Michael If you issue DDL commands (add constraint, drop constraint etc) against a table, any uncommitted transactions of your session are automatically committed. If the commit fails (due to constraints, or triggers, for example), the DDL fails. If another user has open transactions, your DDL will abort (or wait / hang) Stefan ========================= Stefan P Knecht CEO & Founder s@xxxxxxxx 10046 Consulting GmbH Schwarzackerstrasse 29 CH-8304 Wallisellen Switzerland Phone +41-(0)8400-10046 Cell +41 (0) 79 571 36 27 info@xxxxxxxx http://www.10046.ch ========================= On Wed, Nov 10, 2010 at 6:03 PM, Michael Moore <michaeljmoore@xxxxxxxxx>wrote: > > Do you have any un commited transactions against this table?