On Wed, Dec 06, 2006 at 08:26:45AM -0500, Dave Cramer wrote: > Apparently I've completely misunderstood MVCC then.... My > understanding is that unless you do a select ... for update then > update the rows will not be locked . The discussion was about updates, not selects. Selects do not in general lock (except for ... for update, as you say). To (partially) answer the original question: The number of columns updated does not matter for the locking situation. /* Steinar */ -- Homepage: http://www.sesse.net/