28 April, 2025 admin 0 Comments 1 category

Preparing for an Oracle job interview? Whether you are applying for a Database Administrator (DBA), Developer, or Analyst role, understanding the most common oracle interview questions and answers is crucial.
This guide will equip you with everything you need to impress your interviewer and secure your dream role.

Let’s dive into the most essential Oracle interview topics!

What is Oracle?

Oracle is a multinational company best known for its database software. The Oracle Database is one of the most popular relational database management systems (RDBMS) globally, widely used in enterprise applications for managing and storing data efficiently.

People Also Ask: Oracle Interview Questions and Answers

1. What is Oracle Database?
Oracle Database is a multi-model database management system, primarily used for running online transaction processing (OLTP), data warehousing, and mixed (OLTP & DW) database workloads.

2. What are the key features of Oracle Database?

  • Scalability
  • High Availability
  • Security
  • Backup and Recovery
  • Advanced Analytics

3. What is a Tablespace in Oracle?
Tablespace is a logical storage unit in Oracle Database that contains datafiles and organizes the data storage.

4. What is a Schema in Oracle?
A schema is a collection of database objects like tables, views, indexes, etc., owned by a specific user.

5. What is the difference between a Table and a View?

  • Table stores data physically.
  • View is a virtual table created using a query.

6. What is an Index in Oracle?
An Index improves the speed of data retrieval from a database table at the cost of additional writes and storage space.

7. What is the difference between a Primary Key and a Unique Key?

  • Primary Key cannot have NULLs and uniquely identifies records.
  • Unique Key also ensures uniqueness but allows a single NULL value.

8. What are Joins in Oracle SQL?
Joins combine rows from two or more tables based on a related column:

  • Inner Join
  • Left Join
  • Right Join
  • Full Outer Join

9. What is a Cursor in Oracle PL/SQL?
A Cursor is a pointer to the context area for executing SQL statements. It can be implicit or explicit.

10. What are the types of Cursors?

  • Implicit Cursor
  • Explicit Cursor

11. What is a Trigger in Oracle?
A Trigger is a stored procedure that runs automatically when specific events occur in the database.

12. What is a Stored Procedure?
A Stored Procedure is a precompiled collection of SQL statements that perform a specific task.

13. How is a Function different from a Procedure in Oracle?

  • Function returns a value and can be used in SQL expressions.
  • Procedure does not necessarily return a value.

14. What is Oracle RAC?
Oracle Real Application Clusters (RAC) allow multiple computers to run Oracle RDBMS software simultaneously while accessing a single database, providing high availability and scalability.

15. What is the purpose of the Oracle Listener?
The Listener manages the connection requests between client applications and the Oracle database server.

16. What is a Sequence in Oracle?
A Sequence generates numeric values according to specified rules, commonly used to create unique primary key values.

17. What is Normalization?
Normalization is a database design technique that reduces redundancy and improves data integrity.

18. What is Denormalization?
Denormalization is the process of introducing redundancy into a database to improve read performance.

19. What is a Deadlock in Oracle?
A Deadlock occurs when two or more sessions block each other by holding locks that the others need.

20. What are Materialized Views?
Materialized Views store the result of a query physically and refresh it periodically, improving query performance.

21. What is Oracle Data Guard?
Oracle Data Guard ensures high availability, data protection, and disaster recovery by maintaining standby copies of production databases.

22. What is a Savepoint in Oracle Database?
Savepoints allow you to roll back a transaction partially to a specific point, instead of rolling it back completely.

23. What is the difference between DELETE and TRUNCATE commands?

  • DELETE removes rows one by one and logs them.
  • TRUNCATE removes all rows instantly without logging individual row deletions.

24. How do you tune SQL queries in Oracle?

  • Use indexes
  • Avoid unnecessary columns in SELECT
  • Use EXISTS instead of IN where appropriate
  • Analyze execution plans

25. What is Oracle Partitioning?
Partitioning improves query performance by dividing large tables into smaller, more manageable pieces.

Final Tips to Crack Your Oracle Interview

  • Brush up your SQL, PL/SQL, and Oracle architecture concepts.
  • Practice writing stored procedures, functions, and complex queries.
  • Understand Oracle database administration basics if you are applying for DBA roles.

Mastering these oracle interview questions and answers will give you the confidence to face any level of Oracle interview, whether beginner, intermediate, or expert.

Good luck with your interview journey!

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