JBoss keeps sending select 'hello' from dual
Date: Thu, 23 Oct 2008 16:33:38 -0400
While investigating some performance issues on two unrelated databases one of the odd things we found was a huge number of "select 'hello' from dual"
statements hitting the databases (as in over a million/hour).
Further investigation leads us to believe that this is a standard feature of JBoss connection pooling and the method it uses to check if a connection is still alive but we couldn't find any real details on it.
Just wondering if anyone else has encountered this before and can point me to additional information or any way of reducing its impact.