> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Aaron Mulder
> Sent: Monday, September 11, 2000 7:33 AM
> To: jBoss Developer
> Subject: [jBoss-Dev] Prepared Statement Caching
>
>
> Remember a while back when we added caching of PreparedStatements
> to the Minerva driver? That is, a pooled connection keeps all the
> PreparedStatements you use open, and reuses them if you try to prepare the
> same statement again.
> It looks like we may run into scaling problems here. I just
> discovered (by accident) that there's a limit in Oracle to the number of
> PreparedStatements you can have open at the same time, and that limit
> appears to be 100 or less, though I don't have a specific number. So if
> you deploy a connection pool in a server with a large number of beans, you
> might imagine that there could easily be 100 separate SQL statements...
> I guess there are probably 2 things we need to do. One is to let
> you disable that caching altogether. And the other is to let you put some
> limit on the number of PreparedStatements it caches. Of course, that's no
> easy task, since now we'd like to implement LRU or something. Sigh.
There is little magic to LRU and I had coded a "generic" LRU in jboss1.0...
(LRU on whatever) all it takes is wrapping the object in something that
keeps track of usage and the pools are built to do just that. No biggy, let
us know when you want to get started on that.
Regardless of the "limit" you mention it will help the scalability, bear in
mind the scalability will be an issue before that limit,
marc
>
> Aaron
>
>
>
