Modifying Schema Entities › Record Modifications › Modifying Record Elements

Modifying Record Elements

Types of changes

These are changes you can make to an element within a schema record:

• Adding or removing a record element
• Changing the picture or usage mode of an element

What components are affected

The record definition is affected. If data has been loaded, the data may also be affected. Subschemas in which the record is included are affected as are programs compiled from those subschemas. Access modules and SQL views that reference the record are also affected.

Steps to change the record element

To make any of the above changes when data has been loaded:

1. Using DDDL statements, create a record with a new version number and same name having the revised structure
2. Create a new schema based on the original schema with the new record
3. Validate the schema
4. Use the schema compare utility (IDMSRSTC) to generate the IDMSRSTT macro statements
5. Restructure the database
6. Complete the process by updating the original schema, regenerating affected subschemas, altering access modules, and dropping and recreating affected SQL views

Considerations

• You can replace filler elements with record elements whose total length equals that of the filler element without creating a new version of the record. The new elements are immediately reflected in the schema. The next time any programs that use that schema record are compiled, the new elements appear. Affected subschemas are flagged for regeneration.
• You should initialize any 'filler' fields or fields whose picture or usage has been changed using either RESTRUCTURE or a user-written program.
• A record element in a schema-owned record can be replaced with elements of the same name
• If you want to maintain consistency among the record version numbers in your schema:
  1. Complete all of the steps above
  2. Delete the original version of the record
  3. Modify the record using DDDL statements to change its version number

  You do not have to modify the schema.

• Non-structural changes can be made directly to schema-owned records using DDDL. For example, you can change the external picture of a record element even if it is associated with a schema.

  Note: For more information about the types of changes that can be made to schema-owned records, see the CA IDMS IDD DDDL Reference Guide.

• If you change the format (picture or usage) of an element used in a CALC or sort key, additional steps may be needed to convert the data.