Re: questions on toast tables - Mailing list pgsql-admin

From Warren Little
Subject Re: questions on toast tables
Date
Msg-id 1146416158.2425.0.camel@wjlnotebook
Whole thread Raw
In response to Re: questions on toast tables  (Tom Lane <tgl@sss.pgh.pa.us>)
List 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.little@meridiascapital.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

pgsql-admin by date:

Previous
From: Tom Lane
Date:
Subject: Re: WAL recovery question - 0000001.history
Next
From: Koen Martens
Date:
Subject: Re: IO query