Database Reference
In-Depth Information
Structured records
The first three database features we looked at are commonly found in distributed data
stores. However, databases like Riak and Voldemort are purely key-value stores; these data-
bases have no knowledge of the internal structure of a record that's stored at a particular
key. This means useful functions like updating only part of a record, reading only certain
fields from a record, or retrieving records that contain a particular value in a given field are
not possible.
Relational databases like PostgreSQL, document stores like MongoDB, and, to a limited
extent, newer key-value stores like Redis do have a concept of the internal structure of their
records, and most application developers are accustomed to taking advantage of the possib-
ilities this allows. None of these databases, however, offer the advantages of a masterless
distributed architecture.
In Cassandra, records are structured much in the same way as they are in a relational data-
base—using tables, rows, and columns. Thus, applications using Cassandra can enjoy all
the benefits of masterless distributed storage while also getting all the advanced data mod-
eling and access features associated with structured records.
