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Db2 for i

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by IBM · since 1988 · also known as DB2/400, DB2 UDB for iSeries, IBM i database, AS/400 database

The relational database built into IBM i (AS/400), integrated with the OS and object security.

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Overview

Db2 for i is the database integrated into the IBM i operating system on Power servers, descended from the AS/400's built-in database. There is no separate database install: tables are OS objects, security is IBM i object authority, journaling provides recovery, and both RPG record-level access and SQL work on the same files. IBM ships enhancements through twice-yearly Technology Refreshes; IBM i 7.6 TR2 (July 2026) added BYOK encryption and new SQL services. Db2 Mirror offers synchronous active-active pairs. It is low-touch and very reliable for the many mid-market manufacturers, distributors and banks on IBM i, but is tied to that platform.

Transactional apps (OLTP)

Strengths & trade-offs

Strengths

  • +Integrated with the OS: no separate install, and very little DBA work
  • +Object-level security and journaling built into the platform
  • +Same data accessible via RPG record-level I/O and modern SQL
  • +Db2 Mirror delivers synchronous active-active continuous availability
  • +Regular Technology Refreshes add SQL services and security features

Trade-offs

  • −Only runs on IBM i on Power servers
  • −Ageing RPG skills base and platform perception problems
  • −Fewer third-party tools than mainstream databases

Great for

  • +ERP and distribution systems on IBM i
  • +Regional banking and insurance back ends
  • +Manufacturing execution and warehouse systems
  • +Exposing RPG business logic and data via SQL services and REST

Think twice for

  • −Non-IBM i environments
  • −Cloud-native horizontally scaled apps
  • −Large-scale analytics

Capabilities

Native or official first-party support · 13 of 25 tracked

✓Transactions
✓Joins
✓Secondary indexes
✓Full-text search
✓JSON
✓Triggers
✓Stored procedures
✓Materialized views
✓Durable persistence
✓Compression
✓Encryption at rest
✓Role-based access
✓Time travel
–Vector search
–Geospatial
–Change data capture
–TTL / expiry
–Pub/Sub
–Columnar storage
–In-memory
–Branching
–Online schema changes
–Streaming ingest
–Offline sync
–Runs in WebAssembly

Scale & consistency

Comfortable data size
Medium · ≤ 10 TB
Horizontal scaling
None
Multi-region
Read replicas
Transactions
Full ACID
Consistency
Strong
Schema
Strict
Architecture
Single node, Multi primary, Shared storage
Query languages
SQL, SQL PL, RPG record-level access

Scales up on Power hardware; Db2 Mirror pairs two nodes active-active and PowerHA geographic mirroring covers DR.

Deployment

Self-hosted Vendor-managed cloud Serverless Embedded Edge Kubernetes operator

available on · IBM Cloud

IBM Power Virtual Server (IBM i)IBM Cloud

Ecosystem

apis & protocolsDRDA, ODBC, JDBC, IBM i Access Client Solutions
client languagesRPG, COBOL, Java, Python, JavaScript, C#, PHP

Alternatives to Db2 for i

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IBM Db2Relational45.5

IBM's enterprise RDBMS for Linux, UNIX, Windows and z/OS, with BLU columnar and pureScale clustering.

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Microsoft SQL ServerRelational71.0

Microsoft's flagship RDBMS: T-SQL, columnstore, Always On, and now native vectors and JSON.

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Oracle DatabaseRelational56.9

The enterprise heavyweight: RAC, Data Guard and a converged engine for SQL, JSON, graph and vectors.

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PostgreSQLRelational93.2

The extensible, standards-first open-source relational database.

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Progress OpenEdgeRelational20.4

Integrated RDBMS plus ABL 4GL application platform behind thousands of ERP and vertical business apps.

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MultigresRelational12.4

Alpha-stage, Vitess-inspired sharding, pooling and HA layer for unmodified PostgreSQL, led by Supabase.

ibm-db2-for-i vs multigres →

Db2 for i FAQ

What is Db2 for i?

Db2 for i is a relational database by IBM, first released in 1988. Db2 for i is the database integrated into the IBM i operating system on Power servers, descended from the AS/400's built-in database. There is no separate database install: tables are OS objects, security is IBM i object authority, journaling provides recovery, and both RPG record-level access and SQL work on the same files. IBM ships enhancements through twice-yearly Technology Refreshes; IBM i 7.6 TR2 (July 2026) added BYOK encryption and new SQL services. Db2 Mirror offers synchronous active-active pairs. It is low-touch and very reliable for the many mid-market manufacturers, distributors and banks on IBM i, but is tied to that platform.

Is Db2 for i open source?

No. Db2 for i is proprietary, closed-source software.

Does Db2 for i support ACID transactions?

Yes. Db2 for i supports full ACID transactions, with strong consistency.

Does Db2 for i scale horizontally?

Db2 for i does not scale horizontally; it runs on a single node, so you scale it up rather than out. It is comfortable at medium scale (≤ 10 TB). It supports cross-region read replicas.

How can I run Db2 for i?

You can self-host it and use the vendor's managed cloud. Managed offerings include IBM Power Virtual Server (IBM i). It is available on IBM Cloud.

What is Db2 for i best for?

Db2 for i is a strong fit for ERP and distribution systems on IBM i; regional banking and insurance back ends; and manufacturing execution and warehouse systems. Think twice for non-IBM i environments.

What are the best alternatives to Db2 for i?

Common alternatives to Db2 for i include IBM Db2, Microsoft SQL Server, Oracle Database, PostgreSQL and Progress OpenEdge. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.

How popular is Db2 for i?

Db2 for i ranks #410 of 844 databases on the WhichDB Score (4.3/100), and #131 among relational databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.