Re: Postgresql equal join on function with columns not use index

"James Pang (chaolpan)" <chaolpan(at)cisco(dot)com> writes:
> Looks like it's the function "regexp_replace" volatile and restrict=false make the difference, we have our application role with default search_path=oracle,$user,public,pg_catalog.
> =# select oid,proname,pronamespace::regnamespace,prosecdef,proisstrict,provolatile from pg_proc where proname='regexp_replace' order by oid;
> oid | proname | pronamespace | prosecdef | proisstrict | provolatile
> -------+----------------+--------------+-----------+-------------+-------------
> 2284 | regexp_replace | pg_catalog | f | t | i
> 2285 | regexp_replace | pg_catalog | f | t | i
> 17095 | regexp_replace | oracle | f | f | v
> 17096 | regexp_replace | oracle | f | f | v
> 17097 | regexp_replace | oracle | f | f | v
> 17098 | regexp_replace | oracle | f | f | v

Why in the world are the oracle ones marked volatile? That's what's
preventing them from being used in index quals.

regards, tom lane