protected void showDialog() {
String[] catalogs = _session.getSchemaInfo().getCatalogs();
String catalog = "";
if (catalogs != null && catalogs.length > 0) catalog = catalogs[0];
_mainDialog = new VacuumDatabaseDialog(catalog);
_mainDialog.addExecuteListener(new ExecuteListener());
_mainDialog.addEditSQLListener(new EditSQLListener(_mainDialog));
_mainDialog.addShowSQLListener(new ShowSQLListener(i18n.SHOWSQL_DIALOG_TITLE, _mainDialog));
_mainDialog.setLocationRelativeTo(_session.getApplication().getMainFrame());
_mainDialog.setVisible(true);