Q. The best normal form of relation scheme R(A. B, C, D) along with the set of functional dependencies F = {AB → C, AB → D, C → A, D → B} is

View solution

Q. Identify the minimal key for relational scheme R(A, B, C, D, E) with functional dependencies F = {A → B, B → C, AC → D}

View solution

Q. Division operation is ideally suited to handle queries of the type :

View solution

Q. What kind of mechanism is to be taken into account for converting a weak entity set into strong entity set in entity-relationship diagram?

View solution

Q. Which of the following is true?

I.  Implementation of self-join is possible in SQL with table alias.

II. Outer-join operation is basic operation in relational algebra.

III. Natural join and outer join operations are equivalent.

View solution

Q. Which of the following is correct?

I. Two phase locking is an optimistic protocol.
II. Two phase locking is pessimistic protocol
III. Time stamping is an optimistic protocol.
IV. Time stamping is pessimistic protocol.

View solution

Q. ________________rules used to limit the volume of log information that has to be handled and processed in the event of system failure involving the loss of volatile information.

View solution

Q. Let R = ABCDE is a relational scheme with functional dependency set F = {A -> B, B ->C,AC -> D}. The attribute closures of A and E are

View solution

Q. Consider the following statements:

I. Re-construction operation used in mixed fragmentation satisfies commutative rule.
II. Re-construction operation used in vertical fragmentation satisfies commutative rule
Which of the following is correct?

View solution

Q. Which of the following is false?

View solution

Q. An Assertion is a predicate expressing a condition we wish database to always satisfy. The correct syntax for Assertion is :

View solution

Q. Which of the following concurrency protocol ensures both conflict serializability and freedom from deadlock ?

(a) 2-phase Locking
(b) Time stamp - ordering

View solution

Q. Drop Table cannot be used to drop a Table referenced by ________________ constraint.

(a) Primary key (b) Sub key (c) Super key (d) Foreign key

View solution

Q. Database applications were built directly on top of file system to overcome the following drawbacks of using file systems.
(a) Data redundancy and inconsistency
(b) Difficulty in accessing Data
(c) Data isolation
(d) Integrity problems

View solution

Q. For a weak entity set to be meaningful, it must be associated with another entity set in combination with some of their attribute values, is called as :

View solution

Q. Which of the following statements is FALSE about weak entity set ?

View solution

Q. Let E1 and E2 be two entities in E-R diagram with simple single valued attributes. R1 and R2 are two relationships between E1 and E2 where R1 is one - many and R2 is many - many. R1 and R2 do not have any attribute of their own. How many minimum number of tables are required to represent this situation in the Relational Model?

View solution

Q. The STUDENT information in a university stored in the relation STUDENT (Name, SEX, Marks, DEPT_Name)
Consider the following SQL Query SELECT DEPT_Name from STUDENT where SEX = 'M' group by DEPT_Name having avg (Marks)>SELECT avg (Marks) from STUDENT. It returns the Name of the Department for which:

View solution

Q. Select the 'False' statement from the following statements about Normal Forms :

View solution

Q. The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because:

View solution