Top 30+ PL/SQL Interview Questions and Answers

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PL/SQL (Procedural Language/Structured Query Language) is Oracle’s powerful extension of SQL. It is widely used for writing complex queries, procedures, triggers, and functions within Oracle databases. Interviewers often assess PL/SQL knowledge in technical rounds for roles like PL/SQL Developer, Oracle Database Administrator, Backend Developer, Data Engineer, and Application Support Analyst. These interviews typically include a mix of theoretical concepts, coding logic, and real-world scenarios. This blog lists 30+ commonly asked PL/SQL interview questions to help you prepare confidently for multiple job profiles.

Fun Fact: Oracle claims that 97% of Fortune 100 companies use its software—most of which rely on PL/SQL.

Note: We have categorized PL/SQL interview questions into basic, fresher, experienced, advanced, scenario-based, tricky, coding, and more for easy reference. 

Basic PL/SQL Interview Questions

Here is a list of basic PL/SQL interview questions answers.

1. What is PL/SQL and how does it differ from SQL?

PL/SQL (Procedural Language/SQL) is Oracle’s extension of SQL that supports procedural features like loops, conditions, and error handling. While SQL is used for data manipulation and querying, PL/SQL allows you to write full programs that control the flow of execution, making it suitable for writing business logic directly within the database.

2. Explain the structure of a PL/SQL block.

A PL/SQL block has three main sections:

• Declaration (optional): Declare variables, constants, cursors.
• Begin (mandatory): Actual executable statements.
• Exception (optional): Error handling logic.
  Each block ends with the END; keyword.

3. What are the different data types available in PL/SQL?

Common PL/SQL data types include:

• Scalar types: NUMBER, VARCHAR2, DATE, BOOLEAN
• Composite types: RECORD, TABLE, VARRAY
• Reference types: REF CURSOR
• LOB types: CLOB, BLOB, BFILE

4. How do you handle exceptions in PL/SQL?

Exceptions are handled in the EXCEPTION block. Built-in exceptions like NO_DATA_FOUND and TOO_MANY_ROWS can be caught by name. User-defined exceptions are declared with the EXCEPTION keyword and raised using RAISE.

PL/SQL Interview Questions for Freshers

Here are some commonly asked PL/SQL interview questions and answers for freshers.

5. What is the purpose of the %TYPE and %ROWTYPE attributes in PL/SQL?

%TYPE lets a variable inherit the data type of a table column or another variable. %ROWTYPE lets a variable represent a complete row of a table or cursor, simplifying record manipulation.

6. Describe the difference between implicit and explicit cursors.

Implicit cursors are automatically created by Oracle for single SQL statements like SELECT INTO. Explicit cursors are declared and controlled manually, useful for multi-row queries where looped processing is needed.

7. What are triggers in PL/SQL and when would you use them?

Triggers are stored programs that automatically run before or after INSERT, UPDATE, or DELETE on a table. They’re used for auditing, validation, or enforcing business rules at the database level.

8. How can you declare and use a record in PL/SQL?

You can declare a record using %ROWTYPE or a custom TYPE. 

Example:

DECLARE  

   emp_rec employees%ROWTYPE;  

BEGIN  

   SELECT * INTO emp_rec FROM employees WHERE employee_id = 101;  

END;

Note: PL SQL interview topics for freshers often include basic syntax, cursors, exceptions, triggers, procedures, and functions.

Oracle PL/SQL Interview Questions for Experienced

Let’s go through the important PL/SQL interview questions for experienced candidates.

9. How do you optimize PL/SQL code for performance?

Use BULK COLLECT and FORALL for bulk processing. Minimize context switches between SQL and PL/SQL. Avoid unnecessary loops. Analyze execution plans and gather table stats regularly.

10. Explain the use of bulk collect and forall in PL/SQL.

BULK COLLECT retrieves multiple rows into a collection in one call. FORALL is used for performing DML on collections in batches. Both reduce loop overhead and improve performance.

