Re: Why won't it index scan?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>
Cc: "Ed L(dot)" <pgsql(at)bluepolka(dot)net>, pgsql-general(at)postgresql(dot)org
Subject: Re: Why won't it index scan?
Date: 2006-05-22 22:43:22
Message-ID: 15660.1148337802@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

"Jim C. Nasby" <jnasby(at)pervasive(dot)com> writes:
> On Wed, May 17, 2006 at 10:29:14PM -0400, Tom Lane wrote:
>> The reason the default is currently 10 is just conservatism: it was
>> already an order of magnitude better than what it replaced (a *single*
>> representative value) and I didn't feel I had the evidence to justify
>> higher values. It's become clear that the default ought to be higher,
>> but I've still got no good fix on a more reasonable default. 100 might
>> be too much, or then again maybe not.

> Is the only downside to a large value planning speed? It seems it would
> be hard to bloat that too much, except in cases where people are
> striving for millisecond response times, and those folks had better know
> enough about tuning to be able to adjust the stats target...

It would be nice to have some *evidence*, not unsupported handwaving.

regards, tom lane

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Shelby Cain 2006-05-22 22:49:01 Re: allow LIMIT in UPDATE and DELETE
Previous Message Jim C. Nasby 2006-05-22 22:14:55 Re: Let's make CPgAN!