Physical Root Base Definition

A physical root base definition is always required, which also defined main base 0, sub base 0 and data area 0. Main base 0 is the default main base defined for the root base. Additional main bases and data areas may be defined in the physical database schema.

When no main base is defined in a database schema, main base 0 with a dynamic data area 0 will be created when creating a root base for a new database.

Main base numbers are stored in 16 high order bytes of the database entry number (LOID). The 4 high order bits are reserved for main base type identification High and low number define the range of valid main base numbers within an LOID. Usually, the values for low and high are identical with the main base number, since the lower 48 bit for numbering database entries within a main base are sufficient for most main bases.

Additional physical schemata might be defined by means of root base definitions (SDB_RootBase).