11. What are materialized views and how do they differ from regular views?

Materialized views store query results physically and can be refreshed. Regular views are logical and fetch data from underlying tables each time. Materialized views help with reporting and data replication.

12. Discuss the concept and use of packages in PL/SQL.

Packages group related procedures, functions, variables, and cursors. They support modular design, hide implementation details, and improve performance by loading all objects at once into memory.

Note: PL SQL interview topics for experienced candidates often include performance tuning, bulk collect, ref cursors, packages, dynamic SQL, and real-time scenarios.

PL/SQL Interview Questions for 2 Years Experienced

These are some common PL/SQL interview questions experienced candidates might encounter. 

• Can you describe a challenging project you worked on involving PL/SQL?​
• How do you prioritize tasks when managing multiple PL/SQL development assignments?​
• What is the difference between a procedure and a function in PL/SQL?​

PL/SQL Interview Questions for 3 Years Experienced

If you have around three years of experience, you might come across such PL/SQL interview questions.

• Describe a situation where you had to debug a complex PL/SQL program.​
• How do you ensure code quality and maintainability in your PL/SQL applications?​
• Explain the concept of ref cursors and their usage in PL/SQL.

PL/SQL Interview Questions for 4 Years Experienced

Here are some important PL/SQL interview questions for candidates with 4 years of experience. 

• What motivates you to continue developing your PL/SQL skills?​
• How do you handle disagreements in a team regarding PL/SQL coding standards?​
• Discuss the use and benefits of autonomous transactions in PL/SQL.

Interview Questions on PL/SQL for 5 Years Experienced

Here are some common PL/SQL questions interviewers often ask to candidates with 5 years of experience. 

• Can you share an experience where your PL/SQL expertise significantly impacted a project’s success?​
• How do you mentor junior developers in PL/SQL best practices?​
• What are the considerations for using dynamic SQL in PL/SQL?

PL/SQL Interview Questions for 6 Years Experienced

Candidates with 6 years of experience might face such PL/SQL interview questions. 

• Reflect on a time when you had to learn a new PL/SQL feature quickly.​
• How do you approach performance tuning in PL/SQL applications?​
• Explain the differences between nested tables and VARRAYs in PL/SQL.

PL/SQL Interview Questions for 7 Years Experienced

These are some common PL SQL interview questions for 7 years experienced professionals. 

• What strategies do you use to stay updated with the latest PL/SQL developments?​
• Describe how you have contributed to improving PL/SQL coding standards in your team.​
• How do you implement error logging and debugging in PL/SQL applications?

PL/SQL Interview Questions for 10 Years Experienced

If you are a senior-level professional with 10 years of experience, you might encounter such PL/SQL interview questions. 

• How has your approach to PL/SQL development evolved over the past decade?​
• Can you discuss a leadership role you took on in a PL/SQL project?​
• What are the best practices for securing PL/SQL code and applications?

Advanced PL/SQL Interview Questions

Here are some advanced PL SQL interview questions and answers.

13. What is the difference between a mutating table and a constraining table?

A mutating table is one that’s being modified by a DML statement and cannot be queried from a row-level trigger. A constraining table is one involved in a referential integrity check. Oracle blocks queries on mutating tables in row-level triggers to prevent inconsistent reads.

14. How do you implement fine-grained access control in PL/SQL?

Fine-grained access control is implemented using Virtual Private Database (VPD) policies. These policies attach a function to a table that returns a predicate dynamically, restricting rows based on session context (like user role or department).

15. Explain the concept of pipelined table functions and their use cases.

Pipelined table functions return rows as they’re processed, instead of waiting for the full result set. They use PIPE ROW() inside the function and are useful for transforming large datasets or streaming results to SQL queries.

Note: Advanced PL SQL interview topics often include collections, autonomous transactions, dynamic SQL, pipelined functions, and error logging. 

Tricky PL/SQL Interview Questions

Let’s go through some tricky interview questions and answers on PL SQL. 

16. How can you update a view in PL/SQL?

A view can be updated if it is based on a single base table and doesn’t include GROUP BY, DISTINCT, or joins. For complex views, use INSTEAD OF triggers to handle updates manually.

