On software and hardware techniques of data engineering

Methods are discussed to enhance the efficiency and speed of data compression techniques in DBMS (database management systems). Arithmetic coding utilizes the skewness of character distribution by assigning larger intervals (code ranges) to characters having higher probabilities of occurrence. A scheme is presented which effectively increases the code ranges of individual characters by splitting the interval assignment into different groups. This decreases the rate of interval narrowing and hence improves the compression efficiency. Hardware assistance for arithmetic and tree-based coding is also discussed and high-speed VLSI algorithms for data compression are presented. The proposed algorithms give rates that are an order of magnitude faster than currently attainable encoding speeds