For the following questions answer them individually
If $$D_1, D_2, ....., D_n$$ are domains in a relational model, then the relation is a table, which is a subset of
Consider the following relational query on the above database:
SELECT S.sname
FROM Suppliers S
a WHERE S.sid NOT IN (SELECT C.sid
FROM Catalog C
WHERE C.pid NOT IN (SELECT P.pid
FROM Parts P
WHERE P.color < > ‘blue’))
Assume that relations corresponding to the above schema are not empty. Which of the following is the correct interpretation of the above query?
Consider the following schema:
Emp (Empcode, Name, Sex, Salary, Deptt)
A simple SQL query is executedasfollows:
SELECT Deptt FROM Emp
WHEREsex = ‘M’
GROUP by Dept
Having avg (Salary) > { select avg (Salary) from Emp}
The output will be
Given the following expression grammar:
$$E \rightarrow E * F \mid F + E \mid F$$
$$F \rightarrow F - F \mid id$$
Which of the following is true?
Which grammar rules violate the requirement of the operator grammar? A, B, C are
variables and a, b, c are terminals
(i) $$A \rightarrow BC$$
(ii) $$A \rightarrow CcBb$$
(iii) $$A \rightarrow BaC$$
(iv) $$A \rightarrow ε$$
Semaphoresare used to solve the problem of
(i) race condition
(ii) process synchronization
(iii) mutual exclusion
(iv) none of the above