unionSet (Aggregate Function)

Union multiple sets. This attribute aggregator maintains a union of sets. The given input set is put into the union set and the union set is returned.

Syntax

<OBJECT> unionSet(<OBJECT> set)

Query Parameters

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
set	The java.util.Set object that needs to be added into the union set.		OBJECT	No	Yes

Example

@info(name = 'query1')
INSERT INTO initStream
SELECT createSet(symbol) AS initialSet
FROM stockStream

@info(name = 'query2')
INSERT INTO distinctStockStream
SELECT unionSet(initialSet) AS distinctSymbols
FROM initStream WINDOW TUMBLING_TIME(10 sec);

These two queries work together to create a set object containing the distinct set of stock symbols received during a tumbling time window of 10 seconds:

1. The first query, named 'query1', processes records from the stockStream and creates an initial set of symbol values using the createSet(symbol) function. The resulting set, named initialSet, is inserted into the initStream.

2. The second query, named 'query2', processes records from the initStream and applies a tumbling time window of 10 seconds. For each window, the unionSet(initialSet) function is applied to create a single set containing the union of all initialSet values within that window. The resulting set, named distinctSymbols, contains unique stock symbols from the window and is inserted into the distinctStockStream.

In summary, distinctStockStream returns the set object which contains the distinct set of stock symbols received during a tumbling time window of 10 seconds.