Disclosed is a method, system, program, and data structure for performing a clean operation on an input table. The input table to clean is indicated in an input data table name. At least one rule definition is processed to clean the input table. Each rule definition indicates a find criteria, a replacement value, and an input data column in the input table. For each rule definition, the input data column is searched for any fields that match the find criteria. The replacement value for the particular rule definition is inserted in the fields in the input data column that match the find criteria. Subsequent applications of additional rule definitions applied to the same input data column operate on replacement values inserted in the input data column during previously applied rule definitions.