On Sunday 18 July 2010 18:02:26 Simon Riggs wrote: > On Sun, 2010-07-18 at 17:28 +0200, Andres Freund wrote: > > Unfortunately the same issue exists with constraint exclusion - and we > > can hardly disable that for serializable transactions... > > Then I think the fix is to look at the xmin values on all of the tables > used during planning and ensure that we only use constraint-based > optimisations in a serializable transaction when our top xmin is later > than the last DDL change (via its xmin). Why not just use a the normal snapshot at that point? Any older constraints should be just as valid for the tuples visible for the to-be-planned query. I also think that would lay groundwork for reducing lock-levels further in the future.
Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
