Fast Data: Smart and at Scale

Glossary

ACID

See “What Is ACID?”.

Big Data

The volume and variety of information collected. Big data is an evolving term that describes any large amount of structured, semi-structured, and unstructured data that has the potential to be mined for information. Although big data doesn’t refer to any specific quantity, the term is often used when speaking about petabytes and exabytes of data. Big data systems facilitate the exploration and analysis of large data sets. VoltDB is not big data, but it does support analytical capabilities using Hadoop, a big data database.

CAP

See “What Is CAP?”.

Commutative Operations

A set of operations are said to be commutative if they can be applied in any order without affecting the ending state.

For example, a list of account credits and debits is considered commutative because any ordering leads to the same account balance. If there is an operation in the set that checks for a negative balance and charges a fee, then the order in which the operations are applied absolutely matters.

CRDTs

Conflict-free, replicated data-types are collection data structures designed to run on systems with weak CAP consistency, often across multiple data centers. They leverage commutativity and monotonicity to achieve strong eventual guarantees on replicated state.

Compared to strongly consistent structures, CRDTs offer weaker guarantees, additional complexity, and can require additional space. However, they remain available for writes during network partitions ...