The line command DDL for table DB2ADM.MYTABLE does not generate
ALTER TABLE DB2ADM.MYTABLE
ENABLE ARCHIVE USE DB2ADM.MYARCHIVE
However, when using HDDL this statement is generated
This is expected behavior. The ENABLE ARCHIVE statement is generated in the DDL of the archive table, in this case DB2ADM.MYARCHIVE, and not on the DDL of the original (archive-enabled) table, DB2ADM.MYTABLE.
Since HDDL will generate DDL for both tables the ALTER TABLE .. ENABLE ARCHIVE is generated for the archive table.
Use line command D (detail) to display creator/name of ARCHIVING TABLE