I was helping someone at work with a script that they had generated from a flat file. It turned out to be one long if..elsif...elsif... block. IIRC, the file was over 10MB in size. That ended up core dumping perl v5.6.0. To be fair, it may not have been the size of the file, but the number of related conditionals. I was still surprised to see perl core dump. As has been mentioned other times in this thread, an algorithm change helped this script in both runtime (given less conditionals, the script would run, but it would take about an hour) and the ability to run at all.