bbolt vs RxDB

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.

RxDB is a NoSQL database for JavaScript that runs inside an application and keeps data locally on the client. It supports offline operation, including applications that run entirely without a backend. When synchronization is needed, its Sync Engine connects to backends including RxServer, GraphQL, Firebase, Supabase, MongoDB, NATS, HTTP, CouchDB, WebRTC, Appwrite, Google Drive, and Microsoft OneDrive. Observable queries update as stored data changes. RxDB runs in browsers, mobile apps, desktop applications, and servers, with storage options including LocalStorage, IndexedDB, OPFS, SQLite, Node.js Filesystem, Expo Filesystem, MongoDB, and FoundationDB, among others. Collections use JSON Schema with validation and migration support. An encryption plugin protects locally stored documents with a password in browsers, React Native, and Node.js. The free tier is under Apache 2.0 and allows up to 13 open collections in parallel. Free users get community support through GitHub and Discord; Enterprise includes an SLA with a 24-hour first response. Pro costs $99 a month billed annually, and Pro Plus costs $239 a month billed annually.