Re: Invocation overhead for procedural languages

On 06/ago/08, at 16:04, Pavel Stehule wrote:

> 2008/8/6 Giorgio Valoti <giorgio_v(at)mac(dot)com>:
>> Hi all, I think I've read somewhere in the documentation that the
>> invocation
>> of functions written in procedural languages (with the exception of
>> plpgsql)
>> incur in performance hit due to the call the language interpreter.
>> Is that
>> correct or am I completely off track?
>
> it's depend. Start of interpret is only one overhead.
> Other is date
> conversions to language compatible types (without C and plpgsql).
> Only plpgsql share expression evaluation with database, so it's
> specific overhead only for plpgsql.

So is plpgsql slower on date conversion than other languages? Just
curious: why does shared evaluation add some overhead?

>
>
> […]
>
> but you can load perl after server start - look on preload_libraries
> section in postgresql.conf

Nice to know.

Thank you Pavel
--
Giorgio Valoti