Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit186655e

Browse files
committed
Adjust nodeBitmapIndexscan.c to not keep the index open across calls,
but just to open and close it during MultiExecBitmapIndexScan. Thisavoids acquiring duplicate resources (eg, multiple locks on the samerelation) in a tree with many bitmap scans. Also, don't bother tolock the parent heap at all here, since we must be underneath aBitmapHeapScan node that will be holding a suitable lock.
1 parent8403741 commit186655e

File tree

2 files changed

+30
-88
lines changed

2 files changed

+30
-88
lines changed

‎src/backend/executor/nodeBitmapIndexscan.c‎

Lines changed: 29 additions & 83 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.5 2005/04/2417:32:46 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.6 2005/04/2418:16:38 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -41,6 +41,8 @@ MultiExecBitmapIndexScan(BitmapIndexScanState *node)
4141
{
4242
#defineMAX_TIDS1024
4343
TIDBitmap*tbm;
44+
Oidindxid;
45+
RelationindexRelation;
4446
IndexScanDescscandesc;
4547
ItemPointerDatatids[MAX_TIDS];
4648
int32ntids;
@@ -58,9 +60,22 @@ MultiExecBitmapIndexScan(BitmapIndexScanState *node)
5860
ExecReScan((PlanState*)node,NULL);
5961

6062
/*
61-
* extract necessary information from index scan node
63+
* We do not open or lock the base relation here. We assume that an
64+
* ancestor BitmapHeapScan node is holding AccessShareLock on the
65+
* heap relation throughout the execution of the plan tree.
6266
*/
63-
scandesc=node->biss_ScanDesc;
67+
68+
/*
69+
* open the index relation and initialize relation and scan
70+
* descriptors. Note we acquire no locks here; the index machinery
71+
* does its own locks and unlocks.
72+
*/
73+
indxid= ((BitmapIndexScan*)node->ss.ps.plan)->indxid;
74+
indexRelation=index_open(indxid);
75+
scandesc=index_beginscan_multi(indexRelation,
76+
node->ss.ps.state->es_snapshot,
77+
node->biss_NumScanKeys,
78+
node->biss_ScanKeys);
6479

6580
/*
6681
* Prepare the result bitmap. Normally we just create a new one to pass
@@ -98,6 +113,12 @@ MultiExecBitmapIndexScan(BitmapIndexScanState *node)
98113
CHECK_FOR_INTERRUPTS();
99114
}
100115

116+
/*
117+
* close the index relation
118+
*/
119+
index_endscan(scandesc);
120+
index_close(indexRelation);
121+
101122
/* must provide our own instrumentation support */
102123
if (node->ss.ps.instrument)
103124
InstrStopNodeMulti(node->ss.ps.instrument,nTuples);
@@ -109,24 +130,18 @@ MultiExecBitmapIndexScan(BitmapIndexScanState *node)
109130
*ExecBitmapIndexReScan(node)
110131
*
111132
*Recalculates the value of the scan keys whose value depends on
112-
*information known at runtime and rescans the indexed relation.
113-
*Updating the scan key was formerly done separately in
114-
*ExecUpdateIndexScanKeys. Integrating it into ReScan makes
115-
*rescans of indices and relations/general streams more uniform.
116-
*
133+
*information known at runtime.
117134
* ----------------------------------------------------------------
118135
*/
119136
void
120137
ExecBitmapIndexReScan(BitmapIndexScanState*node,ExprContext*exprCtxt)
121138
{
122139
ExprContext*econtext;
123140
ExprState**runtimeKeyInfo;
124-
Indexscanrelid;
125141

126142
econtext=node->biss_RuntimeContext;/* context for runtime
127143
* keys */
128144
runtimeKeyInfo=node->biss_RuntimeKeyInfo;
129-
scanrelid= ((BitmapIndexScan*)node->ss.ps.plan)->scan.scanrelid;
130145

131146
if (econtext)
132147
{
@@ -194,8 +209,6 @@ ExecBitmapIndexReScan(BitmapIndexScanState *node, ExprContext *exprCtxt)
194209

195210
node->biss_RuntimeKeysReady= true;
196211
}
197-
198-
index_rescan(node->biss_ScanDesc,node->biss_ScanKeys);
199212
}
200213

201214
/* ----------------------------------------------------------------
@@ -205,58 +218,19 @@ ExecBitmapIndexReScan(BitmapIndexScanState *node, ExprContext *exprCtxt)
205218
void
206219
ExecEndBitmapIndexScan(BitmapIndexScanState*node)
207220
{
208-
Relationrelation;
209-
210-
/*
211-
* extract information from the node
212-
*/
213-
relation=node->ss.ss_currentRelation;
214-
215221
/*
216222
* Free the exprcontext ... now dead code, see ExecFreeExprContext
217223
*/
218224
#ifdefNOT_USED
219225
if (node->biss_RuntimeContext)
220226
FreeExprContext(node->biss_RuntimeContext);
221227
#endif
222-
223-
/*
224-
* close the index relation
225-
*/
226-
if (node->biss_ScanDesc!=NULL)
227-
index_endscan(node->biss_ScanDesc);
228-
229-
if (node->biss_RelationDesc!=NULL)
230-
index_close(node->biss_RelationDesc);
231-
232-
/*
233-
* close the heap relation.
234-
*
235-
* Currently, we do not release the AccessShareLock acquired by
236-
* ExecInitBitmapIndexScan. This lock should be held till end of
237-
* transaction. (There is a faction that considers this too much
238-
* locking, however.)
239-
*/
240-
heap_close(relation,NoLock);
241228
}
242229

