember if it's a system catalog */
    1222       58270 :     is_system_catalog = IsSystemRelation(heapRelation);
    1223             : 
    1224             :     /* See whether we're verifying uniqueness/exclusion properties */
    1225       73522 :     checking_uniqueness = (indexInfo->ii_Unique ||
    1226       15252 :                            indexInfo->ii_ExclusionOps != NULL);
    1227             : 
    1228             :     /*
    1229             :      * "Any visible" mode is not compatible with uniqueness checks; make sure
    1230             :      * only one of those is requested.
    1231             :      */
    1232             :     Assert(!(anyvisible && checking_uniqueness));
    1233             : 
    1234             :     /*
    1235             :      * Need an EState for evaluation of index expressions and partial-index
    1236             :      * predicates.  Also a slot to hold the current tuple.
    1237             :      */
    1238       58270 :     estate = CreateExecutorState();
    1239       58270 :     econtext = GetPerTupleExprContext(estate);
    1240       58270 :     slot = table_slot_create(heapRelation, NULL);
    1241             : 
    1242             :     /* Arrange for econtext's scan tuple to be the tuple under test */
    1243       58270 :     econtext->ecxt_scantuple = slot;
    1244             : 
    1245             :     /* Set up execution state for predicate, if any. */
    1246       58270 :     predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
    1247             : 
    1248             :     /*
    1249             :      * Prepare for scan of the base relation.  In a normal index build, we use
    1250             :      * SnapshotAny because we must retrieve all tuples and do our own time
    1251             :      * qual checks (because we have to index RECENTLY_DEAD tuples). In a
    1252             :      * concurrent build, or during bootstrap, we take a regular MVCC snapshot
    1253             :      * and index whatever's live according to that.
    1254             :      */
    1255       58270 :     OldestXmin = InvalidTransactionId;
    1256             : 
    1257             :     /* okay to ignore lazy VACUUMs here */
    1258       58270 :     if (!IsBootstrapProcessingMode() && !indexInfo->ii_Concurrent)
    1259       41144 :         OldestXmin = GetOldestNonRemovableTransactionId(heapRelation);
    1260             : 
    1261       58270 :     if (!scan)
    1262             :     {
    1263             :         /*
    1264             :          * Serial index build.
    1265             :          *
    1266             :          * Must begin our own heap scan in this case.  We may also need to
    1267             :          * register a snapshot whose lifetime is under our direct control.
    1268             :          */
    1269       57796 :         if (!TransactionIdIsValid(OldestXmin))
    1270             :         {
    1271       16980 :             snapshot = RegisterSnapshot(GetTransactionSnapshot());
    1272       16980 :             need_unregister_snapshot = true;
    1273             :         }
    1274             :         else
    1275       40816 :             snapshot = SnapshotAny;
    1276             : 
    1277       57796 :         scan = table_beginscan_strat(heapRelation,  /* relation */
    1278             :                                      snapshot,  /* snapshot */
    1279             :                                      0, /* number of keys */
    1280             :                                      NULL,  /* scan key */
    1281             :                                      true,  /* buffer access strategy OK */
    1282             :                                      allow_sync);   /* syncscan OK? */
    1283             :     }
    1284             :     else
    1285             :     {
    1286             :         /*
    1287             :          * Parallel index build.
    1288             :          *
    1289             :          * Parallel case never registers/unregisters own snapshot.  Snapshot
    1290             :          * is taken from parallel heap scan, and is SnapshotAny or an MVCC
    1291             :          * snapshot, based on same criteria as serial case.
    1292             :          */
    1293             :         Assert(!IsBootstrapProcessingMode());
    1294             :         Assert(allow_sync);
    1295         474 :         snapshot = scan->rs_snapshot;
    1296             :     }
    1297             : 
    1298       58270 :     hscan = (HeapScanDesc) scan;
    1299             : 
    1300             :     /*
    1301             :      * Must have called GetOldestNonRemovableTransactionId() if using
    1302             :      * SnapshotAny.  Shouldn't have for an MVCC snapshot. (It's especially
    1303             :      * worth checking this for parallel builds, since ambuild routines that
    1304             :      * support parallel builds must work these details out for themselves.)
    1305             :      */
    1306             :     Assert(snapshot == SnapshotAny || IsMVCCSnapshot(snapshot));
    1307             :     Assert(snapshot == SnapshotAny ? TransactionIdIsValid(OldestXmin) :
    1308             :            !TransactionIdIsValid(OldestXmin));
    1309             :     Assert(snapshot == SnapshotAny || !anyvisible);
    1310             : 
    1311             :     /* Publish number of blocks to scan */
    1312       58270 :     if (progress)
    1313             :     {
    1314             :         BlockNumber nblocks;
    1315             : 
    1316       55022 :         if (hscan->rs_base.rs_parallel != NULL)
    1317             :         {
    1318             :             ParallelBlockTableScanDesc pbscan;
    1319             : 
    1320         174 :             pbscan = (ParallelBlockTableScanDesc) hscan->rs_base.rs_parallel;
    1321         174 :             nblocks = pbscan->phs_nblocks;
    1322             :         }
    1323             :         else
    1324       54848 :             nblocks = hscan->rs_nblocks;
    1325             : 
    1326       55022 :         pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_TOTAL,
    1327             :                                      nblocks);
    1328             :     }
    1329             : 
    1330             :     /* set our scan endpoints */
    1331       58270 :     if (!allow_sync)
    1332        3728 :         heap_setscanlimits(scan, start_blockno, numblocks);
    1333             :     else
    1334             :     {
    1335             :         /* syncscan can only be requested on whole relation */
    1336             :         Assert(start_blockno == 0);
    1337             :         Assert(numblocks == InvalidBlockNumber);
    1338             :     }
    1339             : 
    1340       58270 :     reltuples = 0;
    1341             : 
    1342             :     /*
    1343             :      * Scan all tuples in the base relation.
    1344             :      */
    1345    17747470 :     while ((heapTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    1346             :     {
    1347             :         bool        tupleIsAlive;
    1348             : 
    1349    17689212 :         CHECK_FOR_INTERRUPTS();
    1350             : 
    1351             :         /* Report scan progress, if asked to. */
    1352    17689212 :         if (progress)
    1353             :         {
    1354    15022672 :             BlockNumber blocks_done = heapam_scan_get_blocks_done(hscan);
    1355             : 
    1356    15022672 :             if (blocks_done != previous_blkno)
    1357             :             {
    1358      194678 :                 pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
    1359             :                                              blocks_done);
    1360      194678 :                 previous_blkno = blocks_done;
    1361             :             }
    1362             :         }
    1363             : 
    1364             :         /*
    1365             :          * When dealing with a HOT-chain of updated tuples, we want to index
    1366             :          * the values of the live tuple (if any), but index it under the TID
    1367             :          * of the chain's root tuple.  This approach is necessary to preserve
    1368             :          * the HOT-chain structure in the heap. So we need to be able to find
    1369             :          * the root item offset for every tuple that's in a HOT-chain.  When
    1370             :          * first reaching a new page of the relation, call
    1371             :          * heap_get_root_tuples() to build a map of root item offsets on the
    1372             :          * page.
    1373             :          *
    1374             :          * It might look unsafe to use this information across buffer
    1375             :          * lock/unlock.  However, we hold ShareLock on the table so no
    1376             :          * ordinary insert/update/delete should occur; and we hold pin on the
    1377             :          * buffer continuously while visiting the page, so no pruning
    1378             :          * operation can occur either.
    1379             :          *
    1380             :          * In cases with only ShareUpdateExclusiveLock on the table, it's
    1381             :          * possible for some HOT tuples to appear that we didn't know about
    1382             :          * when we first read the page.  To handle that case, we re-obtain the
    1383             :          * list of root offsets when a HOT tuple points to a root item that we
    1384             :          * don't know about.
    1385             :          *
    1386             :          * Also, although our opinions about tuple liveness could change while
    1387             :          * we scan the page (due to concurrent transaction commits/aborts),
    1388             :          * the chain root locations won't, so this info doesn't need to be
    1389             :          * rebuilt after waiting for another transaction.
    1390             :          *
    1391             :          * Note the implied assumption that there is no more than one live
    1392             :          * tuple per HOT-chain --- else we could create more than one index
    1393             :          * entry pointing to the same root tuple.
