When Did This Transaction Happen? PostgreSQL Snapshots, LSNs, Oracle SCNs, and More
When did a database change happen? This isn't just academic. Incremental replication must order committed changes and resume exactly without locking writers. Migration validation checks if source and target are the same state, even as both change. Audit and incident analysis reconstruct who changed data, when, and when others could see it. Application-log correlation links request timestamps with database transactions and resulting commits. It has business meaning. An editor changes a document…