DOEACC Society 2006 DOEACC B Level - B2.2 Introduction to Database Management Systems ( ) - Question Paper

level(5).
A) Only physical
B) Conceptual and view
C) Physical and conceptual
D) None of the above
1.8 Which of the subsequent are minimal keys for a relation R with F = {AB?C, C?A}:
A) AB, AC
B) AB, BC
C) BC, AC
D) ABC, AB
1.9 B+ Trees are preferred to binary trees since
A) Disk capacities are higher than memory capacities
B) Memory access is faster than disk access
C) Disk are more reliable than memory
D) Disk data transfer rates are much less than memory transfer rates.
1.10 Under which condition, the value R ÿ S / S equal to R (here ÿ stands natural join and /
denotes division).
A) When R and S are having at lowest 1 attribute common
B) The degree of S is less than the degree of R.
C) The degree of R is less than the degree of S.
D) When R and S are having no attribute in common.
B2.2-R3 Page two of five July, 2006
2. every statement beneath is either actual or FALSE. select the most improper one
and ENTER in the “tear-off” sheet attached to the ques. paper, subsequent
instructions therein. (1 x 10)
2.1 SERIALIZABLE is 1 the transaction isolation level in Structured Query Language.
2.2 Two-phase locking protocol is an optimistic based protocol.
2.3 The process of check pointing decreases the amount of work done by DBMS during the
restarting process.
2.4 Usage of Table alias is essential in performing a join operation of table R with itself.
2.5 Tuple relational calculus is declarative and procedural oriented language.
2.6 Selection, projection, union, difference, intersection and Cartesian product operations
formulate a complete set of relational algebra.
2.7 Any arithmetic comparison involving null is always an null.
2.8 Domain relational calculus restricted to safe domain expressions is equivalent in
expressive power to the basic relational algebra.
2.9 Logging and recovery manager is responsible for the durability of transactions.
2.10 Minimal cover for a provided set of Functional dependencies F is unique.
3. Match words and phrases in column X with the nearest related meaning/
word(s)/phrase(s) in column Y. Enter your selection in the “tear-off” ans sheet
attached to the ques. paper, subsequent instructions therein. (1 x 10)
X Y
3.1 Physical Model A. Used to discard the false groups from a
table
3.2 Secondary index B. B-tree
3.3 Non-procedural query C. Relational algebra

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