Some memory not freed at the exit of RelationBuildPartitionDesc()
| От | amul sul |
|---|---|
| Тема | Some memory not freed at the exit of RelationBuildPartitionDesc() |
| Дата | |
| Msg-id | CAAJ_b952=5fLxfDS3rd01w9D=wM9OTSowrXuOZdG41dYDk56Dw@mail.gmail.com обсуждение исходный текст |
| Ответы |
Re: Some memory not freed at the exit of RelationBuildPartitionDesc()
|
| Список | pgsql-hackers |
Hi,
In RelationBuildPartitionDesc(), a memory space that use to gather partitioning
bound info wasn't free at the end. This might not a problem because this
allocated memory will eventually be recovered when the top-level context is
freed, but the case when a partitioned table having 1000s or more partitions and
this partitioned relation open & close, and its cached entry invalidated in loop
then we'll have too may call to RelationBuildPartitionDesc() which will keep
wasting some space with every loop.
bound info wasn't free at the end. This might not a problem because this
allocated memory will eventually be recovered when the top-level context is
freed, but the case when a partitioned table having 1000s or more partitions and
this partitioned relation open & close, and its cached entry invalidated in loop
then we'll have too may call to RelationBuildPartitionDesc() which will keep
wasting some space with every loop.
For a demonstration purpose, I did the following changes to
heap_drop_with_catalog() and tried to drop a partitioned table having 5000
partitions(attached create script) which hit OOM on a machine in no time:
heap_drop_with_catalog() and tried to drop a partitioned table having 5000
partitions(attached create script) which hit OOM on a machine in no time:
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index b7bcdd9d0f..6b7bc0d7ae 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1842,6 +1842,8 @@ heap_drop_with_catalog(Oid relid)
parentOid = get_partition_parent(relid);
LockRelationOid(parentOid, AccessExclusiveLock);
+ rel = relation_open(parentOid, NoLock);
+ relation_close(rel, NoLock);
/*
* If this is not the default partition, dropping it will change the
* default partition's partition constraint, so we must lock it.
index b7bcdd9d0f..6b7bc0d7ae 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1842,6 +1842,8 @@ heap_drop_with_catalog(Oid relid)
parentOid = get_partition_parent(relid);
LockRelationOid(parentOid, AccessExclusiveLock);
+ rel = relation_open(parentOid, NoLock);
+ relation_close(rel, NoLock);
/*
* If this is not the default partition, dropping it will change the
* default partition's partition constraint, so we must lock it.
calculation in temporary memory context which can be released at the end of
RelationBuildPartitionDesc(), thoughts/Comments?
I did the same in the attached patch and the aforesaid OOM issue is disappeared.
Regards,
Amul
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