Re: index scan and functions

On Mon, Jul 19, 2010 at 05:55:48PM +0200, arno wrote:
> But when using a custom function to compute my where parameter

> inet_to_bigint is a function that transform an inet address its integer representation.

> Is there a way, either to put function return value in a variable, or to tell
> postgres to still use a sequential scan ?

I'd guess your function is labeled as "VOLATILE".  This is saying that
the function has "side effects", but from the function's name I'd guess
that it doesn't and the only purpose of calling the function is to get
its return value.  I'd expect that labeling it as STABLE would cause PG
to do what you're expecting.  More details here:

  http://www.postgresql.org/docs/current/static/xfunc-volatility.html

--
  Sam  http://samason.me.uk/