> we are facing a few problems with PL/SQL Code..
>
> 1) In Exceptions ORACLE have something called WHEN OTHERS THEN cluase.I
> can't find a replacement for that in
> PostGreSQL.
What does it do?
> 2 Oracle have a function USERENV to get the user session
> information.Is there any replacement available in PostGres. ?
CURRENT_USER (I believe this is per spec)
> 3 Is there any replace available for INSTEAD OF INSERT/DELETE/UPDATE
> for triggers in PostGreSQL.
You might have some luck with Rules (CREATE RULE) if you are writing
data to a different table. Otherwise you're stuck with somewhat more
complicated triggers.