Re: Suboptimal query plan when using expensive BCRYPT functions - Mailing list pgsql-performance

On 03/22/2014 02:59 AM, Erik van Zijst wrote:
> Is there any way I can get postgres to perform the hash calculations
> on the *result* of the other parts of the where clause, instead of the
> other way around? Or else rewrite the query?

The planner doesn't know that the crypt function is expensive. That can
be fixed with "ALTER FUNCTION crypt(text, text) COST <high value>". Even
with that, I'm not sure if the planner is smart enough to optimize the
query the way you'd want, but it's worth a try.

- Heikki