    1394             :          */
    1395    17689212 :         if (hscan->rs_cblock != root_blkno)
    1396             :         {
    1397      221140 :             Page        page = BufferGetPage(hscan->rs_cbuf);
    1398             : 
    1399      221140 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    1400      221140 :             heap_get_root_tuples(page, root_offsets);
    1401      221140 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1402             : 
    1403      221140 :             root_blkno = hscan->rs_cblock;
    1404             :         }
    1405             : 
    1406    17689212 :         if (snapshot == SnapshotAny)
    1407             :         {
    1408             :             /* do our own time qual check */
    1409             :             bool        indexIt;
    1410             :             TransactionId xwait;
    1411             : 
    1412    14005930 :     recheck:
    1413             : 
    1414             :             /*
    1415             :              * We could possibly get away with not locking the buffer here,
    1416             :              * since caller should hold ShareLock on the relation, but let's
    1417             :              * be conservative about it.  (This remark is still correct even
    1418             :              * with HOT-pruning: our pin on the buffer prevents pruning.)
    1419             :              */
    1420    14005930 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    1421             : 
    1422             :             /*
    1423             :              * The criteria for counting a tuple as live in this block need to
    1424             :              * match what analyze.c's heapam_scan_analyze_next_tuple() does,
    1425             :              * otherwise CREATE INDEX and ANALYZE may produce wildly different
    1426             :              * reltuples values, e.g. when there are many recently-dead
    1427             :              * tuples.
    1428             :              */
    1429    14005930 :             switch (HeapTupleSatisfiesVacuum(heapTuple, OldestXmin,
    1430             :                                              hscan->rs_cbuf))
    1431             :             {
    1432       32146 :                 case HEAPTUPLE_DEAD:
    1433             :                     /* Definitely dead, we can ignore it */
    1434       32146 :                     indexIt = false;
    1435       32146 :                     tupleIsAlive = false;
    1436       32146 :                     break;
    1437    10224414 :                 case HEAPTUPLE_LIVE:
    1438             :                     /* Normal case, index and unique-check it */
    1439    10224414 :                     indexIt = true;
    1440    10224414 :                     tupleIsAlive = true;
    1441             :                     /* Count it as live, too */
    1442    10224414 :                     reltuples += 1;
    1443    10224414 :                     break;
    1444      202152 :                 case HEAPTUPLE_RECENTLY_DEAD:
    1445             : 
    1446             :                     /*
    1447             :                      * If tuple is recently deleted then we must index it
    1448             :                      * anyway to preserve MVCC semantics.  (Pre-existing
    1449             :                      * transactions could try to use the index after we finish
    1450             :                      * building it, and may need to see such tuples.)
    1451             :                      *
    1452             :                      * However, if it was HOT-updated then we must only index
    1453             :                      * the live tuple at the end of the HOT-chain.  Since this
    1454             :                      * breaks semantics for pre-existing snapshots, mark the
    1455             :                      * index as unusable for them.
    1456             :                      *
    1457             :                      * We don't count recently-dead tuples in reltuples, even
    1458             :                      * if we index them; see heapam_scan_analyze_next_tuple().
    1459             :                      */
    1460      202152 :                     if (HeapTupleIsHotUpdated(heapTuple))
    1461             :                     {
    1462         226 :                         indexIt = false;
    1463             :                         /* mark the index as unsafe for old snapshots */
    1464         226 :                         indexInfo->ii_BrokenHotChain = true;
    1465             :                     }
    1466             :                     else
    1467      201926 :                         indexIt = true;
    1468             :                     /* In any case, exclude the tuple from unique-checking */
    1469      202152 :                     tupleIsAlive = false;
    1470      202152 :                     break;
    1471     3547128 :                 case HEAPTUPLE_INSERT_IN_PROGRESS:
    1472             : 
    1473             :                     /*
    1474             :                      * In "anyvisible" mode, this tuple is visible and we
    1475             :                      * don't need any further checks.
    1476             :                      */
    1477     3547128 :                     if (anyvisible)
    1478             :                     {
    1479       61472 :                         indexIt = true;
    1480       61472 :                         tupleIsAlive = true;
    1481       61472 :                         reltuples += 1;
    1482       61472 :                         break;
    1483             :                     }
    1484             : 
    1485             :                     /*
    1486             :                      * Since caller should hold ShareLock or better, normally
    1487             :                      * the only way to see this is if it was inserted earlier
    1488             :                      * in our own transaction.  However, it can happen in
    1489             :                      * system catalogs, since we tend to release write lock
    1490             :                      * before commit there.  Give a warning if neither case
    1491             :                      * applies.
    1492             :                      */
    1493     3485656 :                     xwait = HeapTupleHeaderGetXmin(heapTuple->t_data);
    1494     3485656 :                     if (!TransactionIdIsCurrentTransactionId(xwait))
    1495             :                     {
    1496          30 :                         if (!is_system_catalog)
    1497           0 :                             elog(WARNING, "concurrent insert in progress within table \"%s\"",
    1498             :                                  RelationGetRelationName(heapRelation));
    1499             : 
    1500             :                         /*
    1501             :                          * If we are performing uniqueness checks, indexing
    1502             :                          * such a tuple could lead to a bogus uniqueness
    1503             :                          * failure.  In that case we wait for the inserting
    1504             :                          * transaction to finish and check again.
    1505             :                          */
    1506          30 :                         if (checking_uniqueness)
    1507             :                         {
    1508             :                             /*
    1509             :                              * Must drop the lock on the buffer before we wait
    1510             :                              */
    1511           0 :                             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1512           0 :                             XactLockTableWait(xwait, heapRelation,
    1513           0 :                                               &heapTuple->t_self,
    1514             :                                               XLTW_InsertIndexUnique);
    1515           0 :                             CHECK_FOR_INTERRUPTS();
    1516           0 :                             goto recheck;
    1517             :                         }
    1518             :                     }
    1519             :                     else
    1520             :                     {
    1521             :                         /*
    1522             :                          * For consistency with
    1523             :                          * heapam_scan_analyze_next_tuple(), count
    1524             :                          * HEAPTUPLE_INSERT_IN_PROGRESS tuples as live only
    1525             :                          * when inserted by our own transaction.
    1526             :                          */
    1527     3485626 :                         reltuples += 1;
    1528             :                     }
    1529             : 
    1530             :                     /*
    1531             :                      * We must index such tuples, since if the index build
    1532             :                      * commits then they're good.
    1533             :                      */
    1534     3485656 :                     indexIt = true;
    1535     3485656 :                     tupleIsAlive = true;
    1536     3485656 :                     break;
    1537          90 :                 case HEAPTUPLE_DELETE_IN_PROGRESS:
    1538             : 
    1539             :                     /*
    1540             :                      * As with INSERT_IN_PROGRESS case, this is unexpected
    1541             :                      * unless it's our own deletion or a system catalog; but
    1542             :                      * in anyvisible mode, this tuple is visible.
    1543             :                      */
    1544          90 :                     if (anyvisible)
    1545             :                     {
    1546           0 :                         indexIt = true;
    1547           0 :                         tupleIsAlive = false;
    1548           0 :                         reltuples += 1;
    1549           0 :                         break;
    1550             :                     }
    1551             : 
    1552          90 :                     xwait = HeapTupleHeaderGetUpdateXid(heapTuple->t_data);
    1553          90 :                     if (!TransactionIdIsCurrentTransactionId(xwait))
    1554             :                     {
    1555          12 :                         if (!is_system_catalog)
    1556           0 :                             elog(WARNING, "concurrent delete in progress within table \"%s\"",
    1557             :                                  RelationGetRelationName(heapRelation));
    1558             : 
    1559             :                         /*
    1560             :                          * If we are performing uniqueness checks, assuming
    1561             :                          * the tuple is dead could lead to missing a
    1562             :                          * uniqueness violation.  In that case we wait for the
    1563             :                          * deleting transaction to finish and check again.
    1564             :                          *
    1565             :                          * Also, if it's a HOT-updated tuple, we should not
    1566             :                          * index it but rather the live tuple at the end of
    1567             :                          * the HOT-chain.  However, the deleting transaction
    1568             :                          * could abort, possibly leaving this tuple as live
    1569             :                          * after all, in which case it has to be indexed. The
    1570             :                          * only way to know what to do is to wait for the
    1571             :                          * deleting transaction to finish and check again.
    1572             :                          */
    1573          24 :                         if (checking_uniqueness ||
    1574          12 :                             HeapTupleIsHotUpdated(heapTuple))
    1575             :                         {
    1576             :                             /*
    1577             :                              * Must drop the lock on the buffer before we wait
    1578             :                              */
    1579           0 :                             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1580           0 :                             XactLockTableWait(xwait, heapRelation,
    1581           0 :                                               &heapTuple->t_self,
    1582             :                                               XLTW_InsertIndexUnique);
    1583           0 :                             CHECK_FOR_INTERRUPTS();
    1584           0 :                             goto recheck;
    1585             :                         }
    1586             : 
    1587             :                         /*
    1588             :                          * Otherwise index it but don't check for uniqueness,
    1589             :                          * the same as a RECENTLY_DEAD tuple.
