Database Picker does not close database connection

We have implemented a database picker with a connection to an external database. In principal the picker works fine, except that it doesn't close the Database|UNIX/Oracle Sessions. With every select, we get an additional Linux session and in the end, the maximum number of allowed sessions is reached.

We actually have to stop Jira or kill the processes on the database server (which I can't).

It would be nice if database picker will close that connection after use