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eXtremeDB vs solidDB

eXtremeDB: Embedded in-memory and hybrid database for devices, real-time systems and time-series analytics. solidDB: Low-latency in-memory plus on-disk SQL database with HotStandby failover, sold today by UNICOM.

key differences

  • eXtremeDB is primarily a key-value database; solidDB is relational.
  • Horizontal scaling is native in eXtremeDB and manual in solidDB.
  • Only eXtremeDB has geospatial, columnar storage, encryption at rest.
  • Only solidDB has json, triggers, stored procedures.

choose extremedb for

  • +Embedded databases in network equipment
  • +Avionics and defence systems
  • +Industrial controllers and edge gateways
  • +In-process market data analytics

best at · Embedded, Edge, Time-series

choose soliddb for

  • +Telecom and network equipment control planes
  • +Embedded real-time data management in appliances
  • +Low-latency OLTP with hot-standby failover

best at · OLTP, Embedded, Cache

eXtremeDBEmbedded in-memory and hybrid database for devices, real-time systems and time-series analytics.
solidDBLow-latency in-memory plus on-disk SQL database with HotStandby failover, sold today by UNICOM.
overview
Primary model
Key-Value
Relational
Also supports
Relational, Time-Series, Columnar / OLAP, Vector
Vector
Type
Embedded library
Database engine
Status
Active
Active
Developer
McObject
UNICOM Systems (UNICOM Global)
First release
2001
1992
Latest version
9.0 (Jul 15, 2026)
201.0 (Feb 2025)
License
ProprietaryCommercial (per-product licensing)
ProprietaryProprietary commercial license
Free tier
—
—
popularity
WhichDB Score
4.0
4.7
Rank
#421
#398
GitHub stars
–
–
Stack Overflow questions
–
–
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Native
Manual
Multi-region
None
Read replicas
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Embedded, In memory, Client server, Distributed
In memory, Primary replica, Embedded, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
✓
✓
Edge
✓
—
Clouds
–
–
capabilities
Transactions
✓
✓
Joins
✓
✓
Secondary indexes
✓
✓
Full-text search
—
—
Vector search
✓
✓
Geospatial
✓
—
JSON
—
✓
Change data capture
—
—
Triggers
—
✓
Stored procedures
—
✓
Materialized views
—
—
TTL / expiry
—
—
Pub/Sub
—
—
Columnar storage
✓
—
In-memory
✓
✓
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
✓
—
Role-based access
✓
✓
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SQL (eXtremeSQL), Native C/C++ API
SQL
Client languages
C, C++, Java, Python, C#
C, C++, Java
Best for
Embedded, Edge, Time-series, Tick data
OLTP, Embedded, Cache
Add more to this comparisonNot sure either fits? Try smart match

eXtremeDB vs solidDB: FAQ

What is the difference between eXtremeDB and solidDB?

eXtremeDB: Embedded in-memory and hybrid database for devices, real-time systems and time-series analytics. solidDB: Low-latency in-memory plus on-disk SQL database with HotStandby failover, sold today by UNICOM. eXtremeDB is primarily a key-value database; solidDB is relational. Horizontal scaling is native in eXtremeDB and manual in solidDB. Only eXtremeDB has geospatial, columnar storage, encryption at rest.

When should I choose eXtremeDB over solidDB?

Choose eXtremeDB for embedded databases in network equipment; avionics and defence systems; and industrial controllers and edge gateways. Choose solidDB for telecom and network equipment control planes; embedded real-time data management in appliances; and low-latency OLTP with hot-standby failover.

Is eXtremeDB or solidDB more popular?

solidDB ranks #398 on the WhichDB Score (4.7/100) and eXtremeDB ranks #421 (4.0/100). Popularity is not fit: check the requirements that matter for your project.

Are eXtremeDB and solidDB open source?

No. eXtremeDB is proprietary, closed-source software. License: Commercial (per-product licensing). No. solidDB is proprietary, closed-source software.