    1590             :                          */
    1591          12 :                         indexIt = true;
    1592             : 
    1593             :                         /*
    1594             :                          * Count HEAPTUPLE_DELETE_IN_PROGRESS tuples as live,
    1595             :                          * if they were not deleted by the current
    1596             :                          * transaction.  That's what
    1597             :                          * heapam_scan_analyze_next_tuple() does, and we want
    1598             :                          * the behavior to be consistent.
    1599             :                          */
    1600          12 :                         reltuples += 1;
    1601             :                     }
    1602          78 :                     else if (HeapTupleIsHotUpdated(heapTuple))
    1603             :                     {
    1604             :                         /*
    1605             :                          * It's a HOT-updated tuple deleted by our own xact.
    1606             :                          * We can assume the deletion will commit (else the
    1607             :                          * index contents don't matter), so treat the same as
    1608             :                          * RECENTLY_DEAD HOT-updated tuples.
    1609             :                          */
    1610           0 :                         indexIt = false;
    1611             :                         /* mark the index as unsafe for old snapshots */
    1612           0 :                         indexInfo->ii_BrokenHotChain = true;
    1613             :                     }
    1614             :                     else
    1615             :                     {
    1616             :                         /*
    1617             :                          * It's a regular tuple deleted by our own xact. Index
    1618             :                          * it, but don't check for uniqueness nor count in
    1619             :                          * reltuples, the same as a RECENTLY_DEAD tuple.
    1620             :                          */
    1621          78 :                         indexIt = true;
    1622             :                     }
    1623             :                     /* In any case, exclude the tuple from unique-checking */
    1624          90 :                     tupleIsAlive = false;
    1625          90 :                     break;
    1626           0 :                 default:
    1627           0 :                     elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
    1628             :                     indexIt = tupleIsAlive = false; /* keep compiler quiet */
    1629             :                     break;
    1630             :             }
    1631             : 
    1632    14005930 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1633             : 
    1634    14005930 :             if (!indexIt)
    1635       32372 :                 continue;
    1636             :         }
    1637             :         else
    1638             :         {
    1639             :             /* heap_getnext did the time qual check */
    1640     3683282 :             tupleIsAlive = true;
    1641     3683282 :             reltuples += 1;
    1642             :         }
    1643             : 
    1644    17656840 :         MemoryContextReset(econtext->ecxt_per_tuple_memory);
    1645             : 
    1646             :         /* Set up for predicate or expression evaluation */
    1647    17656840 :         ExecStoreBufferHeapTuple(heapTuple, slot, hscan->rs_cbuf);
    1648             : 
    1649             :         /*
    1650             :          * In a partial index, discard tuples that don't satisfy the
    1651             :          * predicate.
    1652             :          */
    1653    17656840 :         if (predicate != NULL)
    1654             :         {
    1655      204570 :             if (!ExecQual(predicate, econtext))
    1656      109674 :                 continue;
    1657             :         }
    1658             : 
    1659             :         /*
    1660             :          * For the current heap tuple, extract all the attributes we use in
    1661             :          * this index, and note which are null.  This also performs evaluation
    1662             :          * of any expressions needed.
    1663             :          */
    1664    17547166 :         FormIndexDatum(indexInfo,
    1665             :                        slot,
    1666             :                        estate,
    1667             :                        values,
    1668             :                        isnull);
    1669             : 
    1670             :         /*
    1671             :          * You'd think we should go ahead and build the index tuple here, but
    1672             :          * some index AMs want to do further processing on the data first.  So
    1673             :          * pass the values[] and isnull[] arrays, instead.
    1674             :          */
    1675             : 
    1676    17547154 :         if (HeapTupleIsHeapOnly(heapTuple))
    1677             :         {
    1678             :             /*
    1679             :              * For a heap-only tuple, pretend its TID is that of the root. See
    1680             :              * src/backend/access/heap/README.HOT for discussion.
    1681             :              */
    1682             :             ItemPointerData tid;
    1683             :             OffsetNumber offnum;
    1684             : 
    1685        8682 :             offnum = ItemPointerGetOffsetNumber(&heapTuple->t_self);
    1686             : 
    1687             :             /*
    1688             :              * If a HOT tuple points to a root that we don't know about,
    1689             :              * obtain root items afresh.  If that still fails, report it as
    1690             :              * corruption.
    1691             :              */
    1692        8682 :             if (root_offsets[offnum - 1] == InvalidOffsetNumber)
    1693             :             {
    1694           0 :                 Page        page = BufferGetPage(hscan->rs_cbuf);
    1695             : 
    1696           0 :                 LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    1697           0 :                 heap_get_root_tuples(page, root_offsets);
    1698           0 :                 LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1699             :             }
    1700             : 
    1701        8682 :             if (!OffsetNumberIsValid(root_offsets[offnum - 1]))
    1702           0 :                 ereport(ERROR,
    1703             :                         (errcode(ERRCODE_DATA_CORRUPTED),
    1704             :                          errmsg_internal("failed to find parent tuple for heap-only tuple at (%u,%u) in table \"%s\"",
    1705             :                                          ItemPointerGetBlockNumber(&heapTuple->t_self),
    1706             :                                          offnum,
    1707             :                                          RelationGetRelationName(heapRelation))));
    1708             : 
    1709        8682 :             ItemPointerSet(&tid, ItemPointerGetBlockNumber(&heapTuple->t_self),
    1710        8682 :                            root_offsets[offnum - 1]);
    1711             : 
    1712             :             /* Call the AM's callback routine to process the tuple */
    1713        8682 :             callback(indexRelation, &tid, values, isnull, tupleIsAlive,
    1714             :                      callback_state);
    1715             :         }
    1716             :         else
    1717             :         {
    1718             :             /* Call the AM's callback routine to process the tuple */
    1719    17538472 :             callback(indexRelation, &heapTuple->t_self, values, isnull,
    1720             :                      tupleIsAlive, callback_state);
    1721             :         }
    1722             :     }
    1723             : 
    1724             :     /* Report scan progress one last time. */
    1725       58258 :     if (progress)
    1726             :     {
    1727             :         BlockNumber blks_done;
    1728             : 
    1729       55010 :         if (hscan->rs_base.rs_parallel != NULL)
    1730             :         {
    1731             :             ParallelBlockTableScanDesc pbscan;
    1732             : 
    1733         174 :             pbscan = (ParallelBlockTableScanDesc) hscan->rs_base.rs_parallel;
    1734         174 :             blks_done = pbscan->phs_nblocks;
    1735             :         }
    1736             :         else
    1737       54836 :             blks_done = hscan->rs_nblocks;
    1738             : 
    1739       55010 :         pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
    1740             :                                      blks_done);
    1741             :     }
    1742             : 
    1743       58258 :     table_endscan(scan);
    1744             : 
    1745             :     /* we can now forget our snapshot, if set and registered by us */
    1746       58258 :     if (need_unregister_snapshot)
    1747       16974 :         UnregisterSnapshot(snapshot);
    1748             : 
    1749       58258 :     ExecDropSingleTupleTableSlot(slot);
    1750             : 
    1751       58258 :     FreeExecutorState(estate);
    1752             : 
    1753             :     /* These may have been pointing to the now-gone estate */
    1754       58258 :     indexInfo->ii_ExpressionsState = NIL;
    1755       58258 :     indexInfo->ii_PredicateState = NULL;
    1756             : 
    1757       58258 :     return reltuples;
    1758             : }
    1759             : 
    1760             : static void
    1761         738 : heapam_index_validate_scan(Relation heapRelation,
    1762             :                            Relation indexRelation,
    1763             :                            IndexInfo *indexInfo,
    1764             :                            Snapshot snapshot,
    1765             :                            ValidateIndexState *state)
    1766             : {
    1767             :     TableScanDesc scan;
    1768             :     HeapScanDesc hscan;
    1769             :     HeapTuple   heapTuple;
    1770             :     Datum       values[INDEX_MAX_KEYS];
    1771             :     bool        isnull[INDEX_MAX_KEYS];
    1772             :     ExprState  *predicate;
    1773             :     TupleTableSlot *slot;
    1774             :     EState     *estate;
    1775             :     ExprContext *econtext;
    1776         738 :     BlockNumber root_blkno = InvalidBlockNumber;
    1777             :     OffsetNumber root_offsets[MaxHeapTuplesPerPage];
    1778             :     bool        in_index[MaxHeapTuplesPerPage];
    1779         738 :     BlockNumber previous_blkno = InvalidBlockNumber;
    1780             : 
    1781             :     /* state variables for the merge */
    1782         738 :     ItemPointer indexcursor = NULL;
    1783             :     ItemPointerData decoded;
    1784         738 :     bool        tuplesort_empty = false;
    1785             : 
    1786             :     /*
    1787             :      * sanity checks
    1788             :      */
    1789             :     Assert(OidIsValid(indexRelation->rd_rel->relam));
    1790             : 
    1791             :     /*
    1792             :      * Need an EState for evaluation of index expressions and partial-index
    1793             :      * predicates.  Also a slot to hold the current tuple.