17. What happens if a PL/SQL block contains no exception handling?

If no exception block is present and an error occurs, the block terminates immediately and the error is passed to the calling environment. In anonymous blocks, this often results in an unhandled exception message.

18. Can you commit inside a trigger? Why or why not?

No, you cannot commit inside a trigger. Oracle raises the error ORA-04092 because commits in triggers can disrupt transaction consistency and rollback behaviour. Triggers must be part of the surrounding transaction scope.

Note: PL/SQL questions in interviews can get tricky with scenario-based problems, optimization logic, nested blocks, and real-time debugging. 

PL/SQL Scenario Based Interview Questions

Here are some common PL SQL scenario based interview questions for experienced and freshers. 

19. Given a scenario where a PL/SQL procedure is running slow, how would you diagnose and improve its performance?

“I’d start by checking SQL queries within the procedure—review execution plans, indexing, and table statistics. I’d also check for unnecessary loops and consider using BULK COLLECT or FORALL to reduce context switching.”

20. How would you handle a situation where a PL/SQL function needs to return multiple values?

Use either an OUT parameter with a record or a custom object type. If returning to SQL, define a pipelined table function or use a PL/SQL collection as the return type.

21. Describe how you would implement a retry mechanism in a PL/SQL block for handling transient errors.

Use a loop with exception handling. Inside the EXCEPTION block, catch specific errors (like ORA-00054), pause with DBMS_LOCK.SLEEP, then retry a limited number of times using a counter.

PL/SQL Developer Interview Questions

These are some commonly asked interview questions for PL SQL developer roles. 

22. What tools do you use for PL/SQL development and debugging?

“Common tools include Oracle SQL Developer, TOAD, and PL/SQL Developer. For debugging, I use breakpoints, DBMS_OUTPUT, and built-in profiling packages like DBMS_PROFILER.”

23. How do you manage version control for PL/SQL code?

“I store scripts in Git repositories, use branches for features, and apply naming conventions to identify object types and versions. Integration with tools like Jenkins helps with deployments.”

24. Describe your experience with integrating PL/SQL code with external systems.

“I’ve used UTL_HTTP, UTL_FILE, and DBMS_SCHEDULER to send API calls, write files, and schedule batch processes. These tools help interact with external apps from within Oracle.”

PL/SQL Queries Interview Questions

You might also come across PL/SQL query interview questions like these. 

25. Write a PL/SQL query to find the second highest salary from an employee table.

SELECT MAX(salary)  

FROM employees  

WHERE salary < (SELECT MAX(salary) FROM employees);

26. How would you retrieve the first N records from a table without using the ROWNUM pseudo-column?

From Oracle 12c onward, use FETCH FIRST:

SELECT * FROM employees ORDER BY hire_date FETCH FIRST 5 ROWS ONLY;

Collections in PL/SQL Interview Questions

These are some important PL SQL questions interview on collections. 

27. What are associative arrays in PL/SQL and how are they different from nested tables?

Associative arrays (index-by tables) use either integer or string keys. They’re sparse and unbounded. Nested tables are dense, indexed by integer only, and can be stored in database columns. Associative arrays are used mainly in memory; nested tables can be persisted.

28. How would you use a collection in a bulk operation like FORALL?

First, load data into a collection using BULK COLLECT. Then use FORALL to apply DML statements on all elements efficiently. This minimizes context switching between SQL and PL/SQL.

Performance Tuning in PL/SQL Interview Questions

Here are some PL SQL questions interviewers ask on performance tuning. 

29. What are some common reasons for slow PL/SQL procedures, and how do you address them?

Slow performance often comes from inefficient queries, missing indexes, unnecessary loops, and frequent context switching. I check SQL plans, optimize joins, use BULK COLLECT/FORALL, and avoid row-by-row processing where possible.

30. How do you use DBMS_PROFILER or DBMS_HPROF for performance analysis?

DBMS_PROFILER tracks execution time of each line in a PL/SQL block. DBMS_HPROF provides hierarchical profiling with call stacks and time spent per subprogram. These help identify slow procedures or bottlenecks.

