David Fetter <david@fetter.org> writes:
> On Fri, Nov 02, 2007 at 11:49:38AM -0400, Andrew Dunstan wrote:
>> At the moment I have to write things like:
>>
>> update tname set foo = bar ... where foo is null or foo <> bar
> One way I've done this is make RULEs which basically drop non-updating
> "UPDATEs" on the floor.
A BEFORE UPDATE trigger would be better, and probably hardly more
expensive than a wired-in facility (especially if you were willing to
write it in C).
regards, tom lane