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

Commit467963c

Browse files
committed
Prevent query-lifespan memory leakage of SP-GiST traversal values.
The original coding of the SP-GiST scan traversalValue feature (commitccd6eb4) arranged for traversal values to be stored in the query's mainexecutor context. That's fine if there's only one index scan per query,but if there are many, we have a memory leak as successive scans createnew traversal values. Fix it by creating a separate memory context fortraversal values, which we can reset during spgrescan(). Back-patchto 9.6 where this code was introduced.In principle, adding the traversalCxt field to SpGistScanOpaqueDatacreates an ABI break in the back branches. But I (tgl) have littlesympathy for extensions including spgist_private.h, so I'm not veryworried about that. Alternatively we could stick the new field at theend of the struct in back branches, but that has its own downsides.Anton Dignös, reviewed by Alexander KuzmenkovDiscussion:https://postgr.es/m/CALNdv1jb6y2Te-m8xHLxLX12RsBmZJ1f4hESX7J0HjgyOhA9eA@mail.gmail.com
1 parent13c7c65 commit467963c

File tree

2 files changed

+9
-1
lines changed

2 files changed

+9
-1
lines changed

‎src/backend/access/spgist/spgscan.c

Lines changed: 8 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -194,6 +194,9 @@ spgbeginscan(Relation rel, int keysz, int orderbysz)
194194
so->tempCxt=AllocSetContextCreate(CurrentMemoryContext,
195195
"SP-GiST search temporary context",
196196
ALLOCSET_DEFAULT_SIZES);
197+
so->traversalCxt=AllocSetContextCreate(CurrentMemoryContext,
198+
"SP-GiST traversal-value context",
199+
ALLOCSET_DEFAULT_SIZES);
197200

198201
/* Set up indexTupDesc and xs_hitupdesc in case it's an index-only scan */
199202
so->indexTupDesc=scan->xs_hitupdesc=RelationGetDescr(rel);
@@ -209,6 +212,9 @@ spgrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
209212
{
210213
SpGistScanOpaqueso= (SpGistScanOpaque)scan->opaque;
211214

215+
/* clear traversal context before proceeding to the next scan */
216+
MemoryContextReset(so->traversalCxt);
217+
212218
/* copy scankeys into local storage */
213219
if (scankey&&scan->numberOfKeys>0)
214220
{
@@ -229,6 +235,7 @@ spgendscan(IndexScanDesc scan)
229235
SpGistScanOpaqueso= (SpGistScanOpaque)scan->opaque;
230236

231237
MemoryContextDelete(so->tempCxt);
238+
MemoryContextDelete(so->traversalCxt);
232239
}
233240

234241
/*
@@ -463,7 +470,7 @@ spgWalk(Relation index, SpGistScanOpaque so, bool scanWholeIndex,
463470
in.scankeys=so->keyData;
464471
in.nkeys=so->numberOfKeys;
465472
in.reconstructedValue=stackEntry->reconstructedValue;
466-
in.traversalMemoryContext=oldCtx;
473+
in.traversalMemoryContext=so->traversalCxt;
467474
in.traversalValue=stackEntry->traversalValue;
468475
in.level=stackEntry->level;
469476
in.returnData=so->want_itup;

‎src/include/access/spgist_private.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -137,6 +137,7 @@ typedef struct SpGistScanOpaqueData
137137
{
138138
SpGistStatestate;/* see above */
139139
MemoryContexttempCxt;/* short-lived memory context */
140+
MemoryContexttraversalCxt;/* memory context for traversalValues */
140141

141142
/* Control flags showing whether to search nulls and/or non-nulls */
142143
boolsearchNulls;/* scan matches (all) null entries */

0 commit comments

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