On Mon, May 14, 2007 at 05:42:38PM +0400, Dmitry Koterov wrote:
> >
> >> >> So, if anybody reads from sl_log_status, it blocks until anything is
> >> >written
> >> >> to sl_log_status.

> Hmmm... But in postgres read operations never blocks other operations (by
> default) because of versioning. So, while all the replicas are blocked
> waiting for a new event, they are still able to process a lot of read
> queries coming from the site.

I must misunderstand you, then.  What you wrote (above) is that
you're going to block readers until something writes.  That suggests
to me that you're taking some sort of read-blocking lock (you can do
that: LOCK TABLE IN ACCESS EXCLUSIVE MODE will in fact block
everything).

I guess I still don't understand how any of this helps you, though.

A

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Andrew Sullivan  | ajs at crankycanuck.ca
The plural of anecdote is not data.
		--Roger Brinner