Horton

Re: WIP: cross column correlation ...

Alvaro Herrera <alvherre@commandprompt.com>

View thread
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Rod Taylor <rod.taylor@gmail.com>, Bruce Momjian <bruce@momjian.us>, Josh Berkus <josh@agliodbs.com>, PostgreSQL - Hans-Jürgen Schönig <postgres@cybertec.at>, pgsql-hackers Hackers <pgsql-hackers@postgresql.org>, Boszormenyi Zoltan <zb@cybertec.at>
Date: 2011-02-28T18:44:08Z
Lists: pgsql-hackers 
Excerpts from Robert Haas's message of sáb feb 26 02:24:26 -0300 2011:
> On Fri, Feb 25, 2011 at 2:26 PM, Alvaro Herrera
> <alvherre@commandprompt.com> wrote:
> > Excerpts from Rod Taylor's message of vie feb 25 14:03:58 -0300 2011:
> >
> >> How practical would it be for analyze to keep a record of response times for
> >> given sections of a table as it randomly accesses them and generate some
> >> kind of a map for expected response times for the pieces of data it is
> >> analysing?
> >
> > I think what you want is random_page_cost that can be tailored per
> > tablespace.
> 
> We have that.

Oh, right.

> But it's not the same as tracking *sections of a table*.

I dunno.  I imagine if you have a "section" of a table in different
storage than other sections, you created a tablespace and moved the
partition holding that section there.  Otherwise, how do you prevent the
tuples from moving to other "sections"?  (We don't really have a concept
of "sections" of a table.)

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support