Re: Query much slower when run from postgres function

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> Mario Splivalo <mario(dot)splivalo(at)megafon(dot)hr> writes:
>> Now I'm confused, why is 'sql' function much slower than 'direct' SELECT?
>
> Usually the reason for this is that the planner chooses a different plan
> when it has knowledge of the particular value you are searching for than
> when it does not. I suppose 'service_id' has a very skewed distribution
> and you are looking for an uncommon value?

For a prepared statement, could the planner produce *several* plans,
if it guesses great sensitivity to the parameter values? Then it
could choose amongst them at run time.

- FChE