Re: How to analyze function performance - Mailing list pgsql-performance

From Tomas Vondra
Subject Re: How to analyze function performance
Date
Msg-id 44915A9D.6090407@fuzzy.cz
Whole thread Raw
In response to How to analyze function performance  ("Mindaugas" <mind@bi.lt>)
List pgsql-performance
It depends what is the purpose of the function. If it's mainly a
container for a heap of SQL queries along with some simple IF, ELSE
etc. then I use two simple ways to analyze the performance (or lack
of performance):

1) I use a lot of debug messages

2) I print out all SQL and the execute EXPLAIN / EXPLAIN ANALYZE on them

If the function is mainly a computation of something, it's usually nice
to try to use for example C language, as it's much faster than PL/pgSQL
for this type of functions.

But it depends on what you are trying to do in that function ...

Tomas

>   Hello,
>
>   Is it possible to somehow analyze function performance? E.g.
> we are using function cleanup() which takes obviously too much time
> to execute but I have problems trying to figure what is slowing things
> down.
>
>   When I explain analyze function lines step by step it show quite
> acceptable performance.
>
>   PostgreSQL 8.0 is running on two dual core Opterons.
>
>   Thanks,
>
>   Mindaugas

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