Suppose ORACLE relation R(A, B) currently has tuples {(1, 2), (1, 3), (3, 4)} and relation S(B, C) currently has {(2, 5), (4, 6), (7, 8)}. Consider the following two SQL queries SQ1 and SQ2 :
SQ1 : Select * from R Full Join S On R.B=S.B;
SQL2 : Select * from R Inner Join S On R.B=S.B;
The numbers of tuples in the result of the SQL query SQ1 and the SQL query SQL2 are given by :
| A. | 2 and 6 respectively |
| B. | 6 and 2 respectively |
| C. | 2 and 4 respectively |
| D. | 4 and 2 respectively |
|
Option: D Explanation : Click on Discuss to view users comments. |
Consider the following three SQL queries (Assume the data in the people table) :
(a) Select Name from people where Age>21;
(b) Select Name from people where Height>180;
(c) Select Name from people where (Age>21) or (Height>180);
If the SQL queries (a) and (b) above, return 10 rows and 7 rows in the result set respectively, then what is one possible number of rows returned by the SQL query (c) ?
| A. | 3 |
| B. | 7 |
| C. | 10 |
| D. | 21 |
|
Option: C Explanation : Click on Discuss to view users comments. |
The distributed system is a collection of (P) and communication is achieved in distributed system by (Q) , where (P) and (Q) are :
| A. |
Loosely coupled hardware on tightly coupled software and disk sharing, respectively.
|
| B. |
Tightly coupled hardware on loosely coupled software and shared memory, respectively.
|
| C. |
Tightly coupled software on loosely coupled hardware and message passing,respectively.
|
| D. | Loosely coupled software on tightly coupled hardware and file sharing, respectively. |
|
Option: C Explanation : Click on Discuss to view users comments. |
| A. | x1 -x2 -0.5=0 |
| B. | -x1 +x2 -0.5=0 |
| C. | 0.5(x1 +x2 )-1.5=0 |
| D. | x1 +x2 -0.5=0 |
|
Option: D Explanation : Click on Discuss to view users comments. |
