Database models

A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a chain (viz. linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are resistant to alteration because, once recorded, the

database model invented by Charles Bachman

tree-like database model

database management system

database which utilizes structure of discrete mathematical graphs to store and search data

generic structure of a database type, for instance relational

combining data from different sources and providing a unified view

database management system that stores data tables by column rather than by row

database stored as an ordinary unstructured file (flat file)