After you have registered the required database(s), the corresponding alias(es) appear in the DB Explorer tree on the left. If the Show database groups option is checked on the Environment Options | DB Explorer page, the group nodes are also displayed in the tree (alternatively, you can use the Show Database Groups item of the Database context menu, or the drop-down menu of the View Mode toolbar button for the same purpose). If necessary, you can also specify that empty schemas should be hidden in the tree: use the corresponding option available on the DB Explorer page of the Environment Options dialog.
DB Explorer displays all registered hosts and databases. Connected/disconnected hosts and databases can be easily distinguished in the tree: aliases of disconnected hosts and databases are grayed out.
To connect to a database, simply double-click its alias (or select the database alias in DB Explorer and press Enter). If the connection is successful, the database node expands into a tree of objects.
Now you can navigate within the database objects. Use SQL Assistant to get extended information about the currently selected object.
For your convenience objects having different type (for tables: Index-organized, Clustered, Object, Partitioned, Temporary), status (e.g. enabled/disabled) are displayed with different icons in Database Explorer.
Database Explorer also allows you to distinguish invalid database objects by their icons which are marked with a red cross. In the screenshot below the view 'VIEW1' is marked as invalid because of some errors in its SQL definition, or the referenced table has been dropped from the database.