Guillaume Lelarge <guilla...@lelarge.info> writes:
> I've tried Justin's patch but it didn't help with my memory allocation
> issue. FWIW, I attach the patch I used in v14.
[ looks closer ... ] Ah, that patch is a bit buggy: it fails to do the
right thing in the cases where the loop does a "continue". The attached
revision seems to behave properly.
I still see a small leakage, which I think is due to accumulation of
pending sinval messages for the catalog updates. I'm curious whether
that's big enough to be a problem for Guillaume's use case. (We've
speculated before about bounding the memory used for pending sinval
in favor of just issuing a cache reset when the list would be too
big. But nobody's done anything about it, suggesting that people
seldom have a problem in practice.)
>> DROP OWNED BY likely has similar issues.
> Didn't try it, but it wouldn't be a surprise.
I tried just changing the REASSIGN to a DROP in Justin's example,
and immediately hit
ERROR: out of shared memory
HINT: You might need to increase max_locks_per_transaction.
thanks to the per-object locks we try to acquire. So I'm not
sure that the DROP case can reach an interesting amount of
local memory leaked before it runs out of lock-table space.
regards, tom lane
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 9ea42f805f..d7f0708396 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -65,6 +65,7 @@
#include "storage/lmgr.h"
#include "utils/acl.h"
#include "utils/fmgroids.h"
+#include "utils/memutils.h"
#include "utils/syscache.h"
typedef enum
@@ -1497,6 +1498,7 @@ shdepReassignOwned(List *roleids, Oid newrole)
while ((tuple = systable_getnext(scan)) != NULL)
{
Form_pg_shdepend sdepForm = (Form_pg_shdepend) GETSTRUCT(tuple);
+ MemoryContext cxt, oldcxt;
/*
* We only operate on shared objects and objects in the current
@@ -1510,6 +1512,11 @@ shdepReassignOwned(List *roleids, Oid newrole)
if (sdepForm->deptype != SHARED_DEPENDENCY_OWNER)
continue;
+ cxt = AllocSetContextCreate(CurrentMemoryContext,
+ "shdepReassignOwned",
+ ALLOCSET_DEFAULT_SIZES);
+ oldcxt = MemoryContextSwitchTo(cxt);
+
/* Issue the appropriate ALTER OWNER call */
switch (sdepForm->classid)
{
@@ -1598,6 +1605,10 @@ shdepReassignOwned(List *roleids, Oid newrole)
elog(ERROR, "unexpected classid %u", sdepForm->classid);
break;
}
+
+ MemoryContextSwitchTo(oldcxt);
+ MemoryContextDelete(cxt);
+
/* Make sure the next iteration will see my changes */
CommandCounterIncrement();
}
