I get the idea but I can't change the structure of the database by adding
anything. I have a database from which I have to retrieve some history data for
recovery purposes.
> Date: Fri, 27 Aug 2010 13:11:47 -0400
> From: webmas...@dhs-club.com
> To: lukasz.brodz...@hotmail.com; pgsql-admin@postgresql.org
> Subject: Re: [ADMIN] Tuple changes from relfilenodes
>
> >> Are you looking for statistics or the actual prior versions of
> >> rows?
> >
> > I'm looking for actual versions of row data. What I want to
> > achieve as a final result is a kind of data change history.
>
> We just use ON DELETE rules on the tables where we want to maintain a
> history. In most cases, we just copy the old record to the archive table
> which has an additional timestamp column with a default of NOW() to indicate
> the date of archival. In one case, where the table schema is large, changes
> are "frequent" and the changes are often minimal, we only archive a small
> subset of data based on what is changing. If the changes affect columns
> outside of the small subset, then we archive the whole record.
>
> Bill MacArthur
>
