Exam442_09 - StudentId_ EXAMINATIONS 2009 MID-YEAR COMP 442...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
StudentId______________ EXAMINATIONS 2009 MID-YEAR COMP 442 ISSUES IN DATABASE AND INFORMATION SYSTEMS Time Allowed: 3 Hours (180 minutes) Instructions: Attempt all questions. There are 180 possible marks on the exam. Make sure your answers are clear and to the point. Non-programmable calculators without full alphabetic keys are permitted. Non-electronic foreign language dictionaries are permitted. Refer to the Appendix. No other reference material is allowed. Answer in the appropriate heavily outlined boxes or follow the instructions given in the questions. Question Topic Marks 1 The Constellation Database [15 marks] 2 Query Rewriting [25 marks] 3 OLAP and Data Warehouse Architectures [10 marks] 4 XML Document, DTD, and XML Schema [30 marks] 5 XQuery [25 marks] 6 A Formal Approach to XML and XML FD’s [30 marks] 7 XML Normal Form [45 marks] Note: Marks are shown for each question as a whole and also for their parts.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
StudentId______________ COMP442 2 continued Question 1. The Constellation Database [15 marks] Consider the multiple aggregates constellation schema given in Figure 1.1. Suppose there are: 10000 products sold in 10 districts, each containing 10 cities with 10 supermarkets, during 10 years with 350 days per year supermarkets open District DistrictId Distt_Desc City CityId City_Desc DistrictId Shop ShopId Shop_Desc CityId Sales_District TimeId ProductId DistrictId Amount Sales_City TimeId ProductId CityId Amount Sales_Shop TimeId ProductId ShopId Amount Time TimeId Time_Desc Product ProductId Prod_Desc Figure 1.1. a) [4 marks] Calculate the maximum number of tuples that the Sales_Shop fact table may contain. ANSWER
Background image of page 2
StudentId________________ COMP442 continued 3 b) [4 marks] Calculate the maximum number of tuples that the Sales_City fact table may contain. ANSWER c) [4 marks] Calculate the maximum number of tuples that the Sales_District fact table may contain. ANSWER d) [3 marks] The Sales_District fact table is a materialized view of the Sales_Shop fact table. Suppose a query Q issued against the Sales_Shop table can be answered using the Sales_District table. If the answer time is proportional to the number of tuples in a table, how many times faster will it be to answer the query Q using the Sales_District , instead of using the Sales_Shop fact table. ANSWER
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
StudentId________________ COMP442 continued 4 Question 2 Query Rewriting [25 marks] Consider the following star schema: { Sales ({ TimeId , ProdId , ShopId , Amnt }, { TimeId + ProdId + ShopId }), Time ({ TimeId , Day , Week , MonthId , Month_Name , Year }, { TimeId }), Product ({ ProdId , Prod_Name , TypeId , Type_Name, Industry }, { ProdId }), Location ({ ShopId , CityId , City_Name , Country }, { ShopId })} Suppose attribute hierarchies are defined using the following sets of functional dependencies: Product hierarchy : ProdId Prod_Name, ProdId TypeId , TypeId Type_Name , TypeId Industry . Time hierarchy
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 23

Exam442_09 - StudentId_ EXAMINATIONS 2009 MID-YEAR COMP 442...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online