From: David Leangen <postgres@leangen.net>
To: pgsql-performance@postgresql.org
Subject: Re: Delete operation VERY slow...
Date: Fri, 16 Jun 2006 17:12:22 +0900
Message-ID: <1150445542.4812.34.camel@sonoda.bioscene.co.jp> (raw)
In-Reply-To: <674d1f8a0606160022p1b042676gba28553bac5ab5ea@mail.gmail.com>
References: <1150441126.4812.23.camel@sonoda.bioscene.co.jp>
<674d1f8a0606160022p1b042676gba28553bac5ab5ea@mail.gmail.com>
Wow! That was almost instantaneous. I can't believe the difference.
The only inconvenience is that I need to remove all the foreign key
constraints before truncating, then put them back after. But I suppose
it is a small price to pay for this incredible optimization.
Thank you!
On Fri, 2006-06-16 at 12:52 +0530, Gourish Singbal wrote:
>
> David,
>
> Truncate table would be a good idea if u want to delete all the data
> in the table.
> You need not perform vacuum in this case since there are no dead rows
> created.
>
> ~gourish
>
>
> On 6/16/06, David Leangen <postgres@leangen.net> wrote:
>
> Hello!
>
> I am trying to delete an entire table. There are about 41,000
> rows in
> the table (based on count(*)).
>
> I am using the SQL comment: delete from table;
>
> The operation seems to take in the order of hours, rather than
> seconds
> or minutes.
>
> "Explain delete from table" gives me:
>
> QUERY PLAN
> ----------------------------------------------------------------
> Seq Scan on table (cost=0.00..3967.74 rows=115374 width=6)
> (1 row)
>
>
> I am using an Intel Pentium D 2.8GHz CPU. My system has about
> 1.2GB of
> RAM. This should be ok... my database isn't that big, I think.
>
>
> Any ideas why this takes so long and how I could speed this
> up?
>
> Or alternatively, is there a better way to delete all the
> contents from
> a table?
>
>
> Thank you!
>
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings
>
>
>
> --
> Best,
> Gourish Singbal
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: postgres@leangen.net
Subject: Re: Delete operation VERY slow...
In-Reply-To: <1150445542.4812.34.camel@sonoda.bioscene.co.jp>
* 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