    1794             :      */
    1795         738 :     estate = CreateExecutorState();
    1796         738 :     econtext = GetPerTupleExprContext(estate);
    1797         738 :     slot = MakeSingleTupleTableSlot(RelationGetDescr(heapRelation),
    1798             :                                     &TTSOpsHeapTuple);
    1799             : 
    1800             :     /* Arrange for econtext's scan tuple to be the tuple under test */
    1801         738 :     econtext->ecxt_scantuple = slot;
    1802             : 
    1803             :     /* Set up execution state for predicate, if any. */
    1804         738 :     predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
    1805             : 
    1806             :     /*
    1807             :      * Prepare for scan of the base relation.  We need just those tuples
    1808             :      * satisfying the passed-in reference snapshot.  We must disable syncscan
    1809             :      * here, because it's critical that we read from block zero forward to
    1810             :      * match the sorted TIDs.
    1811             :      */
    1812         738 :     scan = table_beginscan_strat(heapRelation,  /* relation */
    1813             :                                  snapshot,  /* snapshot */
    1814             :                                  0, /* number of keys */
    1815             :                                  NULL,  /* scan key */
    1816             :                                  true,  /* buffer access strategy OK */
    1817             :                                  false);    /* syncscan not OK */
    1818         738 :     hscan = (HeapScanDesc) scan;
    1819             : 
    1820         738 :     pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_TOTAL,
    1821         738 :                                  hscan->rs_nblocks);
    1822             : 
    1823             :     /*
    1824             :      * Scan all tuples matching the snapshot.
    1825             :      */
    1826      250458 :     while ((heapTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    1827             :     {
    1828      249720 :         ItemPointer heapcursor = &heapTuple->t_self;
    1829             :         ItemPointerData rootTuple;
    1830             :         OffsetNumber root_offnum;
    1831             : 
    1832      249720 :         CHECK_FOR_INTERRUPTS();
    1833             : 
    1834      249720 :         state->htups += 1;
    1835             : 
    1836      249720 :         if ((previous_blkno == InvalidBlockNumber) ||
    1837      249276 :             (hscan->rs_cblock != previous_blkno))
    1838             :         {
    1839        4722 :             pgstat_progress_update_param(PROGRESS_SCAN_BLOCKS_DONE,
    1840        4722 :                                          hscan->rs_cblock);
    1841        4722 :             previous_blkno = hscan->rs_cblock;
    1842             :         }
    1843             : 
    1844             :         /*
    1845             :          * As commented in table_index_build_scan, we should index heap-only
    1846             :          * tuples under the TIDs of their root tuples; so when we advance onto
    1847             :          * a new heap page, build a map of root item offsets on the page.
    1848             :          *
    1849             :          * This complicates merging against the tuplesort output: we will
    1850             :          * visit the live tuples in order by their offsets, but the root
    1851             :          * offsets that we need to compare against the index contents might be
    1852             :          * ordered differently.  So we might have to "look back" within the
    1853             :          * tuplesort output, but only within the current page.  We handle that
    1854             :          * by keeping a bool array in_index[] showing all the
    1855             :          * already-passed-over tuplesort output TIDs of the current page. We
    1856             :          * clear that array here, when advancing onto a new heap page.
    1857             :          */
    1858      249720 :         if (hscan->rs_cblock != root_blkno)
    1859             :         {
    1860        4722 :             Page        page = BufferGetPage(hscan->rs_cbuf);
    1861             : 
    1862        4722 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    1863        4722 :             heap_get_root_tuples(page, root_offsets);
    1864        4722 :             LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    1865             : 
    1866        4722 :             memset(in_index, 0, sizeof(in_index));
    1867             : 
    1868        4722 :             root_blkno = hscan->rs_cblock;
    1869             :         }
    1870             : 
    1871             :         /* Convert actual tuple TID to root TID */
    1872      249720 :         rootTuple = *heapcursor;
    1873      249720 :         root_offnum = ItemPointerGetOffsetNumber(heapcursor);
    1874             : 
    1875      249720 :         if (HeapTupleIsHeapOnly(heapTuple))
    1876             :         {
    1877          18 :             root_offnum = root_offsets[root_offnum - 1];
    1878          18 :             if (!OffsetNumberIsValid(root_offnum))
    1879           0 :                 ereport(ERROR,
    1880             :                         (errcode(ERRCODE_DATA_CORRUPTED),
    1881             :                          errmsg_internal("failed to find parent tuple for heap-only tuple at (%u,%u) in table \"%s\"",
    1882             :                                          ItemPointerGetBlockNumber(heapcursor),
    1883             :                                          ItemPointerGetOffsetNumber(heapcursor),
    1884             :                                          RelationGetRelationName(heapRelation))));
    1885          18 :             ItemPointerSetOffsetNumber(&rootTuple, root_offnum);
    1886             :         }
    1887             : 
    1888             :         /*
    1889             :          * "merge" by skipping through the index tuples until we find or pass
    1890             :          * the current root tuple.
    1891             :          */
    1892      558084 :         while (!tuplesort_empty &&
    1893      557582 :                (!indexcursor ||
    1894      557582 :                 ItemPointerCompare(indexcursor, &rootTuple) < 0))
    1895             :         {
    1896             :             Datum       ts_val;
    1897             :             bool        ts_isnull;
    1898             : 
    1899      308364 :             if (indexcursor)
    1900             :             {
    1901             :                 /*
    1902             :                  * Remember index items seen earlier on the current heap page
    1903             :                  */
    1904      307920 :                 if (ItemPointerGetBlockNumber(indexcursor) == root_blkno)
    1905      302134 :                     in_index[ItemPointerGetOffsetNumber(indexcursor) - 1] = true;
    1906             :             }
    1907             : 
    1908      308364 :             tuplesort_empty = !tuplesort_getdatum(state->tuplesort, true,
    1909             :                                                   false, &ts_val, &ts_isnull,
    1910      308364 :                                                   NULL);
    1911             :             Assert(tuplesort_empty || !ts_isnull);
    1912      308364 :             if (!tuplesort_empty)
    1913             :             {
    1914      308332 :                 itemptr_decode(&decoded, DatumGetInt64(ts_val));
    1915      308332 :                 indexcursor = &decoded;
    1916             :             }
    1917             :             else
    1918             :             {
    1919             :                 /* Be tidy */
    1920          32 :                 indexcursor = NULL;
    1921             :             }
    1922             :         }
    1923             : 
    1924             :         /*
    1925             :          * If the tuplesort has overshot *and* we didn't see a match earlier,
    1926             :          * then this tuple is missing from the index, so insert it.
    1927             :          */
    1928      499382 :         if ((tuplesort_empty ||
    1929      249662 :              ItemPointerCompare(indexcursor, &rootTuple) > 0) &&
    1930         148 :             !in_index[root_offnum - 1])
    1931             :         {
    1932         136 :             MemoryContextReset(econtext->ecxt_per_tuple_memory);
    1933             : 
    1934             :             /* Set up for predicate or expression evaluation */
    1935         136 :             ExecStoreHeapTuple(heapTuple, slot, false);
    1936             : 
    1937             :             /*
    1938             :              * In a partial index, discard tuples that don't satisfy the
    1939             :              * predicate.
    1940             :              */
    1941         136 :             if (predicate != NULL)
    1942             :             {
    1943          48 :                 if (!ExecQual(predicate, econtext))
    1944          48 :                     continue;
    1945             :             }
    1946             : 
    1947             :             /*
    1948             :              * For the current heap tuple, extract all the attributes we use
    1949             :              * in this index, and note which are null.  This also performs
    1950             :              * evaluation of any expressions needed.
    1951             :              */
    1952          88 :             FormIndexDatum(indexInfo,
    1953             :                            slot,
    1954             :                            estate,
    1955             :                            values,
    1956             :                            isnull);
    1957             : 
    1958             :             /*
    1959             :              * You'd think we should go ahead and build the index tuple here,
    1960             :              * but some index AMs want to do further processing on the data
    1961             :              * first. So pass the values[] and isnull[] arrays, instead.
