Louis-David Mitterrand <cunctator@apartia.ch> writes:
> Is there a way to know which columns are being UPDATEd or INSERTEd from
> inside a trigger, either in C or pl/pgsql?
Huh? An INSERT always inserts all columns, by definition. Some of them
might be null and/or equal to their default values, but they're all
there.
For an UPDATE, you could check to see whether old.col = new.col.
This would miss the case where an UPDATE command is explicitly setting
a column to the same value it already had; dunno if you care or not.
regards, tom lane