Re: function executes sql 100 times longer it should

once again - thank you Vyacheslav for your quick answer.

I have to ask you one more question - is it possible to make a planer
act according to passed parameters, or is the plan predefined on
creating the function?


Vyacheslav Kalinin rašė:
> Apparently your problem starts here:
>
> > ->  Function Scan on filter_b_preke_matoma  (cost=0.00..267.50
> rows=5 width=126) (actual time=6.580..11.766 rows=2820 loops=1)
> >                                                  Filter:
> (((prek_pavadinimas)::text ~~* (('%'::text || ($3)::text) ||
> '%'::text)) OR ($3 IS NULL))
>
> Planner expects to see only somewhat 5 rows after function scan with
> the filter but get ~3000, which is not a surprise if one looks at your
> plain SQL query, corresponding WHERE part:
>
>  AND ((prek_pavadinimas ILIKE ('%'||null||'%')) OR null is NULL)
>
> As I mentioned conditions like this get wrapped (to TRUE in your
> case), so with plain SQL planner does not even try to estimate ILIKE
> filter effect.
>
>


--
Julius Tuskenis
Programavimo skyriaus vadovas
UAB nSoft
mob. +37068233050