Examples of the Update Process

The following four examples illustrate the update process.

Example 1: Altering Set and Data Set Populations

For this example, the original DASDL description looks as follows: 

D DATA SET
 (
  A ALPHA(10);
  B BOOLEAN;
  N NUMBER(6) OCCURS 15 TIMES;
 )
  POPULATION = 10000;
  S SET OF D
    KEY IS A;

To update the DASDL description with new set and data set populations, perform the following steps:

  1. Alter the DASDL statements to the following. The asterisks (*) indicate changed lines. 

    *  UPDATE;
   D DATA SET
    (
     A ALPHA(10);
     B BOOLEAN;
     N NUMBER(6) OCCURS 15 TIMES;
    )
*      POPULATION = 20000;
     S SET OF D
       KEY IS A;

  2. Compile the DASDL description.

  3. Compile the DMSUPPORT library and other database software.

  4. Create a new control file by running the SYSTEM/DMCONTROL program. Use the UPDATE option with the new description file produced in step 2.

Example 2: Changing OPTIONS, PARAMETERS, and AUDIT TRAIL Attributes

For this example, the original DASDL description looks as follows: 

OPTIONS
 (
  AUDIT,
  STATISTICS
 );
AUDIT TRAIL ATTRIBUTES
 (
  PACK = AUDPACK,
  CHECKSUM = TRUE
 );
D DATA SET
 (
  A ALPHA(5);
  B BOOLEAN OCCURS 5 TIMES;
  R REAL;
 );
RS RESTART DATA SET
 (
  X ALPHA(10);
  Y ALPHA(100);
 );

To update the DASDL description with new OPTIONS, PARAMETERS, and AUDIT TRAIL attributes, perform the following steps:

  1. Alter the DASDL statements to the following. The asterisks (*) indicate changed lines. 

    *   UPDATE;
    OPTIONS
    (
     AUDIT,
    );
*   PARAMETERS
*    (
*     CONTROLPOINT = 10,
*     SYNCPOINT = 50
*    );
    AUDIT TRAIL ATTRIBUTES
     (
      PACK = AUDPACK,
*     COPY TO TAPE AND REMOVE,
*     DUPLICATED ON TAPE VERIFY,
*     SECTIONS = 5,
*     BUFFERS = AUTOMATIC,
      CHECKSUM = TRUE
     );
     D DATA SET
      (
       A ALPHA(5);
       B BOOLEAN OCCURS 5 TIMES;
       R REAL;
      );
     RS RESTART DATA SET
      (
       X ALPHA(10);
       Y ALPHA(100);
      );

  2. Compile the DASDL description.

  3. Compile the DMSUPPORT library and other database software.

  4. Create a new control file by running the SYSTEM/DMCONTROL program. Use the UPDATE option with the new description file produeced in step 2.

Example 3: Adding New Variable-Format Parts to an Existing Variable-Format Data Set

For this example, the original DASDL description looks as follows: 

VF DATA SET
 (
  R RECORD TYPE(4);
  A ALPHA(5);
  N NUMBER(5) REQUIRED;
 ),
1: (
   X1 ALPHA(20);
   F1 FIELD(4);
  ),
3: (
   X3 BOOLEAN;
   N3 NUMBER(6);
  );
S SET OF VF KEY IS (R,A);

To update the DASDL description with new variable parts, perform the following steps:

  1. Alter the DASDL statements to the following. The asterisks (*) indicate changed lines. 

    *   UPDATE;
    VF DATA SET
     (
      R RECORD TYPE(4);
      A ALPHA(5);
      N NUMBER(5) REQUIRED;
     ),
    1: (
       X1 ALPHA(20);
       F1 FIELD(4);
       ),
*   2: (
*      A2 ALPHA(8);
*      R2 REAL;
*     ),
    3: (
       X3 BOOLEAN;
       N3 NUMBER(6);
      );
    S SET OF VF KEY IS (R,A);

  2. Compile the DASDL description.

  3. Recompile the DMSUPPORT library and some Enterprise Database Server software.

  4. Recompile any user programs that access the new variable-format parts.

Example 4: Replacing a Filler Item with New Data Items

For this example, the original DASDL description looks as follows: 

D DATA SET
 (
  A ALPHA(10);
  FILLER SIZE 100;
  B BOOLEAN;
  L IS IN D COUNTED;
  C COUNT(25);
 );

To replace a filler item with new data items, perform the following steps:

  1. Alter the DASDL statements to the following. The asterisks (*) indicate changed lines. 

    *   UPDATE;
    D DATA SET
     (
      A ALPHA(10);
*     FILLER SIZE 50;
      B BOOLEAN;
      L IS IN D COUNTED;
      C COUNT(25);
*     X ALPHA(30);
*     Y NUMBER(10) OCCURS 4 TIMES;
     );

    Note that all added items must be placed at the end of the record. Furthermore, the size of the record must not change. Thus, the filler item must be reduced in size or eliminated to produce the proper size area. For further details, refer to Update, Reorganization, and Modeling Capabilities and Limitations.

  2. Compile the DASDL description.

  3. Compile the DMSUPPORT library and other database software.

  4. Create a new control file by running the SYSTEM/DMCONTROL program. Use the UPDATE option with the new description file produced in step 2.

  5. Recompile user programs.

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