The application pipeline
The application pipeline of operators and streams is illustrated by the following diagram:
Operators and streams in the application pipeline
The application reads records of phone calls, and parses, filters, and enriches them, and finally writes them out to a destination file. This application is modeled on some of the examples in the Apex Library in the examples/sql
 directory. I encourage you to study these examples to gain a broader understanding of the capabilities of the Apex SQL API.
The input source is a Kafka message broker from where data in the form of CDRs (short for, Call Detail Records) is fetched by the KafkaInput
operator. The data is in the CSV format and looks like this:
13/10/2017 11:45:30 +0000,1,v,111-123-4567,222-987-6543,120
Here, the first field is a UTC timestamp, the second a unique record id, the third is v
(voice) or d
(data), denoting the type of call, the fourth and fifth fields are the origin and destination numbers, and the final field is...