The author discusses the concept of durability in databases, emphasizing the importance of a write-ahead log (WAL) for ensuring data safety. Despite the necessity of a WAL in most databases, the author explores the idea of achieving durability without it, highlighting the potential risks of such an approach. The post delves into optimizing durable writes by utilizing an append-only log and periodically writing the entire database structure to disk. Additionally, the author touches on filesystem and disk bugs, the need for checksumming data, and the significance of a WAL in implementing aspects of ACID transactions and logical replication. Overall, the post serves as a thought-provoking exploration of durability in databases.
https://notes.eatonphil.com/2024-07-01-a-write-ahead-log-is-not-a-universal-part-of-durability.html