Alternatively, you can use a connection pool at supports the JDBC4 Connection.isValid() method, such as the one included with Bitronix JTA. Of course, you have to use a transaction manager in the case of Bitronix, but that's not a bad thing. In theory, the JDBC4 isValid(), if implemented correctly by the driver, should be much less expensive than a test query (which still has to be parsed and executed). Derby does implement the isValid() method.
Brett On Fri, Apr 13, 2012 at 11:48 PM, Martin Lichtin <[email protected]> wrote: > Hi > Implementations of connection pooling typically use a "test query" to > first check > whether a connection is still valid before sending the actual query across. > A test query looks like > SELECT SYSDATE FROM DUAL (eg. PostgreSQL or Oracle) > or > SELECT 1 (eg. Ingres) > > What is a suitable test query for Derby? I couldn't find one off-hand. > > Thanks > Martin >
