© M.E. Fayad SJSU -- CmpE Database Design Dr. M.E. Fayad, Professor Computer Engineering Department, Room #283I College of Engineering San José State University One Washington Square San José, CA

L8-2-S2 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad 2 Lesson 08-II: The MLPQ System

L8-2-S3 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Lesson Objectives 3 Understand the MLPQ System Learn about: î Database System Architecture î MLPQ Input Files î MLPQ Graphical User Interface î Recursive Queries

L8-2-S4 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad MLPQ MLPQ is short for Management of liner programming queries. MLPQ is a constraint database system for rational linear constraint databases. It allows: –Datalog Queries –Minimum and maximum aggregation operations over linear objective functions –And other operators 4

L8-2-S5 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Two Main Application Areas Operations research when the available data in a database needs to be reformulated by some database query before we can solve a problem by linear programming. Dealing with spatial and spatiotemporal data. The MLPQ allows the ability to go beyond two or three dimensions of mutually constrained data. 5

L8-2-S6 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad System consists of six main modules: –Representation –Query Evaluation –Visualization –Approximation –Update –Export Conversion Refer to Chapter 18 for a diagram and more details The MLPQ Database System Architecture 6

L8-2-S7 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad MLPQ Input Files Each Input File has this structure: begin %moduleName%  1  2.  n end %moduleName% Where  n is a Datalog Rule or rational linear constraint tuple. 7

L8-2-S8 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Differences between Datalog and MLPQ Input File Each Linear constraint has the form: a 1 x 1 + a 2 x 2 + … + a n x n  b Where each a i is a constant and each x i is a variable, and  i is a relation operator of the from =,, =. The optional aggregate operator has the from OP(f) where OP is one of the aggregate optators: max, min, MAX, MIN, sum_max, sum_min, and f is a liner function of the variables in the rule. 8

L8-2-S9 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Differences ( continued ) For the negation the symbol ! Is used instead of not. The Module Name controls what type of query evaluation methods will be used. It should be one of these strings: –MLPQ – to evaluate only non-recursive Datalog Queries. –RECURSIVE – to evaluation recursive Datalog Queries –GIS – to evaluate both Datalog and iconic queries 9

L8-2-S10 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Example Database file – regions.txt begin%Test% country(id,x,y,t):- id = 1, x >= 0, x =5, y =1800, t <=1950. country(id,x,y,t):- id = 1, x >= 0, x =5, y =1950, t <= country(id,x,y,t):- id = 2, x >= 4, x =5, y = 1800, t <=1950. country(id,x,y,t):- id = 2, x >= 8, x =5, y = 1950, t <= country(id,x,y,t):- id = 3, x >= 0, x =0, y = 1800, t <= location(c,x,y):- x = 3, y = 2, c = 101. location(c,x,y):- x = 7, y = 3, c = 102. location(c,x,y):- x = 5, y = 6, c = 103. location(c,x,y):- x = 7, y = 10, c = 104. location(c,x,y):- x = 10, y = 8, c = 105. location(c,x,y):- x = 1, y = 7, c = 106. location(c,x,y):- x = -8, y = 6, c = 107. growth(t,c,p):- c = 101, p = 10000, t >=1800, t <= growth(t,c,p):- c = 102, p = 20000, t >=1800, t <= growth(t,c,p):- c = 103, p = 10000, t >=1800, t <= growth(t,c,p):- c = 104, p = 30000, t >=1800, t <= growth(t,c,p):- c = 105, p = 40000, t >=1800, t <= growth(t,c,p):- c = 106, p = 35000, t >=1800, t <= end%Test% 10

L8-2-S11 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad The MLPQ Graphical User Interface 11

L8-2-S12 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad SQL Query Find all cities that in 1900 belonged to the USA and had a population of over Click [Qs], click SQL - Basic button In Create View field enter: “cityUSA1900” In Select field enter: “growth.c, location.x, location.y” In From field enter: “growth, location, country” In Where field enter: “growth.c = location.c, location.x = country.x, location.y = country.y, growth.t = 1900, growth.p > 10000, country.id = 1, country.t = 1900” 12

L8-2-S13 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Results 13

L8-2-S14 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Many Operators 14

L8-2-S15 MLPQ © M.E. Fayad SJSU -- CmpE-- M.E. Fayad Recursive Queries Recursive Datalog queries are entered the same way as non-recursive queries except that the module name is changed to RECURSIVE. This activates some special evaluation routines that are applicable for recursive queries only.