Chapter 3 Building Physical Diagrams

Physical Options

A physical option is a parameter (included at the end of a Create statement) that defines how an object is optimized or stored in a database. Physical options are not supported by all databases, and vary by DBMS. In ASA 6, for example, you can define physical options for tables, columns, indexes, tablespaces, and databases. Other DBMSs provide options for keys, storages, and sequences.

The syntax for a physical option depends on the DBMS. For example:

DBMS	Tablespace option syntax
Oracle 6.0 or higher	Tablespace
Sybase Adaptive Server Anywhere	In

For more information about the syntax of physical options and how they are controlled in the DBMS resource file, see "Physical Options" in the DBMS Reference Guide chapter of the Advanced User Documentation .

When you change DBMS, the physical option settings are applied as far as possible to the new DBMS. If a specific physical option was selected in the model, the default value is preserved for the option in the new DBMS. Unselected physical options are reset with the new DBMS default values.

PowerDesigner allows you to set:

Default physical options for all the objects in the model (see Defining default physical options)
Physical options for a specific object, which override the default physical option values (see Defining physical options for individual objects)