When you open the Database painter and the ShowTableDir = 1 (the default), PowerBuilder retrieves the list of tables from the database and displays them. The list is now cached and used for future requests for the table list. The list is refreshed every 1800 seconds (30 minutes) unless you specify a different refresh rate in Database preferences.

To specify a refresh rate, set the Database variable TableListCache to the number of seconds you want to elapse before the list is refreshed.