The contents of an ISAM file (table or index) have been corrupted. For C-ISAM, if you used transaction logging, you can use the isrecover program to recover the file. Otherwise, re-create the file or restore it from backup. For SQL products, use the bcheck or secheck utility to get more information on the problem and possibly correct it (use the oncheck utility (or tbcheck with IBM Informix OnLine versions 6.0 and earlier). If the utility cannot recover the table or index, you will have to re-create or restore it.