ECS 289F Topics in Scientific Data Management Spring 2006
Dr. Bertram LudĀØascher April 18
Assignment 1
Due: Tuesday, April 25th (in class, after class)
Problem 1
Consider the rock classification hierarchies (Slide 30, Handout 1):1A set of rock-names is hierarchically
classified according to different properties (fabric,chemical-composition,texture).
a) For each of the different hierarchies, explain what the parent-child relation between two nodes
means. What does a node stand for?
b) Give another example of an (ideally scientific) application domain, in which a set of terms (or
names) gives rise to two (or more) different hierarchies. Choose an example, such that a significant
amount of terms occur in more than one hierarchy.
c) Consider a set of terms T={t1, . . . , tn}and two hierarchies isaA/2,isaB/2, i.e., terms Tcan
be classified hierarchically w.r.t. two different organizational aspects Aand B. Now consider a
database instance Iover the schema S={isaA/2,isaB/2}, i.e., a finite set of facts of the form
isaA(tchild, tparent ) and isaB(tchild, tparent ). Discuss how you might āmine new knowledgeā about T
and/or Aand B, using I. Use examples from (a) or (b) to illustrate.
Problem 2
Consider the following definitions of concepts:
ā¢AHappyFather is a Man such that all of his children are Rich or Happy.
ā¢AHappyMother is a Woman with at least one child that is Happy.
a) Define HappyFather and HappyMother using description logic (DL) syntax. Use a binary relation
hasChild/2 to model the parent-child relationship.
b) Same as in (a) but use first-order (FO) logic syntax. Hint: Use the translation rules from DL to
FO from class.
Now consider the database schema S={Person(SSN, N ame, Gender),
hasChild(SS N P arent, S SN C hild),
Rich(SSN),Happy(SSN)}
c) Define Man,Woman,HappyFather, and HappyMother as Datalog views over S.
Hint: to express a universal statement (such as āparents having only girlsā) you might want to
use double negation (e.g. ānot among the parents having no girlsā).
d) Same as in (c), but use SQL views.
e) Give a database instance Iof Shaving a happy father and mother, and an unhappy father and
unhappy mother. Try to make Ias small as possible.
1The original article will also be available via the class page.
