A comparison of software defects in database management systems and operating systems

An analysis of software defects reported at customer sites in two large IBM database management products, DB2 and IMS, is presented. The analysis considers several different error classification systems and compares the results to those of an earlier study of field defects in IBM's MVS operating system. The authors compare the error type, defect type, and error trigger distributions of the DB2, IMS, and MVS products; show that there may exist an asymptotic behavior in the error type distribution as a function of a defect type; and discuss the undefined state errors that dominate the error type distribution.