Zdenek Kotala <zdenek.kot...@sun.com> writes: > What's about add second bit which mark frozen page (all tuples have freeze > XID)? It should avoid full scan, but extend size of map.
That would only really work if you have a very static table where entire pages get frozen and stay frozen long before the freeze_max_age is reached. Even that wouldn't really work because the partial vacuums would never see those pages. One option is to keep a frozenxid per page which would allow us to visit only pages that need freezing. A more complex scheme would be to have a bit which indicates that all non-frozen xids are > relfrozenxid+100M. When we find all the bits set we can clear them all and bump relfrozenxid by 100M. This would allow regular partial vacuums to gradually move the frozenxid forward. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's 24x7 Postgres support! -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
