Excerpts from Matthew Excell's message of lun jun 07 15:33:27 -0400 2010:
> I'm on PostgreSQL 8.3.11 on Debian. > > I have a small piece of DDL (alter table title drop column is_target) that > hangs "waiting" forever. (I've waited hours - it still shows as waiting in > pg_top.) I have restarted the database - even tried it in single-user mode > - but it still waits. > > When I execute a query to get lock info: > > select > pg_class.relname,pg_locks.locktype,mode,virtualtransaction,database,relation,granted > from pg_class,pg_locks where pg_class.relfilenode=pg_locks.relation; > > (These are all the columns in pg_locks with anything but null in them.) > > relname | locktype | mode | > virtualtransaction | database | relation | granted > --------------------------------------+----------+-----------------+--------------------+----------+----------+--------- > property_key_name_index | relation | AccessShareLock | > -1/22805859 | 64197 | 361377 | t
uh. Check pg_prepared_transactions (or was it pg_prepared_xacts?) and do a ROLLBACK PREPARED (or COMMIT PREPARED) if there's anything that shouldn't be there.
-- Álvaro Herrera <alvherre@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support
