Skip site navigation (1) Skip section navigation (2)

Peripheral Links

Header And Logo

PostgreSQL
| The world's most advanced open source database.

Site Navigation

Search for
  Advanced Search

Re: index vs. seq scan choice?


  • From: "Joshua D. Drake" <jd(at)commandprompt(dot)com>
  • To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
  • Cc: Alvaro Herrera <alvherre(at)commandprompt(dot)com>, George Pavlov <gpavlov(at)mynewplace(dot)com>, pgsql-general(at)postgresql(dot)org
  • Subject: Re: index vs. seq scan choice?
  • Date: Thu, 24 May 2007 19:57:10 -0700
  • Message-id: <46565086(dot)2040705(at)commandprompt(dot)com>

Tom Lane wrote:
Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
Tom Lane wrote:
(The default statistics target is 10, which is widely considered too
low --- you might find 100 more suitable.)

Does this mean that we should look into raising the default a bit?

Probably ... the question is to what.

The default of 10 was chosen in our usual spirit of conservatism ---
and IIRC it was replacing code that tracked only *one* most common
value, so it was already a factor of 10 better (and more expensive)
than what was there before.  But subsequent history suggests it's
too small.  I'm not sure I want to vote for another 10x increase by
default, though.

Outside of longer analyze times, and slightly more space taken up by the statistics, what is the downside? I mean in reality... what is setting to 100 going to do to effect actual production usage of even a modest machine?

Sincerely,

Joshua D. Drake



			regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
       subscribe-nomail command to majordomo(at)postgresql(dot)org so that your
       message can get through to the mailing list cleanly



--

      === The PostgreSQL Company: Command Prompt, Inc. ===
Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240
Providing the most comprehensive  PostgreSQL solutions since 1997
             http://www.commandprompt.com/

Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate
PostgreSQL Replication: http://www.commandprompt.com/products/




Home | Main Index | Thread Index

Privacy Policy | PostgreSQL Archives hosted by Command Prompt, Inc. | Designed by tinysofa
Copyright © 1996 – 2008 PostgreSQL Global Development Group