Import 2 column CSV files to some sort of DB.... preliminary planning
A while ago I wrote a couple of blog posts on loading logfiles into SQLite for analysis. This is an incredibly easy database to use, zero administration, bindings to any language you can think of (e.g. Python and Tcl/Tk as well as exotic ones like OCaml) supports a decent subset of SQL for complex reporting and can handle surprisingly large datasets (millions of rows). You don't say what OS you're on, but on Linux it's just a yum or an apt-get away. I'd definitely choose it over MySQL for this kind of work.