What is true about triggers I. instead of trigger can be used on tables and views 2. instead of trigger can fire at eah row and statement levels. 3. Compund trigger in 10g allows us to specify multiple timig events on single database objects. 4. we should not use the same object which fired the trigger inside the trigger. this will result in mutating trigger error.

For which constraints are indexes created when the constraint is added?

What is the difference between Union and Union all statements

what is true about Delete and truncate 1. Truncate can not be used in PL/SQL 2. Delete will remove the data and will not move watermark. 3. Both statements require commit 4. truncate can remove selected records

What is the default value for the OPTIMIZER_MODE initialization parameter?

Can we have multiple primary keys in a table?

Which are the aggregate functions?

We have unique constraint on sal column on emp table. can the column accept multiple null values?

Can we have multiple check constraints on a single column of a table.

We can view the constraint details from following data dictionary views

Comparision of Decode and case statement

Evaluate the SQL statement: SELECT ROUND(45.953, -1), TRUNC(45.936, 2) FROM dual; Which values are displayed?

Which are DML statements? (Choose all that apply.)

On which line will the following command fail? INSERT INTO plsql101_product ( product_name, product_price, quantity_on_hand, last_stock_date ) VALUES ( 'New Product', 1.95, 10, TO_CHAR(USER) ) ;

Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set? A. The DESCRIBE DEPT statement displays the structure of the DEPT table. B. The ROLLBACK statement frees the storage space occupied by the DEPT table. C. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist. D. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.

Among these Which are the system variables

What would be the result of the following DECODE function? DECODE(‘B’, ‘A’, ‘One’, ‘E’, ‘Five’, ‘I’, ‘Nine’, ‘O’, ‘Fifteen’, ‘U’, ‘Twenty-one’, ‘N/A’ )

Evaluate this SQL statement: SELECT ename, sal, 12*sal+100 FROM emp; The SAL column stores the monthly salary of the employee. Which change must be made to the above syntax to calculate the annual compensation as "monthly salary plus a monthly bonus of $100, multiplied by 12"? Evaluate this SQL statement: SELECT ename, sal, 12*sal+100 FROM emp; The SAL column stores the monthly salary of the employee. Which change must be made to the above syntax to calculate the annual compensation as "monthly salary plus a monthly bonus of $100, multiplied by 12"? A. No change is required to achieve the desired results. B. SELECT ename, sal, 12*(sal+100) FROM emp; C. SELECT ename, sal, (12*sal)+100 FROM emp; D. SELECT ename, sal+100,*12 FROM emp;

Which of the following is NOT a benefit of indexes?

Which of the following commands will rename a table?