"Michael P. Soulier" <michael_soulier@mitel.com> writes:
> Does postgres implicitely lock tables? I noticed that I had an alter
> table command but I didn't lock, and yet there was a lock being
> requested on the table by that process...
http://www.postgresql.org/docs/8.3/static/explicit-locking.html#LOCKING-TABLES
regards, tom lane