    1962             :              */
    1963             : 
    1964             :             /*
    1965             :              * If the tuple is already committed dead, you might think we
    1966             :              * could suppress uniqueness checking, but this is no longer true
    1967             :              * in the presence of HOT, because the insert is actually a proxy
    1968             :              * for a uniqueness check on the whole HOT-chain.  That is, the
    1969             :              * tuple we have here could be dead because it was already
    1970             :              * HOT-updated, and if so the updating transaction will not have
    1971             :              * thought it should insert index entries.  The index AM will
    1972             :              * check the whole HOT-chain and correctly detect a conflict if
    1973             :              * there is one.
    1974             :              */
    1975             : 
    1976          88 :             index_insert(indexRelation,
    1977             :                          values,
    1978             :                          isnull,
    1979             :                          &rootTuple,
    1980             :                          heapRelation,
    1981          88 :                          indexInfo->ii_Unique ?
    1982             :                          UNIQUE_CHECK_YES : UNIQUE_CHECK_NO,
    1983             :                          false,
    1984             :                          indexInfo);
    1985             : 
    1986          88 :             state->tups_inserted += 1;
    1987             :         }
    1988             :     }
    1989             : 
    1990         738 :     table_endscan(scan);
    1991             : 
    1992         738 :     ExecDropSingleTupleTableSlot(slot);
    1993             : 
    1994         738 :     FreeExecutorState(estate);
    1995             : 
    1996             :     /* These may have been pointing to the now-gone estate */
    1997         738 :     indexInfo->ii_ExpressionsState = NIL;
    1998         738 :     indexInfo->ii_PredicateState = NULL;
    1999         738 : }
    2000             : 
    2001             : /*
    2002             :  * Return the number of blocks that have been read by this scan since
    2003             :  * starting.  This is meant for progress reporting rather than be fully
    2004             :  * accurate: in a parallel scan, workers can be concurrently reading blocks
    2005             :  * further ahead than what we report.
    2006             :  */
    2007             : static BlockNumber
    2008    15022672 : heapam_scan_get_blocks_done(HeapScanDesc hscan)
    2009             : {
    2010    15022672 :     ParallelBlockTableScanDesc bpscan = NULL;
    2011             :     BlockNumber startblock;
    2012             :     BlockNumber blocks_done;
    2013             : 
    2014    15022672 :     if (hscan->rs_base.rs_parallel != NULL)
    2015             :     {
    2016     2173778 :         bpscan = (ParallelBlockTableScanDesc) hscan->rs_base.rs_parallel;
    2017     2173778 :         startblock = bpscan->phs_startblock;
    2018             :     }
    2019             :     else
    2020    12848894 :         startblock = hscan->rs_startblock;
    2021             : 
    2022             :     /*
    2023             :      * Might have wrapped around the end of the relation, if startblock was
    2024             :      * not zero.
    2025             :      */
    2026    15022672 :     if (hscan->rs_cblock > startblock)
    2027    14447922 :         blocks_done = hscan->rs_cblock - startblock;
    2028             :     else
    2029             :     {
    2030             :         BlockNumber nblocks;
    2031             : 
    2032      574750 :         nblocks = bpscan != NULL ? bpscan->phs_nblocks : hscan->rs_nblocks;
    2033      574750 :         blocks_done = nblocks - startblock +
    2034      574750 :             hscan->rs_cblock;
    2035             :     }
    2036             : 
    2037    15022672 :     return blocks_done;
    2038             : }
    2039             : 
    2040             : 
    2041             : /* ------------------------------------------------------------------------
    2042             :  * Miscellaneous callbacks for the heap AM
    2043             :  * ------------------------------------------------------------------------
    2044             :  */
    2045             : 
    2046             : /*
    2047             :  * Check to see whether the table needs a TOAST table.  It does only if
    2048             :  * (1) there are any toastable attributes, and (2) the maximum length
    2049             :  * of a tuple could exceed TOAST_TUPLE_THRESHOLD.  (We don't want to
    2050             :  * create a toast table for something like "f1 varchar(20)".)
    2051             :  */
    2052             : static bool
    2053       46320 : heapam_relation_needs_toast_table(Relation rel)
    2054             : {
    2055       46320 :     int32       data_length = 0;
    2056       46320 :     bool        maxlength_unknown = false;
    2057       46320 :     bool        has_toastable_attrs = false;
    2058       46320 :     TupleDesc   tupdesc = rel->rd_att;
    2059             :     int32       tuple_length;
    2060             :     int         i;
    2061             : 
    2062      185036 :     for (i = 0; i < tupdesc->natts; i++)
    2063             :     {
    2064      138716 :         Form_pg_attribute att = TupleDescAttr(tupdesc, i);
    2065             : 
    2066      138716 :         if (att->attisdropped)
    2067        1122 :             continue;
    2068      137594 :         if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
    2069         866 :             continue;
    2070      136728 :         data_length = att_align_nominal(data_length, att->attalign);
    2071      136728 :         if (att->attlen > 0)
    2072             :         {
    2073             :             /* Fixed-length types are never toastable */
    2074      102044 :             data_length += att->attlen;
    2075             :         }
    2076             :         else
    2077             :         {
    2078       34684 :             int32       maxlen = type_maximum_size(att->atttypid,
    2079             :                                                    att->atttypmod);
    2080             : 
    2081       34684 :             if (maxlen < 0)
    2082       31514 :                 maxlength_unknown = true;
    2083             :             else
    2084        3170 :                 data_length += maxlen;
    2085       34684 :             if (att->attstorage != TYPSTORAGE_PLAIN)
    2086       33446 :                 has_toastable_attrs = true;
    2087             :         }
    2088             :     }
    2089       46320 :     if (!has_toastable_attrs)
    2090       26556 :         return false;           /* nothing to toast? */
    2091       19764 :     if (maxlength_unknown)
    2092       17414 :         return true;            /* any unlimited-length attrs? */
    2093        2350 :     tuple_length = MAXALIGN(SizeofHeapTupleHeader +
    2094        2350 :                             BITMAPLEN(tupdesc->natts)) +
    2095        2350 :         MAXALIGN(data_length);
    2096        2350 :     return (tuple_length > TOAST_TUPLE_THRESHOLD);
    2097             : }
    2098             : 
    2099             : /*
    2100             :  * TOAST tables for heap relations are just heap relations.
    2101             :  */
    2102             : static Oid
    2103       17974 : heapam_relation_toast_am(Relation rel)
    2104             : {
    2105       17974 :     return rel->rd_rel->relam;
    2106             : }
    2107             : 
    2108             : 
    2109             : /* ------------------------------------------------------------------------
    2110             :  * Planner related callbacks for the heap AM
    2111             :  * ------------------------------------------------------------------------
    2112             :  */
    2113             : 
    2114             : #define HEAP_OVERHEAD_BYTES_PER_TUPLE \
    2115             :     (MAXALIGN(SizeofHeapTupleHeader) + sizeof(ItemIdData))
    2116             : #define HEAP_USABLE_BYTES_PER_PAGE \
    2117             :     (BLCKSZ - SizeOfPageHeaderData)
    2118             : 
    2119             : static void
    2120      464296 : heapam_estimate_rel_size(Relation rel, int32 *attr_widths,
    2121             :                          BlockNumber *pages, double *tuples,
    2122             :                          double *allvisfrac)
    2123             : {
    2124      464296 :     table_block_relation_estimate_size(rel, attr_widths, pages,
    2125             :                                        tuples, allvisfrac,
    2126             :                                        HEAP_OVERHEAD_BYTES_PER_TUPLE,
    2127             :                                        HEAP_USABLE_BYTES_PER_PAGE);
    2128      464296 : }
    2129             : 
    2130             : 
    2131             : /* ------------------------------------------------------------------------
    2132             :  * Executor related callbacks for the heap AM
    2133             :  * ------------------------------------------------------------------------
    2134             :  */
    2135             : 
    2136             : static bool
    2137     6834706 : heapam_scan_bitmap_next_tuple(TableScanDesc scan,
    2138             :                               TupleTableSlot *slot,
    2139             :                               bool *recheck,
    2140             :                               uint64 *lossy_pages,
    2141             :                               uint64 *exact_pages)
    2142             : {
    2143     6834706 :     BitmapHeapScanDesc bscan = (BitmapHeapScanDesc) scan;
    2144     6834706 :     HeapScanDesc hscan = (HeapScanDesc) bscan;
    2145             :     OffsetNumber targoffset;
    2146             :     Page        page;
    2147             :     ItemId      lp;
    2148             : 
    2149             :     /*
    2150             :      * Out of range?  If so, nothing more to look at on this page
    2151             :      */
    2152     7240872 :     while (hscan->rs_cindex >= hscan->rs_ntuples)
    2153             :     {
    2154             :         /*
    2155             :          * Returns false if the bitmap is exhausted and there are no further
    2156             :          * blocks we need to scan.
