Re: UDF in C slow

On 11 May 2012 15:57, Inanc Seylan <inanc(dot)seylan(at)gmail(dot)com> wrote:
> Hi all,
>
> I have implemented a user-defined function in C that returns a boolean value
> after some computation. Now I have a query Q such that when I specify the
> function in the WHERE clause of Q, Q runs in 40 secs and if I don't use the
> function it runs in 4 secs. Then I thought that my implementation of this
> function could be slow; so I decided to write a very simple function that
> just returns true without any computation. To my surprise, it also takes
> around 40 seconds to run Q with the new very simple function. Does anybody
> have a clue about what might be going wrong?

Is that a VOLATILE, STABLE or IMMUTABLE function? What's the output of
EXPLAIN ANALYZE?
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