Two Types of Queries—Snapshot and Continuous

Two types of queries are available, snapshot queries and continuous queries.

Snapshot Queries

Snapshot queries return data from the cache as it exists at a moment in time. A snapshot query returns a single, finite collection of entities that exist in the cache.

See The Query Language Usage and in particular, see Simple Snapshot Query Example for better understanding.

Continuous Queries

Continuous queries collect data as objects are added, deleted, or modified in the cache. That is, continuous queries work on data streaming through the query. Continuous queries continue to gather and return data when notified of changes, until you stop the query. Continuous queries use windows (explicit or implicit) to process data (snapshot queries do not). Snapshot queries are not used for event stream processing.

See Continuous Queries for more details.