    2157             :          */
    2158      432110 :         if (!BitmapHeapScanNextBlock(scan, recheck, lossy_pages, exact_pages))
    2159       25938 :             return false;
    2160             :     }
    2161             : 
    2162     6808762 :     targoffset = hscan->rs_vistuples[hscan->rs_cindex];
    2163     6808762 :     page = BufferGetPage(hscan->rs_cbuf);
    2164     6808762 :     lp = PageGetItemId(page, targoffset);
    2165             :     Assert(ItemIdIsNormal(lp));
    2166             : 
    2167     6808762 :     hscan->rs_ctup.t_data = (HeapTupleHeader) PageGetItem(page, lp);
    2168     6808762 :     hscan->rs_ctup.t_len = ItemIdGetLength(lp);
    2169     6808762 :     hscan->rs_ctup.t_tableOid = scan->rs_rd->rd_id;
    2170     6808762 :     ItemPointerSet(&hscan->rs_ctup.t_self, hscan->rs_cblock, targoffset);
    2171             : 
    2172     6808762 :     pgstat_count_heap_fetch(scan->rs_rd);
    2173             : 
    2174             :     /*
    2175             :      * Set up the result slot to point to this tuple.  Note that the slot
    2176             :      * acquires a pin on the buffer.
    2177             :      */
    2178     6808762 :     ExecStoreBufferHeapTuple(&hscan->rs_ctup,
    2179             :                              slot,
    2180             :                              hscan->rs_cbuf);
    2181             : 
    2182     6808762 :     hscan->rs_cindex++;
    2183             : 
    2184     6808762 :     return true;
    2185             : }
    2186             : 
    2187             : static bool
    2188       12912 : heapam_scan_sample_next_block(TableScanDesc scan, SampleScanState *scanstate)
    2189             : {
    2190       12912 :     HeapScanDesc hscan = (HeapScanDesc) scan;
    2191       12912 :     TsmRoutine *tsm = scanstate->tsmroutine;
    2192             :     BlockNumber blockno;
    2193             : 
    2194             :     /* return false immediately if relation is empty */
    2195       12912 :     if (hscan->rs_nblocks == 0)
    2196           0 :         return false;
    2197             : 
    2198             :     /* release previous scan buffer, if any */
    2199       12912 :     if (BufferIsValid(hscan->rs_cbuf))
    2200             :     {
    2201       12736 :         ReleaseBuffer(hscan->rs_cbuf);
    2202       12736 :         hscan->rs_cbuf = InvalidBuffer;
    2203             :     }
    2204             : 
    2205       12912 :     if (tsm->NextSampleBlock)
    2206        4446 :         blockno = tsm->NextSampleBlock(scanstate, hscan->rs_nblocks);
    2207             :     else
    2208             :     {
    2209             :         /* scanning table sequentially */
    2210             : 
    2211        8466 :         if (hscan->rs_cblock == InvalidBlockNumber)
    2212             :         {
    2213             :             Assert(!hscan->rs_inited);
    2214          78 :             blockno = hscan->rs_startblock;
    2215             :         }
    2216             :         else
    2217             :         {
    2218             :             Assert(hscan->rs_inited);
    2219             : 
    2220        8388 :             blockno = hscan->rs_cblock + 1;
    2221             : 
    2222        8388 :             if (blockno >= hscan->rs_nblocks)
    2223             :             {
    2224             :                 /* wrap to beginning of rel, might not have started at 0 */
    2225          78 :                 blockno = 0;
    2226             :             }
    2227             : 
    2228             :             /*
    2229             :              * Report our new scan position for synchronization purposes.
    2230             :              *
    2231             :              * Note: we do this before checking for end of scan so that the
    2232             :              * final state of the position hint is back at the start of the
    2233             :              * rel.  That's not strictly necessary, but otherwise when you run
    2234             :              * the same query multiple times the starting position would shift
    2235             :              * a little bit backwards on every invocation, which is confusing.
    2236             :              * We don't guarantee any specific ordering in general, though.
    2237             :              */
    2238        8388 :             if (scan->rs_flags & SO_ALLOW_SYNC)
    2239           0 :                 ss_report_location(scan->rs_rd, blockno);
    2240             : 
    2241        8388 :             if (blockno == hscan->rs_startblock)
    2242             :             {
    2243          78 :                 blockno = InvalidBlockNumber;
    2244             :             }
    2245             :         }
    2246             :     }
    2247             : 
    2248       12912 :     hscan->rs_cblock = blockno;
    2249             : 
    2250       12912 :     if (!BlockNumberIsValid(blockno))
    2251             :     {
    2252         170 :         hscan->rs_inited = false;
    2253         170 :         return false;
    2254             :     }
    2255             : 
    2256             :     Assert(hscan->rs_cblock < hscan->rs_nblocks);
    2257             : 
    2258             :     /*
    2259             :      * Be sure to check for interrupts at least once per page.  Checks at
    2260             :      * higher code levels won't be able to stop a sample scan that encounters
    2261             :      * many pages' worth of consecutive dead tuples.
    2262             :      */
    2263       12742 :     CHECK_FOR_INTERRUPTS();
    2264             : 
    2265             :     /* Read page using selected strategy */
    2266       12742 :     hscan->rs_cbuf = ReadBufferExtended(hscan->rs_base.rs_rd, MAIN_FORKNUM,
    2267             :                                         blockno, RBM_NORMAL, hscan->rs_strategy);
    2268             : 
    2269             :     /* in pagemode, prune the page and determine visible tuple offsets */
    2270       12742 :     if (hscan->rs_base.rs_flags & SO_ALLOW_PAGEMODE)
    2271        8554 :         heap_prepare_pagescan(scan);
    2272             : 
    2273       12742 :     hscan->rs_inited = true;
    2274       12742 :     return true;
    2275             : }
    2276             : 
    2277             : static bool
    2278      253896 : heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
    2279             :                               TupleTableSlot *slot)
    2280             : {
    2281      253896 :     HeapScanDesc hscan = (HeapScanDesc) scan;
    2282      253896 :     TsmRoutine *tsm = scanstate->tsmroutine;
    2283      253896 :     BlockNumber blockno = hscan->rs_cblock;
    2284      253896 :     bool        pagemode = (scan->rs_flags & SO_ALLOW_PAGEMODE) != 0;
    2285             : 
    2286             :     Page        page;
    2287             :     bool        all_visible;
    2288             :     OffsetNumber maxoffset;
    2289             : 
    2290             :     /*
    2291             :      * When not using pagemode, we must lock the buffer during tuple
    2292             :      * visibility checks.
    2293             :      */
    2294      253896 :     if (!pagemode)
    2295        4194 :         LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
    2296             : 
    2297      253896 :     page = BufferGetPage(hscan->rs_cbuf);
    2298      506688 :     all_visible = PageIsAllVisible(page) &&
    2299      252792 :         !scan->rs_snapshot->takenDuringRecovery;
    2300      253896 :     maxoffset = PageGetMaxOffsetNumber(page);
    2301             : 
    2302             :     for (;;)
    2303           0 :     {
    2304             :         OffsetNumber tupoffset;
    2305             : 
    2306      253896 :         CHECK_FOR_INTERRUPTS();
    2307             : 
    2308             :         /* Ask the tablesample method which tuples to check on this page. */
    2309      253896 :         tupoffset = tsm->NextSampleTuple(scanstate,
    2310             :                                          blockno,
    2311             :                                          maxoffset);
    2312             : 
    2313      253896 :         if (OffsetNumberIsValid(tupoffset))
    2314             :         {
    2315             :             ItemId      itemid;
    2316             :             bool        visible;
    2317      241160 :             HeapTuple   tuple = &(hscan->rs_ctup);
    2318             : 
    2319             :             /* Skip invalid tuple pointers. */
    2320      241160 :             itemid = PageGetItemId(page, tupoffset);
    2321      241160 :             if (!ItemIdIsNormal(itemid))
    2322           0 :                 continue;
    2323             : 
    2324      241160 :             tuple->t_data = (HeapTupleHeader) PageGetItem(page, itemid);
    2325      241160 :             tuple->t_len = ItemIdGetLength(itemid);
    2326      241160 :             ItemPointerSet(&(tuple->t_self), blockno, tupoffset);
    2327             : 
    2328             : 
    2329      241160 :             if (all_visible)
    2330      240348 :                 visible = true;
    2331             :             else
    2332         812 :                 visible = SampleHeapTupleVisible(scan, hscan->rs_cbuf,
    2333             :                                                  tuple, tupoffset);
    2334             : 
    2335             :             /* in pagemode, heap_prepare_pagescan did this for us */
    2336      241160 :             if (!pagemode)
    2337           6 :                 HeapCheckForSerializableConflictOut(visible, scan->rs_rd, tuple,
    2338             :                                                     hscan->rs_cbuf, scan->rs_snapshot);
    2339             : 
    2340             :             /* Try next tuple from same page. */
    2341      241160 :             if (!visible)
    2342           0 :                 continue;
    2343             : 
    2344             :             /* Found visible tuple, return it. */
    2345      241160 :             if (!pagemode)
    2346           6 :                 LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    2347             : 
    2348      241160 :             ExecStoreBufferHeapTuple(tuple, slot, hscan->rs_cbuf);
    2349             : 
    2350             :             /* Count successfully-fetched tuples as heap fetches */
    2351      241160 :             pgstat_count_heap_getnext(scan->rs_rd);
    2352             : 
    2353      241160 :             return true;
    2354             :         }
    2355             :         else
    2356             :         {
    2357             :             /*
    2358             :              * If we get here, it means we've exhausted the items on this page
    2359             :              * and it's time to move to the next.
