Creating IMS tables

When you create an IMS table, you define a segment in the IMS database, its position in a database hierarchy, physical characteristics, and how it relates to other tables.

Consider these basic requirements when creating a new table:
  • The table name is an identifier of up to 128 characters.
  • The table name cannot be a SQL keyword or begin with DFS.
  • Provide an INTERNALNAME for non-GSAM databases.
  • Create program views that reference the INTERNALNAME on each SENSEGVIEW clause.
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 INTERNALNAME internalname keyword to specify the internal name of the segment type being defined.
  • DIRECT DEPENDENT | SEQUENTIAL DEPENDENT