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Fjall vs TidesDB

Fjall: Log-structured, embeddable key-value engine in pure Rust with keyspaces and transactions. TidesDB: Young C storage-engine library: transactional LSM with MVCC, column families and TTL.

key differences

  • Licensing: Fjall is open source (permissive) (MIT or Apache License 2.0); TidesDB is open source (copyleft) (Mozilla Public License 2.0).
  • Fjall is built for larger datasets (≤ 10 TB) than TidesDB (≤ 100 GB).
  • Only TidesDB has ttl / expiry.

choose fjall for

  • +Write-heavy storage inside Rust services
  • +Embedded time-series or log storage
  • +Replacing RocksDB bindings in Rust code

best at · Embedded, Time-series, Metadata

choose tidesdb for

  • +Building custom database engines
  • +Embedded transactional storage in C/C++ systems
  • +Experimenting with alternatives to RocksDB

best at · Embedded, OLTP

FjallLog-structured, embeddable key-value engine in pure Rust with keyspaces and transactions.
TidesDBYoung C storage-engine library: transactional LSM with MVCC, column families and TTL.
overview
Primary model
Key-Value
Key-Value
Also supports
–
Wide-Column
Type
Embedded library
Embedded library
Status
Active
Active
Developer
Marvin Jäger and contributors
TidesDB (Alex Gaetano Padula)
First release
2023
2024
Latest version
3.1.13 (Oct 25, 2026)
10.2.1 (Oct 12, 2026)
License
Open source (permissive)MIT or Apache License 2.0
Open source (copyleft)Mozilla Public License 2.0
Free tier
✓
✓
popularity
WhichDB Score
15.4
13.7
Rank
#215
#249
GitHub stars
2.4K
606
Stack Overflow questions
–
–
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Small (≤ 100 GB)
Horizontal scaling
None
None
Multi-region
None
None
ACID
Full
Full
Consistency
Strong
Strong
Schema
Schemaless
Schemaless
Architecture
Embedded
Embedded
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
Rust API
C API
Client languages
Rust
C, C++, Go, Rust, Python, Java
Best for
Embedded, Time-series, Metadata
Embedded, OLTP
Add more to this comparisonNot sure either fits? Try smart match

Fjall vs TidesDB: FAQ

What is the difference between Fjall and TidesDB?

Fjall: Log-structured, embeddable key-value engine in pure Rust with keyspaces and transactions. TidesDB: Young C storage-engine library: transactional LSM with MVCC, column families and TTL. Licensing: Fjall is open source (permissive) (MIT or Apache License 2.0); TidesDB is open source (copyleft) (Mozilla Public License 2.0). Fjall is built for larger datasets (≤ 10 TB) than TidesDB (≤ 100 GB). Only TidesDB has ttl / expiry.

When should I choose Fjall over TidesDB?

Choose Fjall for write-heavy storage inside Rust services, embedded time-series or log storage and replacing RocksDB bindings in Rust code. Choose TidesDB for building custom database engines, embedded transactional storage in C/C++ systems and experimenting with alternatives to RocksDB.

Is Fjall or TidesDB more popular?

Fjall ranks #215 on the WhichDB Score (15.4/100) and TidesDB ranks #249 (13.7/100). Popularity is not fit: check the requirements that matter for your project.

Are Fjall and TidesDB open source?

Yes. Fjall is open source. License: MIT or Apache License 2.0. Yes. TidesDB is open source. License: Mozilla Public License 2.0.