Too late to meaningfully join any of them.

Power Query is a component of Excel and Power BI.

The first is the result when I extracted all lines with my nick in them from the csv, stored with the best compression around. The second is where to get the csv - and a lot of communities have been archived there, like it says.

Power Query can search line by line without loading a file much bigger than your RAM.

That could be a big zip file. They’ve got nothing better?