Re: AUTOCOMMIT didn't work...

From: Oliver Elphick <olly(at)lfix(dot)co(dot)uk>
To: Lynn(dot)Tilby(at)asu(dot)edu
Cc: PostgreSQL general list <pgsql-general(at)postgresql(dot)org>, meskes(at)postgresql(dot)org, pgman(at)candle(dot)pha(dot)pa(dot)us, jd(at)commandprompt(dot)com
Subject: Re: AUTOCOMMIT didn't work...
Date: 2003-11-18 22:42:31
Message-ID: 1069195351.16544.1015.camel@linda.lfix.co.uk
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

On Mon, 2003-11-17 at 20:39, Lynn(dot)Tilby(at)asu(dot)edu wrote:
> Hi,
>
> Please see the history below...
>
> Does AUTOCOMMIT as used here functionally replace VACUUM ANALYZE?

No; they are completely separate concepts. Autocommit treats every
statement as a separate transaction; as you have found, this will slow
things down.

VACUUM ANALYZE reads through all rows in a table or all the tables in a
database to set up some statistics to guide the planner. It needs to be
used regularly or the planner will start to produce invalid results and
queries will take a long time. That is not the same reason for taking a
long time as making every statement a separate transaction.

> If I turn on AUTOCOMMIT is every transaction commited as it is
> executed? If this is the case the query will take about twice as
> long... I have actually tested this scenario.
>
> Using AUTOCOMMIT as suggested didn't solve the problem.

I think someone said turn it on when he meant turn it off? It is always
on by default.

To put many statements into one transaction, enclose them all in BEGIN;
and END; They should then run a lot faster.

Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight, UK http://www.lfix.co.uk/oliver
GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839 932A 614D 4C34 3E1D 0C1C
========================================
"A Song for the sabbath day. It is a good thing to
give thanks unto the LORD, and to sing praises unto
thy name, O most High." Psalms 92:1

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Dean Arnold 2003-11-18 23:24:33 Seeking concise PL/pgSQL syntax diagram
Previous Message Johan Fredrik Øhman 2003-11-18 22:37:55 Storing a chain