Re: max_prepared_transactions default ... why 5? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: max_prepared_transactions default ... why 5?
Date
Msg-id 200710180507.l9I573r15045@momjian.us
Whole thread Raw
In response to Re: max_prepared_transactions default ... why 5?  (Josh Berkus <josh@agliodbs.com>)
Responses Re: max_prepared_transactions default ... why 5?
List pgsql-hackers
Josh Berkus wrote:
> On Wednesday 17 October 2007 21:35, Tom Lane wrote:
> > Josh Berkus <josh@agliodbs.com> writes:
> > > I'm writing up the new GUCs, and noticed that max_prepared_transactions
> > > defaults to 5.  This is too many for most applications (which don't use
> > > them at all) and far too few for applications which use them regularly.
> >
> > I think the intention was to have enough so you could test 'em (in
> > particular, run the regression tests) without eating resources for
> > the majority of installations that aren't using them.
> >
> > Certainly an installation that *is* using 'em would want a higher
> > setting.
> 
> Yeah, given the amount of memory per xact, I guess we can't actually set the 
> default higher.  I just hate to see a setting that is liable to bite someone 
> on the tuchas so easily.

They will see the failure at 5 faster and adjust it accordingly.  If it
was higher they might hit the limit only under heavy load and it would
surprise them.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://postgres.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: max_prepared_transactions default ... why 5?
Next
From: "Pavel Stehule"
Date:
Subject: Proposal: generate_iterator functions