SAP
Security Guide for IBM
i
Starting with Release 7.10, a new user concept is
introduced and will replace the classic user concept in the future. Only the
new user concept is described in this guide. However, for downward
compatibility the classic user concept is still supported. For more
information about the classic user concept, see the SAP NetWeaver Security
Guide for 7.0 in the SAP Library at:
http://help.sap.com
→ SAP NetWeaver 7.0 (2004s) → English → SAP NetWeaver Library → SAP NetWeaver Security
Guide

The IBM DB2 for i database is tightly integrated into the operating system. Therefore the database does not have its own security features but shares the security concept of the operating system. The information in this security guide is valid for both the IBM i operating system and the IBM DB2 for i database.
You need to take the measures described here on IBM i: