1. What is correlated sub-query?

Correlated sub-query is a sub-query, which has reference to the main query.

2.  What command is used to create a table by copying the structure of another table?

CREATE TABLE .. AS SELECT command

Explanation :

To copy only the structure, the WHERE clause of the SELECT command should contain a FALSE statement as in the following.
CREATE TABLE NEWTABLE AS SELECT * FROM EXISTINGTABLE WHERE 1=2;

If the WHERE condition is true, then all the rows or rows satisfying the condition will be copied to the new table.

3. Synonyms

Synonyms is the alias name for table, views, sequences & procedures and are created for reasons of Security and Convenience.

Two levels are Public - created by DBA & accessible to all the users. Private - Accessible to creator only. Advantages are referencing without specifying the owner and Flexibility to customize a more meaningful naming convention.

4. Which function is used to find the largest integer less than or equal to a specific value?

FLOOR

5. What is the main disadvantage of developing an application using an API ?

The application cannot use any special features of the backend server.

6. Which Oracle supplied package can you use to output values and messages from database triggers, stored procedures and functions within SQL*Plus?

1. DBMS_DISPLAY          2. DBMS_OUTPUT              3. DBMS_LIST              4. DBMS_DESCRIBE

7. Which three of the following are implicit cursor attributes?

•  %found
•  %too_many_rows
•  %notfound
•  %rowcount
•  %rowtype

8. Order of SQL statement execution

Where clause, Group By clause, Having clause, Order By clause & Select.

9. Savepoint

         Savepoint is a point within a particular transaction to which you may rollback without rolling back the entire transaction.

10. The most important DDL statements in SQL are:

• CREATE TABLE - creates a new database table
• ALTER TABLE   - alters (changes) a database table
• DROP TABLE    - deletes a database table
• CREATE INDEX - creates an index (search key)
• DROP INDEX    - deletes an index