Overview of Amazon QLDB

Amazon QLDB is a fully managed, transparent, immutable, and cryptographically verifiable transaction log database. What does this really mean? If you consider running an UPDATE or DELETE statement against a typical RDBMS, what happens? If you have logging enabled, then that transaction should be stored in the logs, but there will be no record of the change within the database. It would be fairly simple for someone to make changes and for those logs to be deleted or lost (how long are transaction logs kept for before being deleted?), and then all record of that change is also lost. QLDB not only stores the latest version of a record after it's been updated or deleted but also stores all the previous versions within the database itself. Additionally, the database ensures that every new version of a record contains an algorithmic reference to the previous version, meaning that any attempt to modify a record without making a record of the change will cause...