If it's an Oracle 9i db you could use external tables, which is essentially sqlldr reading files as they are needed. It's quite fast as well. Just define the directory, the filename and the file format and you're done.

But that's getting off topic. I'd go with the cron vs a looping daemon. Just make sure you don't read the same file twice if the first invocation of your code doesn't complete before the next run...