Re: how can i view deleted records? - Mailing list pgsql-general

From Martijn van Oosterhout
Subject Re: how can i view deleted records?
Date
Msg-id 20060430103304.GC11912@svana.org
Whole thread Raw
In response to Re: how can i view deleted records?  (Steve Atkins <steve@blighty.com>)
Responses Re: how can i view deleted records?  ("Jim C. Nasby" <jnasby@pervasive.com>)
List pgsql-general
On Sat, Apr 29, 2006 at 07:05:35PM -0700, Steve Atkins wrote:
> >Just kidding... once you delete your records... they are gone.
>
> That's.... not true.
>
> Deleted (or modified) records don't go away until the space
> they use is recycled by the VACUUM command.

Well yes, but with autovacuum you don't know when that might be.

> However, there's no support in postgresql for any sort of
> "time travel", including viewing deleted tuples. The data
> is there on the disk, but there is no clean way to view it
> via the database.

Well, there is a timetravel module which you can enable per table. Just
showing deleted records in general doesn't work well because it
violates all sorts of constraints. If you show deleted records, all of
a sudden your unique indexes arn't unique anymore. Timetravel is
expensive though, which is why it's not by default.

Have a ncie day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.

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