Re: please explain vacuum with WAL - Mailing list pgsql-general

From Albe Laurenz
Subject Re: please explain vacuum with WAL
Date
Msg-id D960CB61B694CF459DCFB4B0128514C2024B0A80@exadv11.host.magwien.gv.at
Whole thread Raw
In response to please explain vacuum with WAL  (Dmitry Melekhov <dm@belkam.com>)
List pgsql-general
Dmitry Melekhov wrote:
> I tried to ask this question in novice list.
> Just because there are no replies I try here.
> This is really novice question- I'm oracle dba :-)
> 
> > I just installed 8.3 with WAL enabled.
> > But I can't understand why postgres generated many archive logs during
> > vacuum, if WAL is enabled.
> > Could you explain?

VACUUM changes the database, and these changes go to the transaction log.

If VACUUM changes a lot, you can end up with many archived WAL files.

There's no correspondence in Oracle, but think of it as an
"ALTER TABLE <name> MOVE" except that there is no NOLOGGING clause.

Yours,
Laurenz Albe

pgsql-general by date:

Previous
From: "Dennis Brakhane"
Date:
Subject: Re: Query running slow but was running fine before
Next
From: "Long Cui"
Date:
Subject: select command doesnot work