Computer Science and Engineering, Department of


First Advisor

Peter Revesz

Date of this Version



A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Computer Science, Under the Supervision of Professor Peter Revesz. Lincoln, Nebraska: April, 1997

Copyright (c) 1997 YiMing Li


In this project report, I will discuss a Multiple Linear Programming Query (MLPQ) system and the theoretical background of this system.The MPLQ system is developed to solve some realistic problems involving both linear programming (UP) techniques and linear constraint databases (LCDBs) theory. The MLPQ system is aimed at providing a mechanism of bridging these two important areas. system basically consists of three parts which are a linear constraint database, an LP solver, and an interface between the LCDB and the LP solver. The LCDB of the MLPQ system contains multiple linear programming problems. The LP solver used in the MPLQ is an implementation Of the SIMPLEX method. An important feature of the MLPQ system is that it can handle the SQL aggregate Operators, such as minimum Min, maximum Max, summation Sum, and average Avg. The MLPQ system provides an efficient way of evaluation of aggregate operators for linear constraint databases.