Re: Hanging VACUUM

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I just noticed that if I do BEGIN;CREATE TABLE..., and then start VACUUM
> of the database in another psql session, the VACUUM hangs until the
> transaction completes.  Is this expected?

Sure.  You have a write lock on pg_class ... not to mention a few other
system tables, but that's the one this trace shows VACUUM is waiting for
exclusive lock on:

> #5  0x811b67a in LockRelation (relation=0x826b01c, lockmode=7) at lmgr.c:141
> #6  0x80735c5 in heap_open (relationId=1259, lockmode=7) at heapam.c:596
        regards, tom lane