The select operator filters the incoming data stream according to the given predicate.

Parameter

• predicate: The predicate to evaluate over each incoming tuple
• heartbeatrate: The operator can send a heart beat for filtered element. Use this value to set the rate at which elements are send (1 means: Send a heartbeat for every element that is removed from the stream, i.e. the predicate is false)

Example

PQL

output = SELECT({ 
                 predicate='price > 100' 
                }, input)

CQL

SELECT * FROM input WHERE price > 100