Oracle MCQ Questions And Answers
Oracle MCQs : This section focuses on "Basics" of Oracle. These Multiple Choice Questions (MCQ) should be practiced to improve the Oracle skills required for various interviews (campus interviews, walk-in interviews, company interviews), placements, entrance exams and other competitive examinations.
1. Oracle database is a ?
A. Centralised database
B. End-user database
C. Commercial database
D. Relational database
View Answer
Ans : D
Explanation: Oracle database is a relational database management system. It is known as Oracle database, OracleDB or simply Oracle.
2. Oracle database produced and marketed by?
A. IBM
B. Google
C. Oracle Corporation
D. Facebook
View Answer
Ans : C
Explanation: It is produced and marketed by Oracle Corporation.
3. How many editions of the Oracle database there?
A. 2
B. 3
C. 4
D. 5
View Answer
Ans : C
Explanation: There four editions of the Oracle database : Enterprise Edition, Standard Edition, Express Edition and Oracle Lite.
4. Oracle DB runs on the ?
A. Windows
B. Linux
C. Unix
D. All of the above
View Answer
Ans : D
Explanation: Oracle DB runs on the most major platforms like Windows, UNIX, Linux and Mac OS.
5. A __________ is a single field or combination of fields that contains a unique record.
A. Compound Key
B. Primary key
C. Foreign Key
D. Index
View Answer
Ans : B
Explanation: A primary key is a single field or combination of fields that contains a unique record. It must be filled. None of the field of primary key can contain a null value. A table can have only one primary key.
6. In Oracle, total number of columns cannot be more than?
A. 16
B. 32
C. 64
D. 128
View Answer
Ans : B
Explanation: In Oracle, total number of columns cannot be more than 32.
7. Which statement is used to create a table from an existing table by copying the columns of existing table?
A. CREATE TABLE new_table
AS (SELECT * FROM old_table);
B. CREATE TABLE new_table
(SELECT * FROM old_table);
C. CREATE TABLE new_table
WHERE (SELECT * FROM old_table);
D. CREATE TABLE new_table
LIKE (SELECT * FROM old_table);
View Answer
Ans : A
Explanation: Option A statement is used to create a table from an existing table by copying the columns of existing table
8. Which tables are defined and scoped to the session in which you created it?
A. Global Temporary tables
B. Global Permanent tables
C. Local Permanent tables
D. Local Temporary tables
View Answer
Ans : D
Explanation: local temporary tables are distinct within modules. These tables are defined and scoped to the session in which you created it.
9. A ________ is created by a query joining one or more tables.
A. Trigger
B. Procedure
C. Both A and B
D. View
View Answer
Ans : D
Explanation: A view is created by a query joining one or more tables.
10. Which command is used to fetch records from database?
A. Fetch
B. Select
C. Use
D. Get
View Answer
Ans : B
Explanation: Oracle select query is used to fetch records from database. For example:
SELECT * from customers;
11. Which query is used to add, modify, delete or drop colums of a table?
A. Update
B. Alter
C. Truncate
D. Drop
View Answer
Ans : B
Explanation: Oracle alter query is used to add, modify, delete or drop colums of a table.
12. Which of the following is done to give a temporary to a column or table?
A. Union
B. Intersect
C. Having
D. Aliases
View Answer
Ans : D
Explanation: In Oracle, aliasing can also be done in column name as well as in table name. Aliasing is done to give a temporary to a column or table.
13. Which clause is used to remove the duplicate records from the result set?
A. Where
B. Group by
C. Like
D. Distinct
View Answer
Ans : D
Explanation: Oracle DISTINCT clause is used to remove the duplicate records from the result set. It is only used with SELECT statement.
14. A ________ is a group of PL/SQL statements that can be called by name.
A. View
B. Trigger
C. Procedure
D. Function
View Answer
Ans : C
Explanation: A procedure is a group of PL/SQL statements that can be called by name. The call specification (sometimes called call spec) specifies a java method or a third-generation language routine so that it can be called from SQL and PL/SQL.
15. How many CREATE TRIGGER statements are there?
A. 4
B. 5
C. 6
D. 7
View Answer
Ans : C
Explanation: There are six CREATE TRIGGER statements according to their firing points : BEFORE INSERT TRIGGER, BEFORE UPDATE TRIGGER, BEFORE DELETE TRIGGER, AFTER INSERT TRIGGER, AFTER UPDATE TRIGGER and AFTER DELETE TRIGGER.
16. TRUNCATE TABLE statement is used to remove the table.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: True, TRUNCATE TABLE statement is used to remove all records from a table.
17. view is a virtual table that does not physically exist.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : A
Explanation: True, view is a virtual table that does not physically exist.
18. Which processes is an instance made of Oracle?
A. Memory processes
B. Oracle background processes
C. Data processes
D. All of the above
View Answer
Ans : D
Explanation: Oracle background processes is an instance made of Oracle.
19. Which is the smallest unit of storage in an Oracle database?
A. Segment
B. Data Block
C. Extent
D. Data File
View Answer
Ans : B
Explanation: Data Block is the smallest unit of storage in an Oracle database
20. The language used application programs to request data from the DBMS is referred to as __________
A. DDL
B. DML
C. TCL
D. TDL
View Answer
Ans : A
Explanation: Data Manipulation Language (DML) statements are used for managing data in database. DML commands are not auto-committed. It means changes made by DML command are not permanent to database, it can be rolled back.
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