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Noorul Islam University 2008 M.Sc Software Engineering XCS 235 – DATABASE MANAGEMENT SYSTEMS - Question Paper

Monday, 04 February 2013 01:35Web

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a) Open addressing
b) Chaining
c) Multiple hashing
48. What is external hashing?
Hashing for disk files is called external hashing.
49. What is local depth in extendible hashing?
A local depth stored with every bucket specifies the number of bits on which the
bucket contents are based.
50. What is file load factor?
The file load factor lion can be described as lion=r/(bfr*N)
51. describe relation schema.
A relation schema red denoted by R(A1,A2,….An) is made up of a relation name
Red and a list of attributes A1,A2…..An.
52. describe degree of relation.
The degree of relation is the number of attributes n of its relation schema.
53. describe relation state.
A relation red of the relation schema R(A1,A2…..An) is a set of tuples
r={t1,t2,…..tn).
54. State the characteristics of relations.
a) ordering of tuples in a relation
b) ordering of values within a tuple
c) values in the tuples
d) interpretation of a relation.
55. describe super key.
A super key specifies a uniqueness constraint that no distinct tuples in a state r of
Red can have the identical value for superkey.
56. describe a candidate key.
A relation schema may have more than 1 key is called a candidate key.
57. describe relational database schema
A relational database schema S is a set of relation schemas S={R1,R2…Rn} and
a set of integrity constraints.
58. describe relational database state.
A relational database state of S is a set of relation states Db={r1,r2….rm) such
that every ri is a state of Ri and such that the ri relation state satisfy the integrity
constraints.
59. elaborate the basic update operations on relations?
a) insert
b) delete
c) replace
60. describe mapping or choose from where clause.
choose FROM
WHERE
61. describe functional dependency.
A functional dependency is a constraint ranging from 2 sets of attributes from the
database.
62. State the inference rules of functional dependency.
a) reflexive rule
b) augmentation rule
c) transitive rule
d) decomposition rule
e) union or additive rule
f) pseudo transitive rule.
63. What is normalization?
Normalization of data is a process of analyzing the provided relation schemas based