KSQL in Action: Real-Time Streaming ETL from Oracle Transactional Data

In this post I'm going to show what streaming ETL looks like in practice. My first job from university was building a data warehouse for a retailer in the UK. Back then, it was writing COBOL jobs to load tables in DB2. We waited for all the shops to close and do their end of day system processing, and send their data back to the central mainframe. From there it was checked and loaded, and then reports generated on it.