From: | David Fetter <david(at)fetter(dot)org> |
---|---|
To: | pgsql-announce(at)postgresql(dot)org |
Subject: | Re: == PostgreSQL Weekly News - February 21 2010 == |
Date: | 2010-02-22 15:40:08 |
Message-ID: | 20100222154007.GK2917@fetter.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-announce |
On Sun, Feb 21, 2010 at 11:55:34PM -0800, David Fetter wrote:
> == PostgreSQL 9.0 Feature of the Week ==
>
> You can now control the behavior of distinct values per column using
> ALTER TABLE...ALTER COLUMN...SET STATISTICS DISTINCT. Positive
> numbers are assumed to be the number of distinct values, 0 tells the
> planner to use the results from ANALYZE, and negative numbers (which
> should be between -1 and 0, cause the planner to estimate the number
> of distinct values as the estimated number of rows multiplied by the
> absolute value of the number.
This has changed since it was originally written. The syntax now is
ALTER TABLE..ALTER COLUMN...SET (attribute=value, ...)
For 9.0, attribute can be n_distinct or n_distinct_inherited, and this
may expand in future major versions.
Thanks to Robert Haas for pointing this out :)
Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
Skype: davidfetter XMPP: david(dot)fetter(at)gmail(dot)com
iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics
Remember to vote!
Consider donating to Postgres: http://www.postgresql.org/about/donate
From | Date | Subject | |
---|---|---|---|
Next Message | Joshua D. Drake | 2010-02-23 18:55:10 | PostgreSQL Conference East Talks Announced! |
Previous Message | Oliver Kohll | 2010-02-22 14:45:23 | RunJasperReports version 1.1 released |