On Wed, Aug 3, 2011 at 12:33 PM, Pavan Deolasee <pavan.deola...@gmail.com> wrote: > > > The only problem, other than a surprising behavior that you noted, > that I see with this approach is that we might repeatedly try to > truncate a relation which in fact does not have anything to truncate. > The worst thing is we might unnecessarily take an exclusive lock on > the table. >
So it seems we tried to fix this issue sometime back http://archives.postgresql.org/pgsql-hackers/2008-12/msg01994.php But I don't quite understand how the fix would really work. nonempty_pages would most likely be set at a value lower than relpages if the last page in the relation is all-visible according to the visibility map. Did we mean to test (nonempty_pages > 0) there ? But even that may not work except for the case when there are no dead tuples in the relation. Thanks, Pavan -- Pavan Deolasee EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
