Firebird vs RxDB

Firebird is a free, open-source relational database management system with ANSI SQL features. It runs on Linux, macOS, and Windows, and supports self-hosted deployment. Its multi-generation architecture generally allows readers to access data without blocking writers. SQL features include stored procedures, triggers, common table expressions, cross-database queries, and flexible transaction management. A Trace API and monitoring tables support real-time monitoring, SQL debugging, and auditing. Security controls include users and roles, GRANT and REVOKE permissions, and a database owner concept; Windows Trusted Authentication can integrate with Windows domain or Active Directory security. Deployment choices include embedded, SuperServer, SuperClassic, and Classic architectures. Backup options include online backups and dumps, as well as incremental backup with partly supported point-in-time recovery. Drivers include Java JDBC,.NET, Python, ODBC, PHP, Delphi, and C++ Builder. Free community support is available through mailing lists, alongside commercial and special support. Firebird lists versions 5.0.4, 4.0.7, and 3.0.14 as latest in their series; versions 2.5 and earlier are discontinued and no longer maintained. The enterprise subscription is €199 a month, billed from €199/month/1 servers.

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.