Client side cache for prepared queries

Hi there,

Can't find any documentation about an eventual client side cache for
prepared queries, that should be a performance gain when used with
persistent connections :
 * First page open first connection to DB, prepares a request R1,
cache it locally, executes it.
 * Second page reuse first connection, reuse prepared request, just executes it.

The client side caching of these queries seems simple to implement
with an hashtable of queries (as we have not to replace values I'm not
speaking about a result cache, but a prepared query cache.)

Also I never heard of caching of prepared statement server side, so it
should be a great improvement to cache them client side unless I
missed something ?

-- 
Julien Palard