Faculty of Environment & Technology

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1 Faculty of Environment & Technology Academic Year: 2012/13 Module Leader: Module Code: Title of Module: Prakash Chatterjee UFCE8K-15-M Data Management Examination Date: TBA Examination Start time: TBA Duration of Examination: 3 Hours Instructions to Candidates: Candidates must answer ALL questions from Section A and ANY THREE questions from Section B Materials supplied to the candidate will be: Number of Examination Booklets per Examination 1 Number of sheets of Graph Paper size G3 (Normal) 0 Number of Pre-printed OMR (Multiple Choice Answer Sheet) 0 Additional Instructions to Invigilators: University approved calculators may be used Candidates permitted to keep Examination Question Paper Material supplied by student allowed (must be collected with answer booklet) please specify: Yes Yes No Additional Specialised Material : NONE Treasury tags will be supplied as standard Page 1 of 8

2 Answer ALL questions in this section (Questions 1 and 2). Question 1 Consider the following MySQL DDL statements; CREATE TABLE book ( b_id varchar(8) NOT auto_increment, b_isbn varchar(16) NOT NULL default '', b_title varchar(64) NOT NULL default '', b_subject varchar(32) NOT NULL default '', b_price decimal(3,2) NOT NULL default '0.00', b_pub_date date NOT NULL default ' ', p_id int(6) NOT NULL default '0', PRIMARY KEY (b_id), UNIQUE KEY b_isbn (b_isbn), FOREIGN KEY (p_id) REFERENCES publisher(p_id) ); CREATE TABLE publisher ( p_id int(6) NOT NULL auto_increment, p_name varchar(36) NOT NULL default '', p_address1 varchar(24) NOT NULL default '', p_address2 varchar(24) NOT NULL default '', p_address3 varchar(24) default NULL, p_city varchar(32) NOT NULL default '', p_country varchar(24) NOT NULL default '', p_url varchar(64) NOT NULL default '', p_contact varchar(64) NOT NULL default '', p_phone varchar(16) NOT NULL default '', PRIMARY KEY (p_id) ); CREATE TABLE author ( a_id int(6) NOT NULL auto_increment, a_lname varchar(24) NOT NULL default '', a_fname varchar(24) NOT NULL default '', a_ varchar(32) NOT NULL default '', PRIMARY KEY (a_id) ); CREATE TABLE book_author ( b_id int(8) NOT NULL default '0', a_id varchar(6) NOT NULL default '0', PRIMARY KEY (b_id,a_id), FOREIGN KEY (b_id) REFERENCES book(b_id), FOREIGN KEY (a_id) REFERENCES author(a_id) ) Page 2 of 8

3 a) Draw an ER diagram, showing the entities, attributes and relationships with the appropriate multiplicities. Underline all primary keys and dash underline all foreign keys. Note that you need to show how the multiplicities are resolved using the link table. 13 marks b) The following table shows four records taken from the book table b_id b_isbn b_title b_subject b_price b_pub_date p_id MySQL & msql Database, Computing, SQL XQuery: The XML Computing, Query Language Programming, Mark Up Languages, XML, XQuery Isaac Newton Science, Physics, History of Science, Biography Introducing Postmodernism Cultural Studies, Philosophy, Postmodernism, Literary Theory i) Define what is meant by the term Candidate Key and using the DDL statements and the data given above - identify the two candidate keys for this table. 2 marks ii) The data given for the book table shows that it breaks the rule of the First Normal Form (1NF). Explain this rule and identify how this table breaks this rule. iii) Normalise the above table and illustrate this by a drawing a logical ER model showing the book entity and any others entities you create and how they relate. 6 marks Page 3 of 8

4 Question 2 a) Using the DDL statements from Question 1, define the SQL statements for each of the following queries. i) List all the books showing the book title, isbn, cost and published_date ordered by descending published_date. ii) List the book ID, title and subject of all books where the subject includes the word Computing. iii) List the isbn and the name of the publisher for the book with the title XQuery: The XML Query Language. iv) List all book title and author surname of any books published before 1 st January v) List the title, publisher name and all authors first name concatenated with last name for any book in the Computing subject area. b) List and explain the SQL CRUD operations for the factbase and the schema. 5 marks Page 4 of 8

5 SECTION B Answer any TWO (2) questions in this section. Question 3 Jar Jar Binks wants to open his own e-store and sell items sourced throughout the Empire. He has attended a data modelling course and as a first step managed to identify the following "requirements". o The store will sell many product types organized by categories. o Each product will belong to at least one and possibly more categories. o Some categories are "top-level" - they can have sub-categories but cannot be subcategories themselves. o Each product item will have a name, a description, a price and the quantity held in stock. o The store will (hopefully) have many customers. o Customers will place one or more orders. We will need to hold customers name, address and login details. o Each order will consist of one or more product items. o We need to hold details about the customer, date/time & total for each order. a) Identify the top-level entities. 6 marks b) Identify the entities, attributes and relationships and draw a conceptual (top-level) ER model. 9 marks c) Draw a logical (relational) E-R model, showing all primary keys marked as "(PK)", foreign keys as "(FK)" and all many-to-many relationships resolved. Relationships should be named and show their cardinality. Attributes should be named but need not show their data type. 10 marks Page 5 of 8

6 Question 4 Consider the following pseudo-code: BEGIN TRANSACTION; UPDATE ACCOUNT 123 ( BALANCE := BALANCE ); IF any error occurred THEN GO TO UNDO; END IF; UPDATE ACCOUNT 123 ( BALANCE := BALANCE - 70 ); IF any error occurred THEN GO TO UNDO; END IF; COMMIT ; GO TO FINISH ; UNDO ROLLBACK ; FINISH RETURN ; a) Explain the pseudo-code and give the relative balance of the account given after the transaction completes. 6 marks b) Explain the COMMIT and ROLLBACK operations. 9 marks c) Explain the ACID properties that are usually associated with a transaction process, 10 marks Page 6 of 8

7 QUESTION 5 a) With the aid of diagram, identify and describe the logical layers and the relationships of a 3-tier application architecture. 8 marks b) What are the technical advantages gained from separating the layers in this manner? 10 marks c) Identify the typical tools and technologies used in each layer of a web-based 3 tier application framework. 7 marks Page 7 of 8

8 Question 6 a) Identify and discuss the major differences between a xml approach and a relational approach to structuring and validating data. 13 marks b) Identify and discuss the three different means of storing and using collections of xml documents using current database technology. 12 marks Page 8 of 8