SQLite

SQLite is a C-language library that provides a self-contained, serverless, zero-configuration, transactional SQL database engine. It is designed to be embedded into applications, rather than run as a separate database server. An entire database is stored in a single cross-platform file, which simplifies distribution, backup, and sharing of data.

The project was created by D. Richard Hipp and first released in 2000. SQLite is in the public domain, allowing broad use without licensing restrictions. The engine is lightweight and portable, including the compiler, query planner, and a small set of SQL capabilities that run inside the host application.

Technical overview: SQLite operates as an in-process library. It handles parsing, optimization, and execution of SQL statements, and manages database files using a B-tree structure with pages. Transactions are atomic and durable, typically implemented using a rollback journal or a write-ahead log. The database supports standard SQL features such as tables, indices, triggers, and views, and offers various extensions and pragmas to tailor behavior. It is frequently used as an embedded database within software applications rather than as a standalone server.

Usage and prevalence: SQLite is widely adopted across mobile, embedded, and desktop software. It is commonly used as the default database in mobile platforms and in applications needing a lightweight, easily distributable data store. Its portability and simplicity make it a popular choice for development, testing, and small-to-medium scale data storage.

Limitations and considerations: Since SQLite is embedded and file-based, it is best suited for workloads with moderate write concurrency and centralized access. It does not provide a client-server architecture, built-in user management, or extensive multi-user features. For high-load, highly concurrent, or centrally managed deployments, a server-based RDBMS may be more appropriate.