Apama 10.15.4 | Developing Apama Applications | Developing Apama Applications in EPL | Defining Queries | Introduction to queries
 
Introduction to queries
 
Example of a query
Use cases for queries
Delayed and out of order events
Query terminology
Overview of query processing
Overview of query application components
An Apama query is a self-contained processing element that communicates with other queries, and with its environment, by sending and receiving events. Queries are designed to be multithreaded and to scale across machines.
You use Apama queries to find patterns within, or perform aggregations over, defined sets of events. For each pattern that is found, an associated block of procedural code is executed. Typically this results in one or more events being transmitted to other parts of the system.
Note: 
If a license file cannot be found while the correlator is running, several restrictions are enforced on queries. See Running Apama without a license file.