Re: [GENERAL] Misunderstanding transactions and locks

2010-06-17 Thread Michael P. Soulier
On 16/06/10 Tom Lane did say: row exclusive mode does not block itself. Specifically, see the table in http://www.postgresql.org/docs/8.3/static/explicit-locking.html#LOCKING-TABLES Exclusive lock modes are those that conflict with themselves; to wit, SHARE ROW EXCLUSIVE mode or higher.

[GENERAL] Misunderstanding transactions and locks

2010-06-16 Thread Michael P. Soulier
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

Re: [GENERAL] Misunderstanding transactions and locks

2010-06-16 Thread Scott Marlowe
On Wed, Jun 16, 2010 at 10:21 AM, Michael P. Soulier michael_soul...@mitel.com wrote: 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

Re: [GENERAL] Misunderstanding transactions and locks

2010-06-16 Thread Alvaro Herrera
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

Re: [GENERAL] Misunderstanding transactions and locks

2010-06-16 Thread Tom Lane
Alvaro Herrera alvhe...@commandprompt.com writes: Excerpts from Michael P. Soulier's message of mié jun 16 12:21:16 -0400 2010: 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