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UDS/SQL

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by Fujitsu (originally Siemens) · since 1976 · also known as UDS, Universal Database System, Universelles Datenbanksystem

Fujitsu BS2000 mainframe DBMS combining a CODASYL network model with SQL on the same data.

network / navigationalrelationaldatabase engineproprietarymature
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Overview

UDS/SQL is the CODASYL-style database system for Fujitsu's BS2000 mainframe operating system, originally introduced by Siemens as UDS in 1976. Data is designed as network-model record types and sets, but the same data can also be queried relationally: programs use COBOL DML or CALL DML, and ISO SQL is available alongside. It integrates with the openUTM transaction monitor, and the UDS-D add-on processes data across BS2000 networks with distributed transactions. Fujitsu still develops it: V2.9B (November 2024) added features such as CSV bulk loading, and V2.9C manuals were published in 2026.

Transactional apps (OLTP)

Strengths & trade-offs

Strengths

  • +Network-model and relational access coexist on the same data
  • +Tight integration with openUTM for high-volume transaction processing
  • +Decades of backward compatibility for BS2000 COBOL applications
  • +Distributed transactions across hosts via UDS-D

Trade-offs

  • −Runs only on Fujitsu BS2000
  • −Niche skills market concentrated in German-speaking enterprises and public sector
  • −Proprietary and priced through enterprise contracts

Great for

  • +Core banking, insurance and public-sector systems on BS2000
  • +Maintaining CODASYL-era COBOL applications

Think twice for

  • −Anything outside a BS2000 estate
  • −Cloud-native development

Capabilities

Native or official first-party support · 5 of 25 tracked

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

Scale & consistency

Comfortable data size
Medium · ≤ 10 TB
Horizontal scaling
None
Multi-region
No
Transactions
Full ACID
Consistency
Strong
Schema
Strict
Architecture
Client server, Distributed
Query languages
COBOL DML, CALL DML, SQL

Scales on BS2000 hardware; UDS-D adds distributed processing across BS2000 hosts.

Deployment

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

Ecosystem

apis & protocolsCOBOL DML, CALL DML, openUTM
client languagesCOBOL

Alternatives to UDS/SQL

Compare all→
IDMSNetwork / Navigational6.2

CODASYL network-model mainframe database, now Broadcom's, still running decades-old COBOL systems.

uds-sql vs idms →
IBM IMSHierarchical7.7

IBM's 1960s hierarchical database and transaction manager, still running bank and airline cores on z/OS.

uds-sql vs ibm-ims →
SUPRA Server SQLRelational0.0

Cincom's mainframe relational DBMS for high-volume OLTP, the SQL half of the SUPRA family.

uds-sql vs supra-server-sql →
Software AG AdabasMultivalue (Pick)8.4

Inverted-list, multi-value mainframe database paired with Natural, run as a standalone Software AG business.

uds-sql vs adabas →
Progress OpenEdgeRelational20.4

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

uds-sql vs progress-openedge →
MultigresRelational12.4

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

uds-sql vs multigres →

UDS/SQL FAQ

What is UDS/SQL?

UDS/SQL is a network / navigational database by Fujitsu (originally Siemens), first released in 1976. UDS/SQL is the CODASYL-style database system for Fujitsu's BS2000 mainframe operating system, originally introduced by Siemens as UDS in 1976. Data is designed as network-model record types and sets, but the same data can also be queried relationally: programs use COBOL DML or CALL DML, and ISO SQL is available alongside. It integrates with the openUTM transaction monitor, and the UDS-D add-on processes data across BS2000 networks with distributed transactions. Fujitsu still develops it: V2.9B (November 2024) added features such as CSV bulk loading, and V2.9C manuals were published in 2026.

Is UDS/SQL open source?

No. UDS/SQL is proprietary, closed-source software. License: Commercial (Fujitsu BS2000 software).

Does UDS/SQL support ACID transactions?

Yes. UDS/SQL supports full ACID transactions, with strong consistency.

Does UDS/SQL scale horizontally?

UDS/SQL 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).

How can I run UDS/SQL?

You can self-host it.

What is UDS/SQL best for?

UDS/SQL is a strong fit for core banking, insurance and public-sector systems on BS2000; and maintaining CODASYL-era COBOL applications. Think twice for anything outside a BS2000 estate.

What are the best alternatives to UDS/SQL?

Common alternatives to UDS/SQL include IDMS, IBM IMS, SUPRA Server SQL, Software AG Adabas 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 UDS/SQL?

UDS/SQL has little measurable public adoption today, so it ranks near the bottom of the WhichDB Score.