Hello World to Amazon Quantum Ledger Database

When I first hear Amazon Quantum Ledger Database, the following two words are very misleading.

Quantum: transaction can be in one of many possible states, which one is unknown — until fixed by observation (I get this explanation from the last video below)

Ledger database: not DLT (distributed ledger technology, usually blockchain), but ledger means system of records

Actually, it is not related to quantum computing and not a blockchain offering. It is a centralized ledger database (use case is where data integrity, completeness, change tracking and verifiability are critical: e.g. credit and debit transactions, movement between carriers and across borders). The following article clarifies this:

5 Myths of AWS Quantum Ledger Database (QLDB)

Quick start

Follow Amazon tutorial

Amazon QLDB Node.js tutorial

Notes

Sample application used here is at

GitHub - aws-samples/amazon-qldb-dmv-sample-nodejs: A DMV based example application which…

Step 1: Constants.ts is at src/qldb, CreateLedger.ts is at src. then execute

export AWS_REGION=us-east-1
node dist/CreateLedger.js

Step 4: query table

Step 5: modify documents

The vehicle registrations have been transferred to other owners.

Step 6: view the revision history

Appendix