Format

      DEFINE  COLLECTION collection-name

              [ DESCRIPTION IS /*text*/ ]   [ AUDIT IS /*text*/ ] .

1  –  Parameters

1.1  –  collection-name

    Specifies the collection you are creating.

1.2  –  text

    Adds information. Within the DESCRIPTION clause, this is
    information documenting the collection; within the AUDIT clause,
    it is a history list entry. Valid delimiters are /* */ or double
    quotation marks (" ").

    You can use Japanese to document comments in the DESCRIPTION or
    AUDIT clause for a field. To do this, use the SET CHARACTER_SET
    command, and set the character_set of the session to DEC_KANJI.

2  –  Description

    The DEFINE COLLECTION command creates a collection. A collection
    allows you to view and manipulate a group of related elements
    that make up a particular system or subsystem.

    Because a collection is a controlled element, you use the DEFINE
    COLLECTION command to create the initial version of a collection.
    Use the RESERVE and REPLACE commands to create new versions.

    Before you issue the DEFINE COLLECTION command, you must create
    and set a context. The SHOW CONTEXT command indicates whether you
    have completed these steps.

    Because all elements in a collection hierarchy are children
    of the top collection, you can issue commands that affect the
    entire hierarchy with the /DESCENDANTS or /CLOSURE qualifiers.
    Because most elements in a collection hierarchy are also children
    of smaller subcollections beneath the top collection, you can
    also issue commands that affect only one subcollection and its
    children.

    To create a collection hierarchy, issue the DEFINE COLLECTION
    command immediately after the SET CONTEXT command. SET CONTEXT
    implicitly sets the collection you define as the top collection
    in the hierarchy, provided that you did not set a top collection
    within the DEFINE CONTEXT command.

    To extend the hierarchy beneath the top collection, you issue the
    following commands:

    1. DEFINE COLLECTION to create the collections that participate
       in the hierarchy. This command attaches all collections in the
       first level beneath the top collection.

    2. DETACH FROM COMPOSITE to detach those collections destined for
       lower levels in the hierarchy from the first level beneath the
       top collection.

    3. RESERVE and ATTACH TO COMPOSITE to reserve collections in each
       successive level and attach their immediate children.

    4. REPLACE to store in a partition the elements you have created.

3  –  Examples

    1.CDO>  DEFINE COLLECTION REGIONAL_SALES.

      In this example, the DEFINE COLLECTION command creates the
      REGIONAL_SALES collection.

    2.CDO>  DEFINE PARTITION FIRST_BASELEVEL.          1
      CDO>  DEFINE CONTEXT DEVELOPMENT_CONTEXT
      cont>   BASE_PARTITION FIRST_BASELEVEL.
      CDO>  SET CONTEXT DEVELOPMENT_CONTEXT
      CDO>  DEFINE COLLECTION COMPILER_C.              2
      CDO>  RESERVE COLLECTION COMPILER_C
      CDO>  DEFINE COLLECTION FRONT_END.               3
      CDO>  DEFINE COLLECTION BACK_END.
      CDO>  DEFINE COLLECTION PARSER.

      CDO>  DEFINE FILE_ELEMENT MCS_BINARY PARSER_TABLES
      cont>   STORETYPE EXTERNAL
      cont>   MCS_STOREDIN IS "CDD$DISK:[SMITH]PARSER_TABLES.DAT".
      cont>   END FILE_ELEMENT MCS_BINARY PARSER_TABLES.

      CDO>  DETACH COLLECTION PARSER FROM COMPILER_C   4
      CDO>  DETACH FILE_ELEMENT PARSER_TABLES FROM
      cont>   COMPILER_C
      CDO>  RESERVE COLLECTION FRONT_END
      CDO>  ATTACH COLLECTION PARSER TO FRONT_END      5
      CDO>  RESERVE COLLECTION PARSER
      CDO>  ATTACH FILE_ELEMENT PARSER_TABLES TO PARSER
      CDO>  REPLACE COLLECTION /CLOSURE=TO_TOP PARSER

      The successive DEFINE COLLECTION commands in this example
      participate in the creation of a collection hierarchy.

      1  DEFINE PARTITION, DEFINE CONTEXT, and SET CONTEXT commands
         allow you to control elements.

      2  DEFINE COLLECTION command creates the collection; this
         command also sets COMPILER_C as the top collection because
         the current context, DEVELOPMENT_CONTEXT, does not have a
         top collection defined.

      3  DEFINE COLLECTION commands create subcollections FRONT_END,
         BACK_END, and PARSER and file element PARSER_TABLES under
         collection COMPILER_C.

      4  DETACH commands detach PARSER and PARSE_TABLES from
         collection COMPILER_C.

      5  ATTACH commands attach PARSER under subcollection FRONT_END
         and PARSE_TABLES under subcollection PARSER.