Re: Jboss/Oracle/select 1 form dual
Date: Fri, 8 May 2009 11:00:07 +0200
> Personally, I would shoot anyone who configures a pointless additional
> select statement to check connectivity; I blogged on
> couple of years ago and it has come up several times on this list. But
> that's another matter.
It may become quite hard to find the one, who is doing a "pointless additional query".
The JDBC interface contains no ping (or isAlive or similiar) method.
Connection pool implementations rely on the JDBC interface, so to check if a
is valid/usable, they can only execute standard conform methods, typically a "select null from dual".
Without a connection check, application users (and in the next steps admins
and developers) are
bored with more or less regular errors ("The first user on monday morning gets this exception")
So, a "select null from dual" is the least evil one can choose...