As soon as the system has started you can use an existing database or to create a new one. Existing databases are listed in the browser window (to start the browser use the File menu).

To use a database you may select it from the browser or type the following statement in the Input Window:

CONNECT DatabaseName;

Note that a statement is terminated by a semicolon.

Definitions in the Input Window can be edited.

SQL keywords do not have to be entered in upper-case letters; lower-case may also be used. Tables and attribute names are case sensitive.

Once you are connected to a database, you can see the database schema and system catalog tables using the browser window.

To execute a statement present in the Input Window you must first select it and then click the Execute button. To select and execute all the statements present in the Input Window, click the Select All button and then the Execute button.

You can enter SQL statements in three ways:

The results of SQL statements are displayed in the OutputWindow. The content of this window cannot be edited, but it can be selected and copied, or saved into a file with the command Save from the File menu.

A set of select statements for the sample database SportDB is available in the page SQL By Examples of the this menu.

To exit from the system use the Quit button.

Before executing an SQL statement you can choose from the Options one or more of the following options to see in the Output Window other information:

By default the system optimize a query using a greedy search techniques. A more accurate optimization can be selected from the Options menu, but note that for complex queries the optimization process can be very time consuming! So the suggestion is to use the default choice.

The Syntax menu is an help for common SQL commands.

The ? menu shows tips about the interface.

Once you have loaded data in a new database, update statistics used by the optimizer with the command:

UPDATE STATISTICS;

 

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