pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed

From: hubert depesz lubaczewski <depesz@depesz.com>
To: AI Rumman <rummandba@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: add column with default value is very slow
Date: Tue, 11 Sep 2012 16:05:54 +0200
Message-ID: <20120911140554.GA8922@depesz.com> (raw)
In-Reply-To: <CAGoODpcDzW6HRDYygi9M5jRcp0X+JQ6CKEiMgCDpGSStUpiDpw@mail.gmail.com>
References: <CAGoODpdBTkhXDuOQDLxuEJYrWfsZZCi_tkjgzDyzPRGDHeQ9ag@mail.gmail.com>
	<20120911134425.GA27828@depesz.com>
	<CAGoODpeorc_7U57NYKsf68Gd3wi9VM+=2kJDZ=89Tk=J=XE=pg@mail.gmail.com>
	<20120911135939.GA1656@depesz.com>
	<CAGoODpcDzW6HRDYygi9M5jRcp0X+JQ6CKEiMgCDpGSStUpiDpw@mail.gmail.com>

On Tue, Sep 11, 2012 at 08:04:06PM +0600, AI Rumman wrote:
> Table size is 1186 MB.

if it takes long, it just means that your IO is slow.

> I split the command in three steps as you said, but the result same during
> the update operation.

three? I was showing four steps, and one of them is usually consisting
hundreds, if not thousands, of queries.

> One more thing, I have just restored the db from dump and analyzed it and
> I am using Postgresql 9.1 with 3 GB Ram with dual core machine.

so it looks like your IO channel is slow.

Best regards,

depesz

-- 
The best thing about modern society is how easy it is to avoid contact with it.
                                                             http://depesz.com/

view thread (8+ messages)  latest in thread

Message-ID: <20120911140554.GA8922@depesz.com>
Permalink:  ../20120911140554.GA8922@depesz.com/
Also on:    postgresql.org/message-id/20120911140554.GA8922@depesz.com

copy link · copy postgr.es

reply

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: depesz@depesz.com, rummandba@gmail.com
  Subject: Re: add column with default value is very slow
  In-Reply-To: <20120911140554.GA8922@depesz.com>

* 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