bbolt vs eXtremeDB

bbolt is a maintained fork of Bolt, providing Go applications with an embedded key-value store instead of a full database server. It keeps the database in one file, representing a consistent snapshot of its data. Key/value pairs are arranged in buckets, which can be nested, and bucket keys are stored in byte-sorted order. The library supports serializable ACID transactions: one read-write transaction at a time, alongside multiple concurrent read-only transactions.

A read-only transaction can create a consistent hot backup without blocking other database reads and writes. bbolt exposes operation statistics that can be logged or sent to a service such as statsd. The project describes it as a fit for read-intensive workloads and range scans, while warning that random writes can be slow. The database file has an exclusive write lock, so multiple processes cannot share it for writing; read-only mode permits multiple readers. The project documents gomobile bindings for iOS and Android, as well as Windows, macOS and Linux support. It is free under the MIT license, with no paid support plan listed.

eXtremeDB is an in-memory database system designed for embedded devices and applications. It can combine in-memory and persistent storage within one database system. Interfaces include native APIs, REST, SQL, ODBC, and JDBC, with language APIs for C/C++, Java, Python, C#, Go, and Rust. For time-series data, a sequence type provides columnar storage. Distributed options include High Availability, Cluster, and Active Replication Fabric for replication across IoT tiers. Network communications can use TLS/SSL with OpenSSL or wolfSSL. Technical specifications list maximum database sizes of 4 GB on 32-bit architectures and 18.4 exabytes on 64-bit architectures. eXtremeDB supports Android, iOS, Linux, macOS, and Windows, and can be self-hosted. Evaluation downloads are listed for Linux, macOS, and Windows; custom trial packages can be requested for other platforms. McObject offers annual engineering support contracts that include software updates and a 50 percent discount on major upgrades. Commercial licensing is paid, with pricing available on request, and a 60-day trial is listed.