Can you pls elaborate on these.

1.regular subquery:

SELECT MAX(SALARY)

FROM EMPLOYEE

WHERE SALARY NOT IN (SELECT MAX(SALARY) FROM EMPLOYEE);

the above query returns thesecond maxsalary in EMPLOYEE table.

2.correlated subquery:

SELECT ID,NAME

FROM EMPLOYEE E

WHERE SALARY > (SELECT AVG(SALARY) FROM EMPLOYEE WHERE DNO=E.DNO);

the above query returns the ID,NAME of an employee whose salary is greater than average salary of their department.