Re: Why would I want to use connection pooling middleware?

On Jan 15, 2009, at 10:08 AM, Tom Lane wrote:

>  As an example, any system catalog update has to be broadcast to all
> live backends, and they all have to dutifully search their catalog
> caches to flush stale entries.  That costs the same whether the
> backend is being put to use or has been sitting idle for minutes.

I didn't realize that.  I wasn't sure what types of overheads were
involved and didn't think about those sorts of things.

> There's no percentage in trying to pool connections from applications
> that are constantly doing something; but webserver sessions tend to
> have
> lots of user "think time" as well as similar DB environments, so often
> they can be pooled profitably.


That makes sense.  Along those lines, how do you actually enable
connection pooling in pgpool-II?  I've RTFM a few times but it doesn't
seem to have a flag for "enable_pooling".  Is "num_init_children"
effectively the same as a hypothetical "max_children?"  If I set it to
"1" and leave "max_pool" at "4", then clients queue up while one at a
time gets to connect.

Sorry, I know this isn't the pgpool-II mailing list.  :-)
--
Kirk Strauser