HP OpenVMS Systems Documentation

HP COBOL
DBMS Database Programming Manual

storage schema DDL: The language used to define the physical organization of the database.

SUB-SCHEMA SECTION: The section of the Data Division that defines the subschema and keeplists to be used by the COBOL program.

subschema: A user view of a database. The subschema can include everything in the original schema DDL or any part thereof. The subschema is written using the subschema data definition language (subschema DDL).

subschema DDL: The language used to define the user view of a database.

subschema entry: An entry in the Subschema Section of the Data Division that specifies the subschema to be accessed by the COBOL program.

subschema-name: A user-defined word or nonnumeric literal that identifies a subschema.

SYSTEM-owned set: A set owned by the SYSTEM rather than by a record type. SYSTEM-owned sets have only one occurrence in the database and are used for relationships with large numbers of member occurrences or as entry points into the database.

tenancy condition: The condition, for which a truth value can be determined, that a record is a member, owner, or either, of one or more sets.

tenant: A database record that is either the owner or a member of a specific set.

tenant record: An owner or member record of a set.

UPDATE usage mode: The state of a realm in which the current run-unit may update it, as well as retrieve from it.

usage mode: The combination of the DML READY statement's allow mode and the access mode. The usage mode describes how a READY realm can be accessed. The eight usage mode combinations are:

CONCURRENT RETRIEVAL
CONCURRENT UPDATE

EXCLUSIVE RETRIEVAL
EXCLUSIVE UPDATE

PROTECTED RETRIEVAL
PROTECTED UPDATE

BATCH RETRIEVAL
BATCH UPDATE

PROTECTED and RETRIEVAL are the default.

See also access mode and allow mode.

user work area (UWA): A portion of memory assigned to the program's run unit at run time. The run unit delivers data for the DBCS to this area, and it is here the DBCS places data requested from the database for retrieval by the run unit.