1. An article of manufacture comprising a computer readable storage medium having code executed to cause operations, the operations comprising: processing a data set having a plurality of columns and records providing data for each of the columns; receiving selection of at least one predicted column for which rules are to be generated and at least one region of the selected at least one predicted column, wherein each region specifies data positions in the column; processing the data set to determine association relationships among data in records in at least one predictor column from the data set and subsequences in the selected at least one region in records of the at least one predicted column, wherein the associations are determined between data in the records in the at least one predictor column and the subsequences of the selected at least one region in the records of the at least one predicted column; and generating at least one rule from the relationships specifying a condition based on the values in the records of the at least one predictor column that predicts at least one value in the selected region of the records in the at least one predicted column.