Re: ALTER TABLE SET STATISTICS requires AccessExclusiveLock

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).

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services