Re: questions on toast tables

[Warren Little <warren(dot)little(at)meridiascapital(dot)com>]

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