MultiChoice Walkthrough Dr Gordon Russell Copyright Napier University
- Slides: 10
Multi-Choice Walkthrough Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 1
Q 1 n A publishing company produces academic books on various subjects. Books are written by authors who specialise in one or more particular subject. The company employs a number of editors who do not have particular specialisations but who take sole responsibilty for editing one or more publications. A publication covers a single subject area but may be written by one or more author - the contribution of each author is recorded as a percentage for the purposes of calculating royalties. Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 2
Q 1 Continued n The following ER diagram is intended to represent the above specification: Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 3
Q 1 Options Indicate the relation which has an incorrect cardinality shown: A. specialises in B. makes C. is about D. to E. None of the above Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 4
Q 2 The specification is to be changed so that an author can develop a publication covering more than one subject area and that the schema must be able to store the percentage of the compents concerned with each of the subjects. Select an appropriate change to the ER diagram: A. B. C. D. E. publication-subject becomes many to many author-publication becomes many to many more than one of the above none of the above Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 5
Q 3 Consider the relational schema R(A, B, C, D, E) with non-key functional dependencies C, D - E and B - C. Select the strongest statement that can be made about the schema R A. B. C. D. E. R is in first normal form R is in second normal form R is in third normal form R is in BCNF normal form None of the above Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 6
Q 4 Locking was introduced into databases so that A. B. C. D. E. Keys can be provided to maintain security. Reading and writing is possible. All simultaneous transactions are prevented. Passwords can be provided to maintain security Consistency can be enforced. Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 7
Q 5 When accessing a disk block, the seek time A. B. C. D. is insignificant in comparison to transfer times is about the same as transfer times greatly exceeds transfer times is the time taken to search for data in a sorted list of database rows E. is measured in nanoseconds Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 8
Q 6 Hash-table insertions A. avoid hash-collisions by manipulating the foreign keys B. might use hash-chains to allow hash-collisions C. use balanced binary trees to allow hash-collisions D. use primary keys to avoid hash-collisions E. become unusable if there any hash-collisions Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 9
Q 7 When a transaction aborts A. all users must be notified B. all changes it has made are immediately available to other transactions C. the modifications of all transactions currently running are also aborted D. it can abort transactions which have already committed E. it releases all of its locks Dr Gordon Russell, Copyright @ Napier University M/C Walkthrough - V 2. 0 10
