QLDB Digest Entities and Relationships

Figure 9.5 extends Figure 9.4 with entities and relationships describing QLDB digest concepts.

Figure 9.5 QLDB Digest Basic Concepts

In Figure 9.5, the DIGEST entity represents the set of all digest files requested via the Amazon QLDB console or QLDB API. The one-to-one relationship between the BLOCK and DIGEST entities reflects that each digest identifies the last block (i.e., tip of the journal) at the time the digest is requested. The one-to-many relationship between the DIGEST and HASH entities emphasizes that each digest is associated with a binary tree structure of SHA-256 hash codes including lowest level block hashes and higher level proof hashes culminating in the calculation of the digest hash at the tree summit. The one-to-many reflexive relationship between the HASH entity and itself reaffirms the Merkle tree structure among hashes.