DELAY()
A delay window holds events for a specific time period that is regarded as a delay period before processing them.
Syntax
WINDOW DELAY(delay <INT|LONG|TIME>)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| delay | The time period (specified in sec, min, ms) for which the window should delay the events. | INT LONG TIME | No | No |
Example
CREATE WINDOW delayWindow(symbol string, volume int) DELAY(1 hour);
CREATE STREAM PurchaseStream(symbol string, volume int);
CREATE STREAM DeliveryStream(symbol string);
CREATE SINK STREAM OutputStream(symbol string);
@info(name='query1')
INSERT INTO delayWindow
SELECT symbol, volume
FROM PurchaseStream;
@info(name='query2')
INSERT INTO OutputStream
SELECT delayWindow.symbol
FROM delayWindow JOIN DeliveryStream
ON delayWindow.symbol == DeliveryStream.symbol;
In this example, purchase events that arrive in the PurchaseStream stream are directed to a delay window. At any given time, this delay window holds purchase events that have arrived within the last hour.
These purchase events in the window are matched by the symbol attribute, with delivery events that arrive in the DeliveryStream stream. This monitors whether the delivery of products is done with a minimum delay of one hour after the purchase.