Pavel Stehule escribió: > Hello > > it is expected behave? > > 1.session > > postgres=# begin; > BEGIN > postgres=# lock oo IN ACCESS EXCLUSIVE MODE; > LOCK TABLE > > 2. session > > postgres=# select * from oo for update nowait; > > hangs forever ....
"select for update nowait" would raise an error if the tuple-level lock is being held by some other process; but what's making it wait here is the table-level lock. Now, is this the right behavior? I'm not sure. But I know for certain that making it behave as you expect is very tricky. The table lock is grabbed during parse analysis; we'd have to postpone grabbing the lock until after we have had the chance to notice that there's a FOR UPDATE clause for the table with a NOWAIT option attached. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
