The deadlock in a set of transaction can be determined by

When transaction Ti requests a data item currently held by Tj , Ti is allowed to wait only if it has a timestamp larger than that of Tj (that is, Ti is younger than Tj ). Otherwise, Tj is rolled back (Tj is wounded by Ti). This is

The deadlock state can be changed back to stable state by using _____________ statement.

If transaction Ti gets an explicit lock on the file Fc in exclusive mode, then it has an ­­­­­­__________ on all the records belonging to that file.

Which of the following protocols ensures conflict serialzability and safety from deadlocks?

A lock that allows concurrent transactions to access different rows of the same table is known as a

In SQL, __________ is an Aggregate function.

Which of the following is/are true with reference to ‘view’ in DBMS?

(a) A ‘view’ is a special stored procedure executed when certain event occurs.

(b) A ‘view’ is a virtual table, which occurs after executing a pre-compiled query.

code:

Consider the following relational schema:

Employee Detail (EmpId, Full Name, Manager ID, Date Of Joining)

Employee Salary (Emp ID, Project, Salary)

Consider the following relational query on the above database:

SELECT Salary

FROM Employee Salary Emp1

WHERE 2 = (

SELECT COUNT( DISTINCT ( Emp2.Salary ) )

FROM Employee Salary Emp2

WHERE Emp2.Salary >= Emp1.Salary

)

Assume that relations corresponding to the above schema are not empty. Which one of the following is the correct interpretation of the above query?

Consider the following statements regarding relational database model:

(a) NULL values can be used to opt a tuple out of enforcement of a foreign key.

(b) Suppose that table T has only one candidate key. If Q is in 3NF, then it is also in BCNF.

(c) The difference between the project operator (Π) in relational algebra and the SELECT keyword in SQL is that if the resulting table/set has more than one occurrences of the same tuple, then Π will return only one of them, while SQL SELECT will return all.

One can determine that:

Which of the following is the right syntax for assertion?

Given relations r(w, x) and s(y, z), the result of

SELECT DISTINCT w, x

FROM r, s

is guaranteed to be same as r, provided

In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as:

The ______ clause allows us to select only those rows in the result relation of the ____ clause that satisfy a specified predicate.

Select name, course_id

from instructor, teaches

where instructor_ID= teaches_ID;

This Query can be replaced by which one of the following?

In a relational database model, NULL values can be used for all but which one of the following?

Which normal form is considered adequate for normal relational database design?

Consider the following query :

SELECT E.eno, COUNT(*)

FROM Employees E

GROUP BY E.eno

If an index on eno is available, the query can be answered by scanning only the index if__________________

Entity is a _________.

A top-to-bottom relationship among the items in a database is established by a ________.