Physical Database DDL Statements › DBNAME Statements › Entity Currency › Usage

Usage

What the DBNAME Statement Does

Each DBNAME statement defines an entry in the database name table. Each DBNAME statement defines a database name that may be specified in a BIND RUN-UNIT or SQL CONNECT statement unless FOR FOR UTILITY USE ONLY is specified. If UTILITY USE ONLY is specified, the database name can only be used for administrative purposes.

Restrictions on Names

The following restrictions apply to database name definitions:

• The database name must be different from any segment included in a DMCL associated with the database name table unless the segment is included in the database name definition.
• The names of all areas associated with segments added to the database name definition must be unique unless FOR UTILITY USE ONLY is specified. For example, you cannot have an area named EMP_AREA in segments EMPSEG and PROJSEG if both segments are included in a database name definition.

These restrictions are checked at runtime. If violated, the database name is marked in error and no transaction will be allowed to access it.

Using Wildcards for Mapping Subschemas

When you specify a subschema name, you can use a question mark (?) to indicate any character. Each question mark in ssc-name-1 will match any character in the corresponding position of a subschema name passed on the BIND RUN-UNIT statement. For example, an ssc-name-1 of EMP??T? will match all 7-character subschema names beginning with EMP and having a "T" as the sixth character.

Each question mark in ssc-name-2 will preserve the character in the corresponding position of the subschema name passed on the BIND. For example, an ssc-name-2 of EMP??P? will replace the first three characters and the sixth character of the subschema name passed on the bind statement with "EMP" and "P" respectively. The remaining characters of the subschema name remain unchanged. If ssc-name-2 is ????????, the subschema name passed on the bind statement remains unchanged.

Mapping Sequence Is Important if Using Wildcards

Subschema mappings are searched from top to bottom until a match is found on ssc-name-1. Therefore, you should list the most specific subschema mapping first and the least specific last. For example:

add subschema emp???? maps to emp????
 .
 .
 .
add subschema ???????? maps uses dbtable mapping