Re: TODO: trigger features

Tom Lane wrote:

>Andreas Pflug <pgadmin@pse-consulting.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?
>
No, this is not the case.

UPDATE foo SET x=x, y=y
is different from
UPDATE foo SET y=y
if triggers maintaining x are involved. I had this case, and had to do 
quite weird stuff to implement this.

Regards,
Andreas