Re:Faster and simpler with the command line: deep-comparing ...
by wwarnerandrew on Thursday December 06, 2018 @11:41AM
(#18619559)
OP here— good point! We actually use Athena to query these exports in S3 to debug data drift of specific export objects over time. It's quite a useful tool, I was able to go knowing basically nothing about Athena to querying gzipped newline-delimited JSON files in S3 using SQL in about an hour.
If you are going to process this amount of data, don't load it all into memory and process line by line. Also do that concurrently if you have more than one CPU core available. I've done this with ruby, python, Java, and misc shell tools like jq. Use what you are comfortable with and what gets results quickly.
One neat trick with jq is to use it to convert json objects to csv and to then pipe that into csvkit for some quick and dirty sql querying. Generally gets tedious beyond a few hundred MB. I recommend switching to Athena or something similar if that becomes a regular thing for you.