That is not clear. How is "compare" different from "match"? What do each of those terms really mean, for your purposes? Show a couple examples of data from each file, and what sort of output you want with regard to those examples.

Might there be duplicate lines within a given file? Do you need to keep track of the particular positions in one or both files when there is a "match" (or some particular result of "comparison"), or will it be enough just to list the data that matches/compares? Do you need to preserve or enforce a particular ordering in your output?

If the files are "very huge", then it will be very important to be very clear about what you are really trying to accomplish; having the wrong task in mind, and/or using the wrong approach, can waste a "very huge" amount of time.