Re: Triggers on columns

Itagaki Takahiro <itagaki.takahiro@oss.ntt.co.jp> writes:
> Sure, and I found there might be difference between "UPDATE" and
> "UPDATE OF {all-columns}" triggers. UPDATE trigger is always fired
> when a row is updated even if none of the columns are actually
> modified, but UPDATE OF {all-columns} trigger is fired only when
> at least one of the columns is modified.

I'm betraying the fact that I haven't read the patch, but ...
exactly how, and when, are you determining whether a column has
been "modified"?  I can't count the number of times somebody
has proposed simplistic and incorrect solutions to that.
Usually they forget about BEFORE triggers changing the row.
        regards, tom lane