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Empress Embedded Database

maintenance

by Empress Software Inc. · since 1979 · also known as Empress, Empress RDBMS, Empress Ultra Embedded

Veteran embedded SQL RDBMS for RTOS and Unix devices, still sold but with little visible development.

relationalembedded libraryproprietarylegacy
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maintenance. Still offered by Empress Software, but the last listed release is v10.20-H (May 2023) and public product news has been static for years.

Overview

Empress grew out of the MISTRESS project at the University of Toronto in the late 1970s and became a full-featured embeddable SQL database for real-time and embedded systems, with ports to QNX, VxWorks, LynxOS, Solaris and Windows CE. It offers ACID transactions, a SQL engine and C/C++, ODBC and JDBC interfaces, and has been used in telecom, medical, automotive and defence equipment. Empress Software still sells it, but its last widely listed release is v10.20-H (2023) and its website's news section has not moved in years. Treat it as a product for maintaining existing embedded designs rather than starting new ones.

Embedded / in-processIoT & telemetry

Strengths & trade-offs

Strengths

  • +Mature embedded SQL with ACID transactions
  • +Ports to many RTOS and Unix variants (QNX, VxWorks, LynxOS, Solaris)
  • +Long field history in telecom, medical and defence devices

Trade-offs

  • −Little visible development or community since the early 2010s
  • −Sparse public documentation and pricing
  • −Superseded in most new designs by SQLite or RaimaDB

Great for

  • +Maintaining existing embedded systems built on Empress
  • +Legacy RTOS devices needing SQL storage

Think twice for

  • −New embedded designs
  • −Server or cloud workloads
  • −Teams needing active vendor roadmaps

Capabilities

Native or official first-party support · 4 of 25 tracked

✓Transactions
✓Joins
✓Secondary indexes
✓Durable persistence
–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
–Role-based access
–Time travel
–Branching
–Online schema changes
–Streaming ingest
–Offline sync
–Runs in WebAssembly

Scale & consistency

Comfortable data size
Small · ≤ 100 GB
Horizontal scaling
None
Multi-region
No
Transactions
Full ACID
Consistency
Strong
Schema
Strict
Architecture
Embedded, Client server
Query languages
SQL

Deployment

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

Ecosystem

apis & protocolsC API, C++ API, ODBC, JDBC
client languagesC, C++, Java

Alternatives to Empress Embedded Database

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Raima Database ManagerRelational0.0

Small-footprint embedded database with SQL and network-model APIs for RTOS, edge and safety-certified devices.

empress-embedded-database vs raima-database-manager →
ITTIA DBTime-Series0.0

Embedded time-series and relational database for microcontrollers, RTOS and edge AI devices.

empress-embedded-database vs ittia-db →
SQLiteRelational75.5

The in-process SQL engine that ships in every phone, browser and OS: one file, zero servers.

empress-embedded-database vs sqlite →
eXtremeDBKey-Value4.0

Embedded in-memory and hybrid database for devices, real-time systems and time-series analytics.

empress-embedded-database vs extremedb →
Mimer SQLRelational8.6

Swedish standards-strict SQL engine built for embedded, automotive and real-time systems.

empress-embedded-database vs mimer-sql →
Microsoft AccessRelational45.8

Desktop database and forms builder bundled with Microsoft 365; still everywhere in back offices.

empress-embedded-database vs microsoft-access →

Empress Embedded Database FAQ

What is Empress Embedded Database?

Empress Embedded Database is a relational database by Empress Software Inc., first released in 1979. Empress grew out of the MISTRESS project at the University of Toronto in the late 1970s and became a full-featured embeddable SQL database for real-time and embedded systems, with ports to QNX, VxWorks, LynxOS, Solaris and Windows CE. It offers ACID transactions, a SQL engine and C/C++, ODBC and JDBC interfaces, and has been used in telecom, medical, automotive and defence equipment. Empress Software still sells it, but its last widely listed release is v10.20-H (2023) and its website's news section has not moved in years. Treat it as a product for maintaining existing embedded designs rather than starting new ones.

Is Empress Embedded Database open source?

No. Empress Embedded Database is proprietary, closed-source software.

Does Empress Embedded Database support ACID transactions?

Yes. Empress Embedded Database supports full ACID transactions, with strong consistency.

Does Empress Embedded Database scale horizontally?

Empress Embedded Database does not scale horizontally; it runs on a single node, so you scale it up rather than out. It is comfortable at small scale (≤ 100 GB).

How can I run Empress Embedded Database?

You can self-host it and embed it in your application.

What is Empress Embedded Database best for?

Empress Embedded Database is a strong fit for maintaining existing embedded systems built on Empress and legacy RTOS devices needing SQL storage. Think twice for new embedded designs.

What are the best alternatives to Empress Embedded Database?

Common alternatives to Empress Embedded Database include Raima Database Manager, ITTIA DB, SQLite, eXtremeDB and Mimer SQL. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.

Is Empress Embedded Database still maintained?

Empress Embedded Database is in maintenance mode. Still offered by Empress Software, but the last listed release is v10.20-H (May 2023) and public product news has been static for years.

How popular is Empress Embedded Database?

Empress Embedded Database ranks #456 of 844 databases on the WhichDB Score (2.8/100), and #141 among relational databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.