At 12:53p -0400 on Wed, 13 Aug 2008, Martijn van Oosterhout wrote: > On Wed, Aug 13, 2008 at 12:41:41PM -0400, Kevin Hunter wrote: >> Roughly, VACUUM simply reclaims/frees disk space, while VACUUM FULL >> additionally reorganizes disk usage. I'm still don't know *why* this >> leads to index bloat, however, just that it does. I must defer that >> explication to a Postgres guru. > > Because VACUUM FULL needs to move stuff around in the table which means it > need to mess around with the indexes (adding new entries). Ordinary > VACUUM only needs to delete stuff so doesn't cause anywhere near as > many problems.
Hmm. I get the reorganization bit, but so what? Since VACUUM FULL already has an exclusive lock, what prevents it from updating the indexes in-place to point to the new physical disk location? Why does it need to create extra bloat? Or, failing that, what's the reason to not issue a REINDEX CONCURRENTLY automatically after a VACUUM FULL (or something to that effect)? Kevin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
