I was working with a VOIP startup, and they needed to find some unique numbers in their CDR's (call detail records, basically a CSV list of calls made, duration

I was working with a VOIP startup, and they needed to find some unique numbers in their CDR's (call detail records, basically a CSV list of calls made, duration, etc.) . Loading the file into Excel took literally minutes as Excel tried to parse every field. It bogged down a 16GB RAM machine. Using awk and uniq, the total run time of getting a solution , including reading the many MB of files and generating a summary into another file, was about 6 seconds.