From: Chris Browne <cbbrowne@acm.org>
To: pgsql-performance@postgresql.org
Subject: Re: Update table performance
Date: Tue, 07 Aug 2007 14:03:06 -0400
Message-ID: <60ps1zgr39.fsf@dba2.int.libertyrms.com> (raw)
References: <435532.80672.qm@web32210.mail.mud.yahoo.com>
bedrockconstruction@yahoo.com (Mark Makarowsky) writes:
> I have a table with 4,889,820 records in it. The
> table also has 47 fields. I'm having problems with
> update performance. Just as a test, I issued the
> following update:
>
> update valley set test='this is a test'
>
> This took 905641 ms. Isn't that kind of slow? There
> aren't any indexes, triggers, constraints or anything
> on this table. The version of Postgres is "PostgreSQL
> 8.2.4 on i686-pc-mingw32, compiled by GCC gcc.exe
> (GCC) 3.4.2 (mingw-special)". The operating
> environment is Windows 2003 Standard Edition w/service
> pack 2. It is 2.20 Ghz with 1.0 GB of RAM. Here is
> the results from Explain:
>
> "Seq Scan on valley (cost=0.00..1034083.57
> rows=4897257 width=601)"
>
> Here are the settings in the postgresql.conf. Any
> ideas or is this the expected speed?
Hmm.
- You asked to update 4,889,820 records.
- It's a table consisting of 8.5GB of data (based on the cost info)
For this to take 15 minutes doesn't seem particularly outrageous.
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To: pgsql-performance@postgresql.org
Cc: cbbrowne@acm.org
Subject: Re: Update table performance
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