bbolt vs RocksDB

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.

RocksDB is an embeddable, persistent key-value store for applications that need fast storage. It stores keys and values as arbitrary byte arrays, with ordering determined by a comparator chosen by the user. Its log-structured merge design allows configuration of tradeoffs among write, read, and space amplification, and the project describes it as optimized for low-latency storage on flash drives and high-speed disks. The C++ library supports opening and closing databases, reads and writes, merging, and compaction filters. Described uses include database storage engines, application data caches, and embedded workloads. Multi-threaded compactions support databases holding multiple terabytes; the project describes an audience of application servers storing up to a few terabytes on local or remote systems. RocksDB also has a Java wrapper, RocksJava, with artifacts published through Maven. It is free and open source under either GPLv2 or Apache 2.0, at the user's choice. Building requires GCC 11 or later or Clang 10 or later for C++20 support; values must be smaller than 4 GB.