DB2 for i

DB2 for i (formerly DB2/400) is the relational database management system integrated into IBM i (OS/400). Unlike most server platforms where the database is a separate application installed on top of the OS, DB2 for i is part of the IBM i operating system itself. This integration means no separate database licensing, no separate database installation, and tight OS-level optimizations for database operations. DB2 for i supports standard SQL (including modern SQL features), native file system operations, journal-based change data capture, and both record-level and set-level data access. The integration with IBM i's object-based storage model means tables are stored as physical files with journal control and security applied at the OS level. DB2 for i is one of the most frequently cited reasons organizations remain on the IBM i platform: the database reliability, performance for transaction processing, and total cost of ownership are difficult to replicate on other platforms.