Altering IMS tables

To make changes to a table, you can issue an ALTER TABLE statement. Depending on the database access types, some attributes do not apply so changes for them are not allowed.

For a list of supported keyword attributes based on database access type, see the ALTER TABLE syntax diagrams.

For HALDB databases, you can change the data set group a table belongs to by issuing an ALTER TABLE statement with the DSGROUP keyword.

The supported changes include but are not limited to:
  • Assigning it to a different table space.
  • Changing the table sizes.
  • Changing the EDITPROC (compression exit).
  • Changing the change data capture exit.
  • Changing the columns definitions.
  • Changing the map definitions.
Restriction: If you specify any of the following keywords on the CREATE TABLE statement, you cannot change the keyword and keyword value by using the ALTER TABLE statement. To change the keyword and keyword value, you must first use the DROP TABLE statement to delete the table. Then, you must re-create the table by using the CREATE TABLE statement and specify the keyword and keyword value again.
  • The INTERNALNAMEinternalname keyword to specify the internal name of the segment type being defined.
  • DIRECT DEPENDENT | SEQUENTIAL DEPENDENT