In my application, I have a blocking queue that different processes can add database tasks to. We need this because we need to have the application start up instantly and not wait a few seconds for the DB to initialize.
There is one process that handles all database operations and takes items off the queue and runs them. So this queue could have several items on it. These items at the moment are just the PreparedStatement, with its values set. The issue is that I only have one instance of the PreparedStatement now. So if I reset the parameters on it or do anything like that while one item is in the queue, it would effect both items in the queue. One option that I have would be to queue up the PreparedStatement and the values that should be set. Then when it goes to execute, it sets the parameters and executes the query. What I was wondering was whether I could make a copy of the already prepared statement and just set the values on that copy. Thereby avoiding the statement compile time. Thanks, -Adam -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Saturday, April 14, 2007 1:11 AM To: Derby Discussion Subject: Re: Derby select query speed questions Adam Bovill wrote: > Hi Olav, > > Thanks. That seems to have improved things. > > I was wondering whether or not there was a way to create one PreparedStatement from another. I have the first one that I've created and would like to clone or duplicate this, w/o needing to recompile it. > > So when I'm using a PreparedStatement, I can set the parameters w/o incurring too much of a penalty because it's already compiled? In order to answer this it would be good to know a bit more about what you are trying to achieve. Why do need several prepared statements? Note that a prepared statement is local to a connection. If you want to execute the same statement in another connection, you will have to prepare it for that connection. However, Derby has a statement cache so if the statement is lexically equal to a previous statement, the result of the previous compilation will be reused, and recompilation will not be needed. -- Øystein