    2360             :              */
    2361       12736 :             if (!pagemode)
    2362        4188 :                 LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
    2363             : 
    2364       12736 :             ExecClearTuple(slot);
    2365       12736 :             return false;
    2366             :         }
    2367             :     }
    2368             : 
    2369             :     Assert(0);
    2370             : }
    2371             : 
    2372             : 
    2373             : /* ----------------------------------------------------------------------------
    2374             :  *  Helper functions for the above.
    2375             :  * ----------------------------------------------------------------------------
    2376             :  */
    2377             : 
    2378             : /*
    2379             :  * Reconstruct and rewrite the given tuple
    2380             :  *
    2381             :  * We cannot simply copy the tuple as-is, for several reasons:
    2382             :  *
    2383             :  * 1. We'd like to squeeze out the values of any dropped columns, both
    2384             :  * to save space and to ensure we have no corner-case failures. (It's
    2385             :  * possible for example that the new table hasn't got a TOAST table
    2386             :  * and so is unable to store any large values of dropped cols.)
    2387             :  *
    2388             :  * 2. The tuple might not even be legal for the new table; this is
    2389             :  * currently only known to happen as an after-effect of ALTER TABLE
    2390             :  * SET WITHOUT OIDS.
    2391             :  *
    2392             :  * So, we must reconstruct the tuple from component Datums.
    2393             :  */
    2394             : static void
    2395      728324 : reform_and_rewrite_tuple(HeapTuple tuple,
    2396             :                          Relation OldHeap, Relation NewHeap,
    2397             :                          Datum *values, bool *isnull, RewriteState rwstate)
    2398             : {
    2399      728324 :     TupleDesc   oldTupDesc = RelationGetDescr(OldHeap);
    2400      728324 :     TupleDesc   newTupDesc = RelationGetDescr(NewHeap);
    2401             :     HeapTuple   copiedTuple;
    2402             :     int         i;
    2403             : 
    2404      728324 :     heap_deform_tuple(tuple, oldTupDesc, values, isnull);
    2405             : 
    2406             :     /* Be sure to null out any dropped columns */
    2407     6372306 :     for (i = 0; i < newTupDesc->natts; i++)
    2408             :     {
    2409     5643982 :         if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
    2410           0 :             isnull[i] = true;
    2411             :     }
    2412             : 
    2413      728324 :     copiedTuple = heap_form_tuple(newTupDesc, values, isnull);
    2414             : 
    2415             :     /* The heap rewrite module does the rest */
    2416      728324 :     rewrite_heap_tuple(rwstate, tuple, copiedTuple);
    2417             : 
    2418      728324 :     heap_freetuple(copiedTuple);
    2419      728324 : }
    2420             : 
    2421             : /*
    2422             :  * Check visibility of the tuple.
    2423             :  */
    2424             : static bool
    2425         812 : SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
    2426             :                        HeapTuple tuple,
    2427             :                        OffsetNumber tupoffset)
    2428             : {
    2429         812 :     HeapScanDesc hscan = (HeapScanDesc) scan;
    2430             : 
    2431         812 :     if (scan->rs_flags & SO_ALLOW_PAGEMODE)
    2432             :     {
    2433         806 :         uint32      start = 0,
    2434         806 :                     end = hscan->rs_ntuples;
    2435             : 
    2436             :         /*
    2437             :          * In pageatatime mode, heap_prepare_pagescan() already did visibility
    2438             :          * checks, so just look at the info it left in rs_vistuples[].
    2439             :          *
    2440             :          * We use a binary search over the known-sorted array.  Note: we could
    2441             :          * save some effort if we insisted that NextSampleTuple select tuples
    2442             :          * in increasing order, but it's not clear that there would be enough
    2443             :          * gain to justify the restriction.
    2444             :          */
    2445        1556 :         while (start < end)
    2446             :         {
    2447        1556 :             uint32      mid = start + (end - start) / 2;
    2448        1556 :             OffsetNumber curoffset = hscan->rs_vistuples[mid];
    2449             : 
    2450        1556 :             if (tupoffset == curoffset)
    2451         806 :                 return true;
    2452         750 :             else if (tupoffset < curoffset)
    2453         442 :                 end = mid;
    2454             :             else
    2455         308 :                 start = mid + 1;
    2456             :         }
    2457             : 
    2458           0 :         return false;
    2459             :     }
    2460             :     else
    2461             :     {
    2462             :         /* Otherwise, we have to check the tuple individually. */
    2463           6 :         return HeapTupleSatisfiesVisibility(tuple, scan->rs_snapshot,
    2464             :                                             buffer);
    2465             :     }
    2466             : }
    2467             : 
    2468             : /*
    2469             :  * Helper function get the next block of a bitmap heap scan. Returns true when
    2470             :  * it got the next block and saved it in the scan descriptor and false when
    2471             :  * the bitmap and or relation are exhausted.
    2472             :  */
    2473             : static bool
    2474      432110 : BitmapHeapScanNextBlock(TableScanDesc scan,
    2475             :                         bool *recheck,
    2476             :                         uint64 *lossy_pages, uint64 *exact_pages)
    2477             : {
    2478      432110 :     BitmapHeapScanDesc bscan = (BitmapHeapScanDesc) scan;
    2479      432110 :     HeapScanDesc hscan = (HeapScanDesc) bscan;
    2480             :     BlockNumber block;
    2481             :     void       *per_buffer_data;
    2482             :     Buffer      buffer;
    2483             :     Snapshot    snapshot;
    2484             :     int         ntup;
    2485             :     TBMIterateResult *tbmres;
    2486             :     OffsetNumber offsets[TBM_MAX_TUPLES_PER_PAGE];
    2487      432110 :     int         noffsets = -1;
    2488             : 
    2489             :     Assert(scan->rs_flags & SO_TYPE_BITMAPSCAN);
    2490             :     Assert(hscan->rs_read_stream);
    2491             : 
    2492      432110 :     hscan->rs_cindex = 0;
    2493      432110 :     hscan->rs_ntuples = 0;
    2494             : 
    2495             :     /* Release buffer containing previous block. */
    2496      432110 :     if (BufferIsValid(hscan->rs_cbuf))
    2497             :     {
    2498      405780 :         ReleaseBuffer(hscan->rs_cbuf);
    2499      405780 :         hscan->rs_cbuf = InvalidBuffer;
    2500             :     }
    2501             : 
    2502      432110 :     hscan->rs_cbuf = read_stream_next_buffer(hscan->rs_read_stream,
    2503             :                                              &per_buffer_data);
    2504             : 
    2505      432110 :     if (BufferIsInvalid(hscan->rs_cbuf))
    2506             :     {
    2507             :         /* the bitmap is exhausted */
    2508       25938 :         return false;
    2509             :     }
    2510             : 
    2511             :     Assert(per_buffer_data);
    2512             : 
    2513      406172 :     tbmres = per_buffer_data;
    2514             : 
    2515             :     Assert(BlockNumberIsValid(tbmres->blockno));
    2516             :     Assert(BufferGetBlockNumber(hscan->rs_cbuf) == tbmres->blockno);
    2517             : 
    2518             :     /* Exact pages need their tuple offsets extracted. */
    2519      406172 :     if (!tbmres->lossy)
    2520      245782 :         noffsets = tbm_extract_page_tuple(tbmres, offsets,
    2521             :                                           TBM_MAX_TUPLES_PER_PAGE);
    2522             : 
    2523      406172 :     *recheck = tbmres->recheck;
    2524             : 
    2525      406172 :     block = hscan->rs_cblock = tbmres->blockno;
    2526      406172 :     buffer = hscan->rs_cbuf;
    2527      406172 :     snapshot = scan->rs_snapshot;
    2528             : 
    2529      406172 :     ntup = 0;
    2530             : 
    2531             :     /*
    2532             :      * Prune and repair fragmentation for the whole page, if possible.
