1. A method for efficient indexing of error tolerant set containment, comprising: obtaining a frequency threshold and a query set; determining all tokens or token sets within the query set; finding all minimal infrequent tokens or all minimal infrequent tokens sets of data records and using said minimal infrequent tokens or minimal infrequent tokens sets to build an index; processing the minimal infrequent tokens or minimal infrequent tokensets in a fixed order; and determining a collection of signatures for each minimal infrequent token or token set.