Yes. I don't have exact numbers but quite significant. ToddC
-----Original Message----- From: Bill Culp [mailto:[EMAIL PROTECTED] Sent: Thursday, February 19, 2004 8:09 PM To: Jakarta Commons Users List Subject: Re: Prepared Statement pooling Just curious, Have you seen measurable performance improvement caching PreparedStatements? - Bill Todd Carmichael wrote: >I need different behavior from the Prepared Statement pooling that is >implemented in the DriverAdapterCPDS (at least I think I do). >Basically I want the prepared statement pool to limit the number of >items pooled and if I am out of room, remove the least recently used >element to make room for the new one. Perhaps that is not what a >'pool' is but that is our needs. We have issues with our prepared >statements in that many of them pass in constants that really should be >parameters, so our cache grows very large. We know this is a problem in >our code and will hopefully address this issue because it affects our >app server and db server performance. But for now, our project does >not have time for this kind of refactor. The evictor thread does clean >up those unused prepared statement, but I would like to set a hard >limit on the number of statements and if I reached the limit, evict the >oldest statement. On a side note: the evictor thread on the prepared >statement will create a thread per connection which seems like high >overhead. Right now the GenericKeyedObjectPool is used for pooling >prepared statements and the values for the pool are taken directly from >the values of the connection pool. Is there a different pool >implementation or settings I could set to get this LRU type behavior? I may change the code to use the commons collections LRUMap, that seems like it would have less overhead. > >Thoughts? > > >ToddC > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
