Re: Misunderstanding transactions and locks

Excerpts from Michael P. Soulier's message of mié jun 16 12:21:16 -0400 2010:
> Hi,
>
> I'm using Django with Postgres 8.3.9 on CentOS Linux.
>
> I'm trying to figure out why locking isn't working as I'm expecting. I have a
> an operation wrapped in a transaction where I explicitely grab an exclusive
> lock on my table. When another process concurrently runs to do the same, it
> should block on attempting to acquire the exclusive lock, no?

> 2010-06-16 12:14:31.913008500 LOG:  statement: LOCK TABLE instances IN ROW
> EXCLUSIVE MODE

"row exclusive mode" does not block itself.

--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support