    2533             :      */
    2534      406172 :     heap_page_prune_opt(scan->rs_rd, buffer);
    2535             : 
    2536             :     /*
    2537             :      * We must hold share lock on the buffer content while examining tuple
    2538             :      * visibility.  Afterwards, however, the tuples we have found to be
    2539             :      * visible are guaranteed good as long as we hold the buffer pin.
    2540             :      */
    2541      406172 :     LockBuffer(buffer, BUFFER_LOCK_SHARE);
    2542             : 
    2543             :     /*
    2544             :      * We need two separate strategies for lossy and non-lossy cases.
    2545             :      */
    2546      406172 :     if (!tbmres->lossy)
    2547             :     {
    2548             :         /*
    2549             :          * Bitmap is non-lossy, so we just look through the offsets listed in
    2550             :          * tbmres; but we have to follow any HOT chain starting at each such
    2551             :          * offset.
    2552             :          */
    2553             :         int         curslot;
    2554             : 
    2555             :         /* We must have extracted the tuple offsets by now */
    2556             :         Assert(noffsets > -1);
    2557             : 
    2558     6066124 :         for (curslot = 0; curslot < noffsets; curslot++)
    2559             :         {
    2560     5820348 :             OffsetNumber offnum = offsets[curslot];
    2561             :             ItemPointerData tid;
    2562             :             HeapTupleData heapTuple;
    2563             : 
    2564     5820348 :             ItemPointerSet(&tid, block, offnum);
    2565     5820348 :             if (heap_hot_search_buffer(&tid, scan->rs_rd, buffer, snapshot,
    2566             :                                        &heapTuple, NULL, true))
    2567     5588006 :                 hscan->rs_vistuples[ntup++] = ItemPointerGetOffsetNumber(&tid);
    2568             :         }
    2569             :     }
    2570             :     else
    2571             :     {
    2572             :         /*
    2573             :          * Bitmap is lossy, so we must examine each line pointer on the page.
    2574             :          * But we can ignore HOT chains, since we'll check each tuple anyway.
    2575             :          */
    2576      160390 :         Page        page = BufferGetPage(buffer);
    2577      160390 :         OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
    2578             :         OffsetNumber offnum;
    2579             : 
    2580     1384660 :         for (offnum = FirstOffsetNumber; offnum <= maxoff; offnum = OffsetNumberNext(offnum))
    2581             :         {
    2582             :             ItemId      lp;
    2583             :             HeapTupleData loctup;
    2584             :             bool        valid;
    2585             : 
    2586     1224270 :             lp = PageGetItemId(page, offnum);
    2587     1224270 :             if (!ItemIdIsNormal(lp))
    2588           0 :                 continue;
    2589     1224270 :             loctup.t_data = (HeapTupleHeader) PageGetItem(page, lp);
    2590     1224270 :             loctup.t_len = ItemIdGetLength(lp);
    2591     1224270 :             loctup.t_tableOid = scan->rs_rd->rd_id;
    2592     1224270 :             ItemPointerSet(&loctup.t_self, block, offnum);
    2593     1224270 :             valid = HeapTupleSatisfiesVisibility(&loctup, snapshot, buffer);
    2594     1224270 :             if (valid)
    2595             :             {
    2596     1224144 :                 hscan->rs_vistuples[ntup++] = offnum;
    2597     1224144 :                 PredicateLockTID(scan->rs_rd, &loctup.t_self, snapshot,
    2598     1224144 :                                  HeapTupleHeaderGetXmin(loctup.t_data));
    2599             :             }
    2600     1224270 :             HeapCheckForSerializableConflictOut(valid, scan->rs_rd, &loctup,
    2601             :                                                 buffer, snapshot);
    2602             :         }
    2603             :     }
    2604             : 
    2605      406166 :     LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
    2606             : 
    2607             :     Assert(ntup <= MaxHeapTuplesPerPage);
    2608      406166 :     hscan->rs_ntuples = ntup;
    2609             : 
    2610      406166 :     if (tbmres->lossy)
    2611      160390 :         (*lossy_pages)++;
    2612             :     else
    2613      245776 :         (*exact_pages)++;
    2614             : 
    2615             :     /*
    2616             :      * Return true to indicate that a valid block was found and the bitmap is
    2617             :      * not exhausted. If there are no visible tuples on this page,
    2618             :      * hscan->rs_ntuples will be 0 and heapam_scan_bitmap_next_tuple() will
    2619             :      * return false returning control to this function to advance to the next
    2620             :      * block in the bitmap.
    2621             :      */
    2622      406166 :     return true;
    2623             : }
    2624             : 
    2625             : /* ------------------------------------------------------------------------
    2626             :  * Definition of the heap table access method.
    2627             :  * ------------------------------------------------------------------------
    2628             :  */
    2629             : 
    2630             : static const TableAmRoutine heapam_methods = {
    2631             :     .type = T_TableAmRoutine,
    2632             : 
    2633             :     .slot_callbacks = heapam_slot_callbacks,
    2634             : 
    2635             :     .scan_begin = heap_beginscan,
    2636             :     .scan_end = heap_endscan,
    2637             :     .scan_rescan = heap_rescan,
    2638             :     .scan_getnextslot = heap_getnextslot,
    2639             : 
    2640             :     .scan_set_tidrange = heap_set_tidrange,
    2641             :     .scan_getnextslot_tidrange = heap_getnextslot_tidrange,
    2642             : 
    2643             :     .parallelscan_estimate = table_block_parallelscan_estimate,
    2644             :     .parallelscan_initialize = table_block_parallelscan_initialize,
    2645             :     .parallelscan_reinitialize = table_block_parallelscan_reinitialize,
    2646             : 
    2647             :     .index_fetch_begin = heapam_index_fetch_begin,
    2648             :     .index_fetch_reset = heapam_index_fetch_reset,
    2649             :     .index_fetch_end = heapam_index_fetch_end,
    2650             :     .index_fetch_tuple = heapam_index_fetch_tuple,
    2651             : 
    2652             :     .tuple_insert = heapam_tuple_insert,
    2653             :     .tuple_insert_speculative = heapam_tuple_insert_speculative,
    2654             :     .tuple_complete_speculative = heapam_tuple_complete_speculative,
    2655             :     .multi_insert = heap_multi_insert,
    2656             :     .tuple_delete = heapam_tuple_delete,
    2657             :     .tuple_update = heapam_tuple_update,
    2658             :     .tuple_lock = heapam_tuple_lock,
    2659             : 
    2660             :     .tuple_fetch_row_version = heapam_fetch_row_version,
    2661             :     .tuple_get_latest_tid = heap_get_latest_tid,
    2662             :     .tuple_tid_valid = heapam_tuple_tid_valid,
    2663             :     .tuple_satisfies_snapshot = heapam_tuple_satisfies_snapshot,
    2664             :     .index_delete_tuples = heap_index_delete_tuples,
    2665             : 
    2666             :     .relation_set_new_filelocator = heapam_relation_set_new_filelocator,
    2667             :     .relation_nontransactional_truncate = heapam_relation_nontransactional_truncate,
    2668             :     .relation_copy_data = heapam_relation_copy_data,
    2669             :     .relation_copy_for_cluster = heapam_relation_copy_for_cluster,
    2670             :     .relation_vacuum = heap_vacuum_rel,
    2671             :     .scan_analyze_next_block = heapam_scan_analyze_next_block,
    2672             :     .scan_analyze_next_tuple = heapam_scan_analyze_next_tuple,
    2673             :     .index_build_range_scan = heapam_index_build_range_scan,
    2674             :     .index_validate_scan = heapam_index_validate_scan,
    2675             : 
    2676             :     .relation_size = table_block_relation_size,
    2677             :     .relation_needs_toast_table = heapam_relation_needs_toast_table,
    2678             :     .relation_toast_am = heapam_relation_toast_am,
    2679             :     .relation_fetch_toast_slice = heap_fetch_toast_slice,
    2680             : 
    2681             :     .relation_estimate_size = heapam_estimate_rel_size,
    2682             : 
    2683             :     .scan_bitmap_next_tuple = heapam_scan_bitmap_next_tuple,
    2684             :     .scan_sample_next_block = heapam_scan_sample_next_block,
    2685             :     .scan_sample_next_tuple = heapam_scan_sample_next_tuple
    2686             : };
    2687             : 
    2688             : 
    2689             : const TableAmRoutine *
    2690    19908246 : GetHeapamTableAmRoutine(void)
    2691             : {
    2692    19908246 :     return &heapam_methods;
    2693             : }
    2694             : 
    2695             : Datum
    2696     2509822 : heap_tableam_handler(PG_FUNCTION_ARGS)
    2697             : {
    2698     2509822 :     PG_RETURN_POINTER(&heapam_methods);
    2699             : }

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