Defining a Database Name Table › Planning › Defining the Default Dictionary

Defining the Default Dictionary

What Is a Default Dictionary?

The default dictionary is the dictionary accessed by SQL applications, CA IDMS tools and other runtime components when none is specified through other means. For example, if the DDDL compiler is executed in batch and a dictionary is neither specified on a SIGNON statement nor a SYSIDMS parameter, the default dictionary is accessed.

Defining a Default Dictionary

The default dictionary is defined using a DBNAME statement and is identified as the default by a DBTABLE mapping rule.

By convention, the default dictionary is identified (using DBTABLE mapping rules) as the database name to which the IDMSNWKL subschema maps. Since all subschemas whose names begin with "IDMSNWK" are typically mapped in the same way, the DBTABLE mapping rule defining the default dictionary usually specifies IDMSNWK? as a subschema name.

The following statements define TESTDICT, which is comprised of segments TESTDICT and SYSMSG, as the default dictionary for the ALLDBS database name table:

  create dbtable alldbs
    subschema idmsnwk? maps to idmsnwk? dbname testdict
.
.
.
  create dbname alldbs.testdict
    segment testdict
    segment sysmsg;

Every database name table must have a default dictionary specification.