Summary: The "Build Your Own Database" book has been completed and is part of the "Build Your Own X" book series, which aims to teach basic computer science and software engineering topics through concise and condensed books. The book covers important database topics such as persistence, indexing, concurrency, and transactions, and follows a step-by-step approach to implement a KV store and a mini database with a SQL-like query language. Part I of the book is self-contained and can be used as a standalone book for persistent KV stores, and is also available online for free. The whole book is available as a paperback or ebook. The website build-your-own.org offers free educational software development materials and encourages readers to subscribe for updates and new books.