From: Jesper Krogh <jesper@krogh.cc>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Neil Whelchel <neil.whelchel@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Slow count(*) again...
Date: Wed, 13 Oct 2010 19:59:48 +0200
Message-ID: <4CB5F394.6090909@krogh.cc> (raw)
In-Reply-To: <AANLkTi=Cn1N8keywMbePZPiezg9cn_EXQZiLzF7cym+q@mail.gmail.com>
References: <201010091626.18636.neil.whelchel@gmail.com>
<201010130138.39893.neil.whelchel@gmail.com>
<4CB572CF.4080709@catalyst.net.nz>
<201010130316.12922.neil.whelchel@gmail.com>
<AANLkTi=Cn1N8keywMbePZPiezg9cn_EXQZiLzF7cym+q@mail.gmail.com>
On 2010-10-13 15:28, Robert Haas wrote:
> On Wed, Oct 13, 2010 at 6:16 AM, Neil Whelchel<neil.whelchel@gmail.com> wrote:
>
>> I might go as far as to rattle the cage of the developers to see if it makes
>> any sense to add some column oriented storage capability to Postgres. That
>> would be the hot ticket to be able to specify an attribute on a column so that
>> the back end could shadow or store a column in a column oriented table so
>> aggregate functions could work on them with good efficiency, or is that an
>> INDEX?
>>
> I'd love to work on that, but without funding it's tough to find the
> time. It's a big project.
>
Is it hugely different from just getting the visibillity map suitable
for doing index-only scans and extracting values from the index
directly as Heikki has explained?
That would essentially do a column oriented table (the index itself)
of a specific columns (or column set).
... still a huge task though.
--
Jesper
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: jesper@krogh.cc, robertmhaas@gmail.com, neil.whelchel@gmail.com
Subject: Re: Slow count(*) again...
In-Reply-To: <4CB5F394.6090909@krogh.cc>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox