Andreas Pflug <pgadmin(at)pse-consulting(dot)de> writes:
> - Implement a way to enable triggers to check which columns are affected
> by the triggering statement.
This can already be done by comparing old and new values, no?
I don't have a lot of sympathy for the idea that checking what the
original UPDATE touched is a good shortcut. Rules or previous triggers
might have changed additional columns.
regards, tom lane