243230
/* ----------------------------------------------------------------
244231
*ExecInitBitmapIndexScan
245232
*
246-
*Initializes the index scan's state information, creates
247-
*scan keys, and opens the base and index relations.
248-
*
249-
*Note: index scans have 2 sets of state information because
250-
* we have to keep track of the base relation and the
251-
* index relations.
252-
*
253-
* old comments
254-
*Creates the run-time state information for the node and
255-
*sets the relation id to contain relevant descriptors.
256-
*
257-
*Parameters:
258-
* node: BitmapIndexNode node produced by the planner.
259-
* estate: the execution state initialized in InitPlan.
233+
*Initializes the index scan's state information.
260234
* ----------------------------------------------------------------
261235
*/
262236
BitmapIndexScanState*
@@ -265,10 +239,6 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate)
265239
BitmapIndexScanState*indexstate;
266240
ExprState**runtimeKeyInfo;
267241
boolhave_runtime_keys;
268-
RangeTblEntry*rtentry;
269-
Indexrelid;
270-
Oidreloid;
271-
RelationcurrentRelation;
272242

273243
/*
274244
* create state structure
@@ -306,8 +276,6 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate)
306276
indexstate->biss_RuntimeKeyInfo=NULL;
307277
indexstate->biss_RuntimeContext=NULL;
308278
indexstate->biss_RuntimeKeysReady= false;
309-
indexstate->biss_RelationDesc=NULL;
310-
indexstate->biss_ScanDesc=NULL;
311279

312280
CXT1_printf("ExecInitBitmapIndexScan: context is %d\n",CurrentMemoryContext);
313281

@@ -459,7 +427,6 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate)
459427
runtimeKeyInfo=run_keys;
460428
}
461429

462-
463430
/*
464431
* If all of our keys have the form (var op const), then we have no
465432
* runtime keys so we store NULL in the runtime key info. Otherwise
@@ -489,30 +456,9 @@ ExecInitBitmapIndexScan(BitmapIndexScan *node, EState *estate)
489456
pfree(runtimeKeyInfo);
490457
}
491458

492-
/*
493-
* open the base relation and acquire AccessShareLock on it.
494-
*/
495-
relid=node->scan.scanrelid;
496-
rtentry=rt_fetch(relid,estate->es_range_table);
497-
reloid=rtentry->relid;
498-
499-
currentRelation=heap_open(reloid,AccessShareLock);
500-
501-
indexstate->ss.ss_currentRelation=currentRelation;
502-
indexstate->ss.ss_currentScanDesc=NULL;/* no heap scan here */
503-
504-
/*
505-
* open the index relation and initialize relation and scan
506-
* descriptors. Note we acquire no locks here; the index machinery
507-
* does its own locks and unlocks.(We rely on having AccessShareLock
508-
* on the parent table to ensure the index won't go away!)
509-
*/
510-
indexstate->biss_RelationDesc=index_open(node->indxid);
511-
indexstate->biss_ScanDesc=
512-
index_beginscan_multi(indexstate->biss_RelationDesc,
513-
estate->es_snapshot,
514-
indexstate->biss_NumScanKeys,
515-
indexstate->biss_ScanKeys);
459+
/* We don't keep the table or index open across calls */
460+
indexstate->ss.ss_currentRelation=NULL;
461+
indexstate->ss.ss_currentScanDesc=NULL;
516462

517463
/*
518464
* all done.

‎src/include/nodes/execnodes.h‎

Lines changed: 1 addition & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.127 2005/04/20 15:48:36 tgl Exp $
10+
* $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.128 2005/04/24 18:16:38 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -908,8 +908,6 @@ typedef struct IndexScanState
908908
* that will be evaluated at runtime
909909
*RuntimeContext expr context for evaling runtime Skeys
910910
*RuntimeKeysReady true if runtime Skeys have been computed
911-
*RelationDesc relation descriptor
912-
*ScanDesc scan descriptor
913911
* ----------------
914912
*/
915913
typedefstructBitmapIndexScanState
@@ -921,8 +919,6 @@ typedef struct BitmapIndexScanState
921919
ExprState**biss_RuntimeKeyInfo;
922920
ExprContext*biss_RuntimeContext;
923921
boolbiss_RuntimeKeysReady;
924-
Relationbiss_RelationDesc;
925-
IndexScanDescbiss_ScanDesc;
926922
}BitmapIndexScanState;
927923

928924
/* ----------------

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp