METHOD AND DATA PROCESSING SYSTEM FOR ENCODING DATA STORED IN A COLUMN-ORIENTED MANNER, DATA PROCESSING PROGRAM AND COMPUTER PROGRAM PRODUCT

摘要

An improved method for encoding data stored in a column-oriented manner, comprises using a data mining algorithm (4) for finding frequent column patterns (5) among a set of data tuples, wherein each data tuple is containing a set of columns, and said data mining algorithm (4) is treating all columns and all column combinations and column ordering similarly when looking for column patterns; ordering column values occurring in said frequent column patterns (5) based on their frequencies into a prefix tree, wherein said prefix tree is defining a pattern order; sorting said data tuples according to said pattern order (7), resulting in sorted data tuples; and encoding columns of said sorted data tuples using run-length encoding.