Re: Deadlock in Postgres 8.2

On Sun, 20 Jan 2008, Sebastjan Trepca wrote:

> we are spotting constant deadlocks when altering tables.

See http://www.postgresql.org/docs/8.2/interactive/explicit-locking.html
for information about the ACCESS EXCLUSIVE lock that ALTER TABLE takes.
Anything that is doing that needs to be in as short of a transaction as
possible, and it sounds like you have transactions that are lingering
around for way too long.
http://www.postgresql.org/docs/current/static/tutorial-transactions.html
is an intro to transaction timing.

You can look at who has locks on what using pg_locks, see
http://www.postgresql.org/docs/8.2/static/view-pg-locks.html

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD