Re: Empty Updates, ON UPDATE triggers and Rules - Mailing list pgsql-general

On Thu, 2009-08-06 at 13:15 -0400, Merlin Moncure wrote:
> in 8.4 you can (and should) do:
> WHERE old = new

I couldn't get that to work in a rule.

>   IF NEW != OLD THEN  -- 8.4 syntax

Does this work correctly in the case of NULLs? It looks like it does,
but that seems strange, because ROW(1, NULL) = ROW(1, NULL) evaluates to
NULL. Where is this documented?

Regards,
    Jeff Davis