Open-Source Databases · armink

FlashDB

FlashDB is a lightweight embedded database written in C that provides key-value and time-series storage with minimal RAM footprint. It is optimized for IoT and embedded systems where flash memory is the primary storage medium and resource constraints are critical.

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Source: GitHub — github.com/armink/FlashDB

2.8k

GitHub stars

554

Forks

Primary language

Apache-2.0

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	armink/FlashDB
Owner	armink
Primary language	C
License	Apache-2.0 — OSI-approved
Stars	2.8k
Forks	554
Open issues	190
Latest release	2.2.0 (2026-03-23)
Last updated	2026-06-12
Source	https://github.com/armink/FlashDB

What FlashDB is

FlashDB implements dual-mode storage: KVDB for non-relational key-value pairs and TSDB for time-sequenced data, with wear leveling, power-off protection, and multi-partition support. Written in C with negligible RAM overhead, it achieves insertion rates of 0.37–250 ms per record and query times of 0.11–1.77 ms per record depending on flash type.

Quickstart

Get the FlashDB source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/armink/FlashDB.git2cd FlashDB3# follow the project's README for install & configuration

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Best use cases

IoT Sensor Data Logging

Time-series storage of environmental metrics (temperature, humidity) and health data from wearables where insertion speed and compact footprint are essential.

Embedded Device Configuration

Persistent storage of product parameters and user settings in resource-constrained firmware where minimal RAM is available and wear-leveling extends flash lifespan.

Edge Device Event & Alarm Logging

Efficient recording of historical operation logs and abnormal alarms on remote or battery-powered devices with minimal storage overhead and fast query performance.

Implementation considerations

Porting required: FlashDB integrates with the target MCU's flash HAL; porting documentation is available but adaptation to your specific platform is necessary.
Partition strategy: Multi-partition support reduces retrieval time; design partitioning based on expected data volume and query patterns.
Wear-leveling configuration: Built-in but requires understanding of flash characteristics (W25Q64 vs. STM32F2 on-chip flash) to optimize flash lifespan.
Firmware upgrade path: Incremental upgrade support for KVDB exists; plan pre-upgrade data validation and rollback strategy.
Power-loss handling: Power-off protection is supported; confirm implementation meets your system's power-cut scenarios and recovery requirements.

When to avoid it — and what to weigh

Complex Relational Queries Required — FlashDB is not a relational database; it does not support SQL joins, complex WHERE clauses, or multi-table transactions. Use a traditional RDBMS if complex relationships are needed.
High Concurrent Write Workloads — No documentation provided on concurrent write handling or locking mechanisms; thread-safety guarantees are not clearly stated. Avoid for high-concurrency server workloads.
Large-Scale Enterprise Data — FlashDB is purpose-built for embedded systems with limited storage (kilobytes to low megabytes). Not intended for enterprise databases with gigabytes or terabytes of data.
Network Replication or Clustering — No built-in replication, clustering, or distributed consensus mentioned. If data must be synchronized across multiple devices, a different architecture is required.

License & commercial use

Apache License 2.0 (Apache-2.0) is a permissive, OSI-approved open-source license. It permits use, modification, and distribution in both commercial and proprietary contexts, provided that the original copyright notice, LICENSE file, and a copy of changes (NOTICE file) are retained.

Commercial use is permitted under Apache-2.0. You may embed FlashDB in proprietary firmware or products without source-code disclosure, provided you include a copy of the Apache-2.0 LICENSE and note any modifications. Consult legal counsel if your product has specific compliance requirements (medical, automotive, etc.).

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Strong
License clarity	Clear
Deployment complexity	Moderate
DEV.co fit	Strong
Assessment confidence	High

Security considerations

No explicit security audit, penetration test results, or vulnerability disclosure policy mentioned in provided data. FlashDB offers power-off protection and wear-leveling but does not implement encryption, authentication, or access controls. For sensitive data (e.g., credentials, PII), consider layering encryption at the application level. Review the GitHub security policy and closed security issues before deployment in security-critical products.

Alternatives to consider

SQLite

Full-featured SQL database with transaction support; larger footprint (~500 KB) but offers relational queries, ACID guarantees, and broader compatibility. Use if complex queries or portability across platforms is critical.

LittleFS

Lightweight filesystem focused on flash wear-leveling and power-loss safety, but not a database; requires custom key-value or serialization logic. Choose if you need file-level abstraction rather than a structured data layer.

Cassandra (embedded/lightweight variant)

Distributed time-series database with replication; much heavier footprint and complexity. Use only if cross-device replication and high availability are mandatory.

Software development agency

Build on FlashDB with DEV.co software developers

FlashDB is a solid choice for resource-constrained IoT devices and sensor logging. However, confirm porting requirements, concurrency model, and security posture with the maintainers or source review before committing to production.

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FlashDB FAQ

Can I use FlashDB on non-MCU platforms?

FlashDB is designed for embedded systems with flash storage. Use on general-purpose Linux/Windows requires porting or abstraction. Not recommended for server or desktop deployment.

Does FlashDB support encryption?

No built-in encryption mentioned in the provided documentation. Implement encryption at the application layer if sensitive data protection is required.

What is the maximum database size?

Not clearly stated in provided data. FlashDB scales with available flash memory; multi-partition support helps distribute large datasets. Contact maintainers or test on your target platform.

Is FlashDB thread-safe?

Concurrency and locking behavior not documented in the provided data. Assume single-threaded or serialized access unless explicitly confirmed by review of source or maintainer feedback.

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