Re: questions on toast tables

From: Warren Little <warren(dot)little(at)meridiascapital(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-admin(at)postgresql(dot)org
Subject: Re: questions on toast tables
Date: 2006-04-30 16:55:58
Message-ID: 1146416158.2425.0.camel@wjlnotebook
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-admin

Tom,
thanks much for your help, the cluster command did the trick.
fyi running 8.1.2

On Sat, 2006-04-29 at 14:48 -0400, Tom Lane wrote:
> Warren Little <warren(dot)little(at)meridiascapital(dot)com> writes:
> > Could this be the reference to the toast table that is preventing the
> > vacuum from deleting the toast data? And what purges "dropped" columns
> > if not a full vacuum.
>
> Actually, the way that toast references work is that they'll go away at
> the next update of the row containing the reference. The reason you've
> still got a pile of unremovable toast data is evidently that a lot of
> the parent table's rows have remained untouched since the wide bytea
> column existed. (We choose not to do this housekeeping immediately
> during DROP COLUMN, but to defer it until the next row update.)
>
> One way to clean up the junk would be to do a trivial full-table update
> ("UPDATE foo SET f1 = f1") and then VACUUM FULL, but there are other
> ways that are more efficient. If you're using a PG version released
> within the last year, CLUSTER will do the job nicely.
>
> regards, tom lane
--
Warren Little
Chief Technology Officer
Meridias Capital Inc
1018 W Atherton Dr
SLC, UT 84123
ph 866.369.7763

In response to

Browse pgsql-admin by date

  From Date Subject
Next Message Koen Martens 2006-05-01 12:50:54 Re: Socket Timeouts and fatal errors (please help)
Previous Message Tom Lane 2006-04-29 19:13:44 Re: WAL recovery question - 0000001.history