I have a situation that I'd like some help resolving.
Using PostgreSQL 8.4.<reasonably recent> on Linux, I have three things
coming together that cause me pain. I have a VIEW used by a bunch of
queries. Usually, these queries are fairly short (subsecond) but
sometimes they can be very long (days). I also update this view with
CREATE OR REPLACE VIEW every 15-30 minutes. What I observe, sometimes,
is this:
1. query A comes in. It's a big one.
2. another process comes along, needs to update the view definition.
It issues create or replace view. It blocks on [1].
3. queries B through N come in, are blocked by [2], which is blocked by [1].
4. pandemonium!
I can reduce (some) but not eliminate the need to update the view
multiple times a day. What might be some good ways to prevent queries
B through N blocking?
Addendum: I can work around the issue by timing out and failing the
CREATE OR REPLACE VIEW (by canceling the query) after a short
duration, but is there a better way?
--
Jon