On Fri, Nov 20, 2009 at 3:38 PM, Tom Lane <t...@postgresql.org> wrote: > Log Message: > ----------- > Add a WHEN clause to CREATE TRIGGER, allowing a boolean expression to be > checked to determine whether the trigger should be fired. > > For BEFORE triggers this is mostly a matter of spec compliance; but for AFTER > triggers it can provide a noticeable performance improvement, since queuing of > a deferred trigger event and re-fetching of the row(s) at end of statement can > be short-circuited if the trigger does not need to be fired. > > Takahiro Itagaki, reviewed by KaiGai Kohei.
Random thought: would it be possible to use something like this to optimize foreign key constraints, by not firing them if none of the relevant columns have been updated? ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
