sort files in /tmp not removed

I have noticed large srt* files showing up in the /tmp directory of Informix Online 5.0. The manual says they are temporary sort files. Under what circumstances are they created? Why don't they get removed? Are they kept with the idea that another query may need to use them? How do people normally clean them up? Is a cron job that removes srt* files that haven't been modified or accessed in the last 30 minutes a solution? {Hi, Elite :-)} -- Bruce Momjian | 830 Blythe Avenue root%candle.uucp@bts.com | Drexel Hill, Pennsylvania 19026 + If your life is a hard drive, | (215) 353-9879(w) + Christ can be your backup. | (215) 853-3000(h)