From: Ed L. <pgsql@bluepolka.net>
To: pgsql-general@postgresql.org
Cc: Bill Moran <wmoran@collaborativefusion.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@commandprompt.com>
Subject: Re: Index bloat of 4x
Date: Thu, 18 Jan 2007 18:42:00 -0700
Message-ID: <200701181842.00696.pgsql@bluepolka.net> (raw)
In-Reply-To: <20070118080715.479b9315.wmoran@collaborativefusion.com>
References: <20070117093223.bcdb302e.wmoran@collaborativefusion.com>
<19674.1169104105@sss.pgh.pa.us>
<20070118080715.479b9315.wmoran@collaborativefusion.com>
On Thursday January 18 2007 6:07 am, Bill Moran wrote:
> Right. It doesn't _look_ that way from the graph, but that's
> because I only graph total DB size. I expect if I graphed
> data and index size separately, it would be evident.
pg_total_relation_size() might give you what you want there.
> At this point, I'm going to assume that my question of, "Is
> this 4x bloat strange enough to warrant further investigation"
> is "no". It seems like this amount of bloat isn't terribly
> unusual, and that the people working on improving this sort of
> thing already have enough examples of it.
I afraid I don't see how any of the answers I saw discussed fit a
24x7 operation. Reindex, drop index, vacuum full, ... they all
block production queries of one sort or another for significant
periods of time (minutes) on large (multi/tens of GB) tables,
and thus are infeasible for true 24x7 operations. What it seems
we really need is something to remove the bloat without blocking
production DML queries, while under significant query load, with
very large tables. This bloat issue is by far our biggest
headache on the DB side.
Ed
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-general@postgresql.org
Cc: pgsql@bluepolka.net, wmoran@collaborativefusion.com, tgl@sss.pgh.pa.us, alvherre@commandprompt.com
Subject: Re: Index bloat of 4x
In-Reply-To: <200701181842.00696.pgsql@bluepolka.net>
* 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