The functional dependency A Þ B for relation schema R(A,B,C,D) implies that
Any two tuples in R that have the same value for B must have the same value for A
Any two tuples in R that have the same value for A must have the same value for B
No two tuples in R can have the same value for attribute B
No two tuples in R can have the same value for attribute A
Which of the following lines of the SELECT statement contains an error?
line 1
line 2
line 3
There are no errors- statement returns intended results
Which of the following is not a binary operator in relational algebra?
Semi-Join
Project
Assignment
Join
…………..defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
Program
Super Key
Instance
Schema
A relation schema R is in 3rd normal form if
R contains only 3 keys
Each nonprime attribute in R is fully dependent on every key
R satisfies 2nd normal form and no nonprime attribute of R is transitively dependent on the primary key
All attributes in R have atomic domains
Which of the following will display all the employees in department 90 and having a salary of at least $8000.00?
SELECT * FROM employees WHERE department_id = 90 AND salary >= 8000.00;
SELECT * FROM employees WHERE department_id = 90 AND salary >= 8000;
SELECT * FROM employees WHERE department_id = 90 AND salary > 8000;
SELECT * FROM employees WHERE department_id = 90 , salary >= 8000;
The ........ is used for creating and destroying table, indexes and other forms of structures.
data manipulation language
data definition language
data control language
transaction control language
For like predicate which of the following is true
i) % matches zero of more characters.
ii) _ matches exactly one character.
i-only
ii-only
Both of them
None of them
Given the set of functional dependencies, (AB Þ CDE and A Þ E) , for relation scheme R = (A,B,C,D,E) we can infer the following:
A is a key for R
BE is a key for R
AB is a key for R
None of the above
Which of the following commands can be used to modify a tuple to other value?
SELECT …FOR UPDATE
ALTER TABLE ADD
INSERT INTO
UPDATE