diff options
| -rw-r--r-- | src/backend/access/heap/heapam.c | 21 | ||||
| -rw-r--r-- | src/backend/executor/nodeSeqscan.c | 6 | ||||
| -rw-r--r-- | src/include/access/relscan.h | 1 |
3 files changed, 14 insertions, 14 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 85fd749b76a..c9b1d5fd04c 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -479,8 +479,6 @@ heapgettup(HeapScanDesc scan, if (valid) { - if (!scan->rs_relpredicatelocked) - PredicateLockTuple(scan->rs_rd, tuple, snapshot); LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK); return; } @@ -748,16 +746,12 @@ heapgettup_pagemode(HeapScanDesc scan, nkeys, key, valid); if (valid) { - if (!scan->rs_relpredicatelocked) - PredicateLockTuple(scan->rs_rd, tuple, scan->rs_snapshot); scan->rs_cindex = lineindex; return; } } else { - if (!scan->rs_relpredicatelocked) - PredicateLockTuple(scan->rs_rd, tuple, scan->rs_snapshot); scan->rs_cindex = lineindex; return; } @@ -1228,13 +1222,26 @@ heap_beginscan_internal(Relation relation, Snapshot snapshot, scan->rs_strategy = NULL; /* set in initscan */ scan->rs_allow_strat = allow_strat; scan->rs_allow_sync = allow_sync; - scan->rs_relpredicatelocked = false; /* * we can use page-at-a-time mode if it's an MVCC-safe snapshot */ scan->rs_pageatatime = IsMVCCSnapshot(snapshot); + /* + * For a seqscan in a serializable transaction, acquire a predicate lock + * on the entire relation. This is required not only to lock all the + * matching tuples, but also to conflict with new insertions into the + * table. In an indexscan, we take page locks on the index pages covering + * the range specified in the scan qual, but in a heap scan there is + * nothing more fine-grained to lock. A bitmap scan is a different story, + * there we have already scanned the index and locked the index pages + * covering the predicate. But in that case we still have to lock any + * matching heap tuples. + */ + if (!is_bitmapscan) + PredicateLockRelation(relation, snapshot); + /* we only need to set this up once */ scan->rs_ctup.t_tableOid = RelationGetRelid(relation); diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c index f356874b441..0f3438d0639 100644 --- a/src/backend/executor/nodeSeqscan.c +++ b/src/backend/executor/nodeSeqscan.c @@ -28,7 +28,6 @@ #include "access/relscan.h" #include "executor/execdebug.h" #include "executor/nodeSeqscan.h" -#include "storage/predicate.h" static void InitScanRelation(SeqScanState *node, EState *estate); static TupleTableSlot *SeqNext(SeqScanState *node); @@ -106,16 +105,11 @@ SeqRecheck(SeqScanState *node, TupleTableSlot *slot) * tuple. * We call the ExecScan() routine and pass it the appropriate * access method functions. - * For serializable transactions, we first acquire a predicate - * lock on the entire relation. * ---------------------------------------------------------------- */ TupleTableSlot * ExecSeqScan(SeqScanState *node) { - PredicateLockRelation(node->ss_currentRelation, - node->ss_currentScanDesc->rs_snapshot); - node->ss_currentScanDesc->rs_relpredicatelocked = true; return ExecScan((ScanState *) node, (ExecScanAccessMtd) SeqNext, (ExecScanRecheckMtd) SeqRecheck); diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h index db1131e2600..57d08b9656e 100644 --- a/src/include/access/relscan.h +++ b/src/include/access/relscan.h @@ -35,7 +35,6 @@ typedef struct HeapScanDescData BlockNumber rs_startblock; /* block # to start at */ BufferAccessStrategy rs_strategy; /* access strategy for reads */ bool rs_syncscan; /* report location to syncscan logic? */ - bool rs_relpredicatelocked; /* predicate lock on relation exists */ /* scan current state */ bool rs_inited; /* false = scan not init'd yet */ |