Prepared queries

"Cyril VELTER" <cyril.velter@metadys.com> writes:

I'm converting an application to use the V3 protocol features in the 7.4
libpq. As I need to make a design choice regarding the use of prepared
statements, I'm wondering what ressources does a prepared statement use on
the server ? If I need to create several hundred in each backend, is there a
big memory overhead ?

It'd depend on the complexity of the query plans, but I'd think order of a
few KB per query.

What's the time spent by the backend to find one
prepared statement into a list of several hundreds of them ?

The prepared queries are indexed by a hash table, so the lookup time
should be fairly constant independent of their number.

regards, tom lane

Thanks for your answer. Is there any way to know at runtime the space
effectively occupied by all prepared statements in a backend ?

cyril

----- Original Message -----
From: "Tom Lane" <tgl@sss.pgh.pa.us>
To: "Cyril VELTER" <cyril.velter@metadys.com>
Cc: <pgsql-general@postgresql.org>
Sent: Thursday, February 12, 2004 12:12 AM
Subject: Re: [GENERAL] Prepared queries

"Cyril VELTER" <cyril.velter@metadys.com> writes:

I'm converting an application to use the V3 protocol features in the 7.4
libpq. As I need to make a design choice regarding the use of prepared
statements, I'm wondering what ressources does a prepared statement use

on

the server ? If I need to create several hundred in each backend, is

there a