On Wed, 2010-07-28 at 15:24 +0300, Peter Eisentraut wrote: > On tor, 2010-07-15 at 10:24 +0100, Simon Riggs wrote: > > Patch to reduce lock levels for > > ALTER TABLE > > CREATE TRIGGER > > CREATE RULE > > Tried this out, but $subject is still the case. The problem is that > ATRewriteCatalogs() calls AlterTableCreateToastTable() based on what it > thinks the subcommands are, and AlterTableCreateToastTable() takes an > AccessExclusiveLock. > > This could possibly be addressed by moving AT_SetStatistics to > AT_PASS_MISC in order to avoid the TOAST table call. > > In a related matter, assigning ShareUpdateExclusiveLock to AT_SetStorage > doesn't work either, because the TOAST table call needs to be done in > that case. > > Perhaps this logic needs to be refactored a bit more so that there > aren't any inconsistencies between the lock modes and the "passes", > which could lead to false expectations and deadlocks.
Thanks for your comments. Will reconsider and update. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
