I’m not sure that I understand the question.
If you have an AS/400 you have DB/2 .. DB/400 its name’s changed a few times.
It’s ready to use. Tables can be created using SQL or by creating a program like
description of the file (called DDS)
Tables on the 400 can be accessed in native languages – RPG/COBOL/etc or through
JDBC or ODBC.
Hope this helps