The RDB$CATALOG_SCHEMA system table contains the name and
    definition of each SQL catalog and schema. This table is present
    only in databases that have the SQL multischema feature enabled.
    The following table provides information on the columns of the
    RDB$CATALOG_SCHEMA system table.

                                Data
    Column Name                 Type      Summary Description

    RDB$PARENT_ID               integer   For a schema, this is the
                                          RDB$CATALOG_SCHEMA_ID
                                          of the catalog to which
                                          this schema belongs. For
                                          a catalog, this column is
                                          always 0.
    RDB$CATALOG_SCHEMA_NAME     char(31)  The name of the catalog or
                                          schema.
    RDB$CATALOG_SCHEMA_ID       integer   A unique identifier
                                          indicating whether this
                                          is a catalog or a schema.

                                          Schema objects have
                                          positive identifiers
                                          starting at 1 and
                                          increasing. Catalog
                                          objects have negative
                                          identifiers starting at
                                          -1 and decreasing. 0 is
                                          reserved.
    RDB$DESCRIPTION             list      A user-supplied description
                                of byte   of the catalog or schema.
                                varying
    RDB$SCHEMA_AUTH_ID          char(31)  The authorization
                                          identifier of the creator
                                          of the schema.
    RDB$SECURITY_CLASS          char(20)  Reserved for future use.
    RDB$CREATED                 date vms  Set when the schema or
                                          catalog is created.
    RDB$LAST_ALTERED            date vms  Set when SQL ALTER CATALOG
                                          or ALTER SCHEMA statement
                                          is used (future).
    RDB$CATALOG_SCHEMA_         char(31)  Creator of this schema or
    CREATOR                               catalog.