Subdividing a Sequence: Exercise

Set a subet of events to occur within a specific amount of time independent of the overall timing.

1. Replace the Query statement in the Queries tab with the following text (or copy the text from PatternMatchingCCL.txt between the lines "-- Pattern Matching Code Block 3" and "-- Pattern Matching Code Block 4"):

   /* Match a pattern indicating front running:
        Row with customer order
        (from either of two streams)
        Row with placed order for broker
        Row with placed order for customer
        (last two within 2 secs) */
   
   INSERT INTO StreamFraudAlerts
   SELECT "Front Running", Broker.OrderId, Broker.Symbol, Broker.Customer
   From StreamPhoneOrders Phone, StreamWebOrders Web, 
   	StreamPlacedOrders Broker, StreamPlacedOrders Cust
   MATCHING [10 SECONDS: Phone || Web, [2 SECONDS: Broker, Cust]]
   ON Phone.Broker = Web.Broker = Broker.Customer = Cust.Broker 
   	AND Phone.Symbol = Web.Symbol = Broker.Symbol = Cust.Symbol
   WHERE Phone.OrderId = Cust.OrderId 
   	OR Web.OrderId = Cust.OrderId;
   

   The only change to this Query statement from the previous activity is in the MATCHING clause. The entire pattern must still happen within 10 seconds, but now the row arriving on Cust must also arrive within two seconds of the row arriving on Broker.

2. Start the project and let it run to completion.
3. Examine the StreamFraudAlerts stream viewer:

   
   
   

   Now only a single sequence of rows matches the pattern and produces an output row. Look through the other viewers to ensure that you can identify the rows that matched the pattern.

4. Stop the project.