1. A computer implemented method for performing a clean operation on an input table having an input table name, comprising: receiving at least one rule definition, wherein each rule definition indicates a find criteria, a replacement value, and an input data column in the input table; searching, for each rule definition, the input data column for any fields that match the find criteria; determining whether the rule definition specifies an output table; and in response to determining that the rule definition does not specify an output table, directly inserting, for each rule definition, the replacement value in the fields in the input data column that match the find criteria, wherein subsequent applications of additional rule definitions applied to the same input data column operate on replacement values inserted in the input data column in previously applied rule definitions.