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 A must have the same value for B
No two tuples in R can have the same value for attribute A
No two tuples in R can have the same value for attribute B
Any two tuples in R that have the same value for B must have the same value for A
Which of the following commands can be used to modify a tuple to other value?
ALTER TABLE ADD
UPDATE
SELECT …FOR UPDATE
INSERT INTO
A relation schema R is in 3rd normal form if
R contains only 3 keys
R satisfies 2nd normal form and no nonprime attribute of R is transitively dependent on the primary key
Each nonprime attribute in R is fully dependent on every key
All attributes in R have atomic domains
The ........ is used for creating and destroying table, indexes and other forms of structures.
transaction control language
data manipulation language
data control language
data definition 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
Which of the following is not a binary operator in relational algebra?
Join
Assignment
Semi-Join
Project
…………..defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
Instance
Program
Schema
Super Key
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 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;
SELECT * FROM employees WHERE department_id = 90 , salary >= 8000;
SELECT * FROM employees WHERE department_id = 90 AND salary > 8000;
SELECT * FROM employees WHERE department_id = 90 AND salary >= 8000.00;
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