Re: Out of Memory errors are frustrating as heck!
Alvaro Herrera <[email protected]>
| Newsgroups | gmane.comp.db.postgresql.performance |
|---|---|
| Message-ID | <[email protected]> |
On 2019-Apr-15, Gunther wrote: > #0 AllocSetAlloc (context=0x1168230, size=385) at aset.c:715 > #1 0x000000000084e6cd in palloc (size=385) at mcxt.c:938 > #2 0x000000000061019c in ExecHashJoinGetSavedTuple (file=file@entry=0x8bbc528, hashvalue=hashvalue@entry=0x7fff2e4ca76c, > tupleSlot=0x10856b8, hjstate=0x11688e0) at nodeHashjoin.c:1277 > #3 0x0000000000610c83 in ExecHashJoinNewBatch (hjstate=0x11688e0) at nodeHashjoin.c:1042 Seems that ExecHashJoinGetSavedTuple stores a minimalTuple and sets the shouldFree flag to "true", and then in ExecHashJoinNewBatch, callee ExecFetchSlotMinimalTuple sets shouldFree to false inconditionally when the slot uses minimal tuple ops. Maybe that's correct, but it does sound like a memory leak is not entirely impossible. I wonder if this fixes it, without causing crashes elsewhere. -- Ãlvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
mintup-free.patch
(text/x-diff, 460 B)
diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c
index 546db02cad0..d47a1b48eec 100644
--- a/src/backend/executor/execTuples.c
+++ b/src/backend/executor/execTuples.c
@@ -1648,7 +1648,7 @@ ExecFetchSlotMinimalTuple(TupleTableSlot *slot,
if (slot->tts_ops->get_minimal_tuple)
{
if (shouldFree)
- *shouldFree = false;
+ *shouldFree = TTS_SHOULDFREE(slot);
return slot->tts_ops->get_minimal_tuple(slot);
}
else