Hi Steve:
On Wed, Sep 23, 2015 at 7:25 PM, Steve Pritchard
<steve.pritchard@bto.org> wrote:
> I thought that autovacuum should recover the free space, however I see now
> from the documentation that it doesn't (and that this is deliberate):
....
> I'll do a VACUUM FULL, which I expect to reduce table_len.
Full is for when you've done a drastic reduction on a table. Some
tables oscillate in size, grow and shrink and regrow.., those do not
benefit of vacuum full on the long run, because if you have a table
which oscilates between , let's say, 10G and 20G you need 20G of disk
space, if you shrink and fill the rest with other uses server will
crash on next growth ( some very special cases may be different, but
in general if you have free space is because you create/delete, be it
directly or via MVCC updates, so having it there for next usage is not
so bad ).
Francisco Olarte.
