Database Management Systems Mid - I, September - 2014

1.In Relational model, data and relationships are represented as a collection of ________.
  • Tables
  • Records
  • Trees
  • Graphs
Answer: A
2.In the architecture of database system external level is the _____________ level.
  • physical
  • logical
  • conceptual
  • view
Answer: D
3.An entity set that does not have sufficient attributes to form a primary key is a _________ entity set.
  • strong
  • weak
  • primary
  • simple
Answer: B
4.In E-R model ellipses represents _______________.
  • entity sets
  • attributes
  • relationships
  • objects
Answer: B
5.A relational model which allows non-atomic domain is _______________.
  • nested relational data model
  • non-atomic data model
  • hierarchical data model
  • none of these
Answer: A
6.Which of the following is not a characteristic of relational data model?
  • Tables
  • Tree like structures
  • complex logical relationships
  • records
Answer: B
7.___________ key is used to represent relationship between tables.
  • Primary
  • Secondary
  • Foreign
  • Candidate
Answer: C
8._______ produces the relation that has attributes of R1 and R2
  • Cartesian product
  • Difference
  • Intersection
  • Product
Answer: A
9.The SQL statement that is used to change the definition of a table is _____________.
  • Alter
  • Update
  • Select
  • Create
Answer: A
10.Which of the following operation is used for retrieving certain columns of a table?
  • JOIN
  • SELECTION
  • PROJECTION
  • UNION
Answer: C
11.DDL statements are compiled, resulting in a set of tables stored in a special file called a________________.
Answer: Data Dictionary
12.A minimal super key that is used to uniquely identify a tuple in relation is called _______________ key.
Answer: candidate
13.The degree of the relation is also called as __________.
Answer: Arity
14.To indicate a relationship set participates in another relationship set _____________ is used.
Answer: AGGREGATION
15.In relational algebra cross product is also called as _____________.
Answer: Cartesian product
16.The symbolic notation for representing SELECT operation in relational model is _______.
Answer: σ
17.Frequency distributions can be created quickly and easily using __________ clause in SQL.
Answer: GROUP BY
18.A data manipulation command the combines the records from one or more tables is called_______________.
Answer: JOIN
19.The operator that is used for pattern matching in SQL is _________.
Answer: LIKE
20.The SQL statement that is used to delete a particular column in a relation/table is _______.
Answer: ALTER