problem: long transaction aborted, logs full

Anyone have any ideas on this? I tried updating a large table, adding a column to it. It ran for about an hour, then nothing. I checked the log file, and there was a message that the transaction had aborted. When it tried to roll itself back, it filled up the logs and stopped. I've shut down the db and restarted it, and it says it recovers ok, but then it immediately goes back to rolling back the long transaction, fills up the log, and stops again. I'm using: On-Line 4.00.UH1 Messages from log file: 15:22:41 INFORMIX-OnLine Initialized -- Shared Memory Initialized 15:22:41 Physical Recovery Started 15:22:42 Checkpoint Completed 15:22:42 Physical Recovery Complete: 16 Pages Restored 15:22:42 Aborting Long Transaction: pid = 0, uid = 11 After about 5 minutes ... Logical Log Files are Full -- Backup is Needed Any help would be appreciated, Thanks, John Blomberg johnb@ux1.cso.uiuc.edu