The tests in DatabasemetaDataImpl should first verify the basic ability to make a query before assuming that various features are unsupported because of exceptions thrown.

If the database is accepting connections, but throwing Exceptions on every query uPortal assumes the following:
    Supports:
        Prepared Statements: false
        Outer Joins: false
        Transactions: false (driver lies)
        {ts metasyntax: false
        TO_DATE(): false


UP-1437 made uPortal retry the tests if the database connection was completely unavailable when started.