MIDTERM
EXAMINATION
Spring
2010
CS403-
Database Management Systems (Session - 6)
Q- Which of the following constraints
enforces entity integrity? PRIMARY KEY
FOREIGN KEY
CHECK
NOT NULL
Q- Which of the following statements is correct? PK can have NULL
PK in a relation is a key in some other relation
PK can be composite
PK must be selected from the list of secondary keys
A binary relationship
A ternary relationship
A recursive relationship
An identifying relationship
Q- A database system allows the following EXCEPT
management and control of data towards an efficient working of an organisation.
more critical functions in organisations to be computerised and the need
to keep a large volume of data available in an up to the minute current state increased.
any user to access all its data.
integration of data across multiple applications into a single application.
Q- Which of the following enforces a relation into 1st normal form?
► The domain of attribute must include only atomic values.
► Every non-key attribute
is fully functionally dependent on primary key
► non-key attribute
is non-transitively dependent on primary key.
► Every non-key attribute
is partially dependent on super key
Q- Consider the following set of functional dependencies (FDs) on the following
relational schema.
Emp_No -> {Ename, Bdate, Address, Dept_No}
Dept_No -> {Dname, Mgr_No}
The additional FD which can be inferred from the above set of FDs is
Emp_No -> {Dname, Mgr_No} Emp_Name -> Dept_No . Emp_Name -> Dept_Name
. Emp_Name, Dept_No -> Mgr_No .
Q- Select the correct statement about the ANSI/SPARC architecture.
► The conceptual level
is a level of indication between the internal level and the external level.
► The internal level
in a database system will definitely be relational. Tuka uncle lagao…
► Any given database
has many conceptual schemas and one physical schema, but it has only one external
schemas.
► The external level
is not concerned with individual user perceptions, while the conceptual level
is concerned with a community user perception.
Q- Which of the following is a feature of PRIMARY KEY constraint unique
identifier for a row within a database table.
allow any actions that would destroy links between tables limit the values
that can be placed in a column.
enforces that the column will only accept null values. Q- Structural constraints
of a relationship type refer to
► identifying the
owner entity type relevant to a given entity type
the
► whether the existence of an entity depends on it being related to another
entity via
relationship type.
► the role that a
participating entity from the entity type plays in each relationship instance.
► the constraints
applicable in granting access to tables, columns and views in a database
schema.
Q- Which of the following is true about relational schema?
► The sequence of
columns is significant
► The sequence of
rows is significant.
► Contains only derived attributes.
► Values are atomic.
Q- A unary ternary binary
weak
relationship exists when an association is maintained within a single entity.
Q- Which of the following is a correct way to implement one-to-many relationship
while designing tables?
► by splitting the
data into two tables with primary key and foreign key relationships.
► using a junction
table with the keys from both the tables forming the composite primary key of the
junction table.
► by splitting each
table into three
► as a single table
and rarely as two tables with primary and foreign key relationships.
Q- Identify the correct statement.
► Entity integrity
constraints specify that primary key values can be composite.
► Entity integrity
constraints are specified on individual relations.
► Entity integrity
constraints are specified between weak entities.
► When entity integrity rules are enforced, a tuple in one relation that
refers to another relation
must refer to an existing tuple.
Q- A software package designed to store and manage databases
Database
DBMS
Data model
Data
Q- Who is responsible for authorizing access to the database, for coordinating
and monitoring its use?
Select correct option:
Database Designer
Database Administrator
End User
Application Programmer
Q- Consider the following relation R and its sample data. (Consider that
these are the only tuples for the given relation)
Q- Which of the following statements is NOT correct?
► The functional dependency
(EmpNo, DeptNo) -> ProjNo holds over R.
► The functional dependency
EmpNo -> DeptNo holds over R.
► The functional dependency
ProjNo -> DeptNo holds over R.
► The functional dependency
(EmpNo, ProjNo) -> DeptNo holds over R.
Q- Which feature of database provides conversion from inconsistent state
of DB to a consistent state ensuring minimum data loss?
Select correct option:
User accessible catalog
Data processing
Recovery service
Authorization service
Q- Consider the given relations Student and Instructor as given below. Please
note that
Fname and Lname also denote the First Name and Last Name respectively.
Which of the following statements is correct with respect to the two relations
given above?
The two relations are not union-compatible since their attribute names differ.
The set operations such as CARTESIAN PRODUCT and DIVISION can be applied
on
these
two relations.
To find out those students who work as instructors, it is necessary to perform
the operation
Student ∩ Instructor.
To find out the students who are not instructors, it is necessary to perform
the operation
Student ÷ Instructor.
Q- A candidate key that does not have a null value and is selected to
uniquely identify all other attribute values in any given row is called a .
Select correct option:
superkey candidate key primary key secondary key
Q- What is the significance of normalization? Q- Define Relationship.
Q- What is the basic function of a DML Compiler? Q- Define primary key and
give one example.
Q- What do you know about Insertion anomaly?
Q- Define the first normal form.\
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