A process is provided for independently hashing and filtering a data set, such as during preprocessing. For the data set, one or more records, separately having one or more fields, may be identified. A record hash value set, containing one or more record hash values for the respective one or more records, may be generated. Generating a given record hash value may be accomplished as follows. For a given record, a hash value set may be generated, having one or more field hash values for the respective one or more fields of the given record. The record hash value for the given record may be generated based on the hash value set. A total hash value for the data set may be generated based on the record hash value set. The records of the data set may be filtered based on classification of the query that generated the records.