On Sun, 22 Apr 2007, Roland Turner wrote: > I'm working with 7.4, but the 8.2 docs[1] have the same apparent error: > > ROW SHARE > > Conflicts with the EXCLUSIVE and ACCESS EXCLUSIVE lock modes. > > The SELECT FOR UPDATE and SELECT FOR SHARE commands acquire a > lock of this mode on the target table(s) (in addition to ACCESS > SHARE locks on any other tables that are referenced but not > selected FOR UPDATE/FOR SHARE). > > If that conflict list were correct, then ROW SHARE wouldn't conflict > with itself, much less with ROW EXCLUSIVE (required to prevent > INSERT/UPDATE/DELETE); commonsense dictates that it should conflict with > both, and experiment demonstrates that it actually does so. The list in question revolves around table-level locks. Those statements mentioned also take out locks on affected rows. You should be able select for update one row while updating a different row in the same table.
