QLDB
Amazon Quantum Ledger Database (QLDB) is a managed ledger database management system. Its core storage architecture is an immutable and cryptographically verifiable transaction log. Unlike a blockchain DBMS where trust is distributed among participants, QLDB uses a centralized trusted authority (i.e., Amazon).
Data Model
Amazon QLDB uses a document-oriented data model Ion, which is originally developed by Amazon for internal use (now open source). It is a superset of JSON in terms of types and validation, as it provides richer data types including int, float, decimal, and timestamp. It also has the capability of performing built-in validation by user-defined Ion Struct, which not only validates data type and range but also regex expressions if specified.
Ion is a strictly value-based model and supports embedded (hierarchical) documents, but not references.
Website
Tech Docs
https://aws.amazon.com/qldb/features/
Developer
Amazon
Country of Origin
Start Year
2018