tl;dr: This post is about how to split and process CSV files in pieces! Newline characters within fields makes it tricky, but with the help of a finite-state machine it’s possible to work around that in most real-world cases.
Comma-separated values (CSV) is perhaps the world’s most common data exchange format. It’s human-readable, it’s compact, and it’s supported by pretty much any application that ingests data. At Etleap we frequently encounter really big CSV files that would take a long time to process sequentially. Since we want our clients’ data pipelines to have minimal latency, we split these files into pieces and process them in a distributed fashion.