PL/SQL Coding Interview Questions

Let’s cover coding-related PL/SQL interview questions and their solutions. 

31. Write a PL/SQL procedure to reverse a string without using built-in functions.

CREATE OR REPLACE PROCEDURE reverse_string(p_input IN VARCHAR2, p_output OUT VARCHAR2) IS  

   v_rev VARCHAR2(1000) := ”;  

BEGIN  

   FOR i IN REVERSE 1..LENGTH(p_input) LOOP  

      v_rev := v_rev || SUBSTR(p_input, i, 1);  

   END LOOP;  

   p_output := v_rev;  

END;

32. Write a function that returns TRUE if a number is a palindrome.

CREATE OR REPLACE FUNCTION is_palindrome(n NUMBER) RETURN BOOLEAN IS  

   str VARCHAR2(100);  

   rev VARCHAR2(100) := ”;  

BEGIN  

   str := TO_CHAR(n);  

   FOR i IN REVERSE 1..LENGTH(str) LOOP  

      rev := rev || SUBSTR(str, i, 1);  

   END LOOP;  

   RETURN str = rev;  

END;

33. How do you find and remove duplicate rows using PL/SQL logic?

Use ROWID to identify duplicates:

DELETE FROM employees  

WHERE ROWID NOT IN (  

   SELECT MIN(ROWID) FROM employees GROUP BY emp_id  

);

34. Write a PL/SQL block to fetch and display employee names department-wise using nested loops.

DECLARE  

   CURSOR d_cur IS SELECT dept_id FROM departments;  

   CURSOR e_cur(p_dept_id NUMBER) IS SELECT emp_name FROM employees WHERE dept_id = p_dept_id;  

BEGIN  

   FOR d IN d_cur LOOP  

      DBMS_OUTPUT.PUT_LINE(‘Department: ‘ || d.dept_id);  

      FOR e IN e_cur(d.dept_id) LOOP  

         DBMS_OUTPUT.PUT_LINE(‘  ‘ || e.emp_name);  

      END LOOP;  

   END LOOP;  

END;

Oracle SQL and PL/SQL Interview Questions

Here are some common SQL and PL/SQL interview questions and answers divided in three categories. 

Oracle SQL PL/SQL Interview Questions for Beginners

These are some important SQL and PL SQL interview questions with answers for beginners. 

35. What is the difference between WHERE and HAVING clauses in SQL?

WHERE filters rows before grouping; HAVING filters groups after aggregation. Use WHERE with raw data, HAVING with results from GROUP BY.

36. How do you join three or more tables using SQL?

Use multiple JOIN clauses:

SELECT *  

FROM a  

JOIN b ON a.id = b.a_id  

JOIN c ON b.id = c.b_id;

SQL and PL/SQL Interview Questions for Intermediate Level

Let’s cover some intermediate level SQL PL/SQL interview questions and answers. 

37. How can you return multiple result sets from a PL/SQL procedure?

Use multiple OUT ref cursors in the procedure parameters. Each cursor returns a result set to the calling program.

38. What’s the difference between DELETE, TRUNCATE, and DROP in SQL?

• DELETE: Removes rows, can be rolled back.
• TRUNCATE: Removes all rows, faster, can’t be rolled back.
• DROP: Deletes the entire table structure.

SQL and PL/SQL Interview Questions for Experienced

These are commonly-asked SQL PL/SQL interview questions for experienced candidates. 

39. Explain how to write dynamic queries using EXECUTE IMMEDIATE.

Use EXECUTE IMMEDIATE to run SQL strings stored in variables. Useful for dynamic table names or conditions. 

Example:

EXECUTE IMMEDIATE ‘DELETE FROM ‘ || table_name;

40. What steps do you take when a PL/SQL job fails silently in a production environment?

“I check the scheduler logs using DBA_SCHEDULER_JOB_RUN_DETAILS, review the exception log table (if used), and test the job manually. I also verify privileges and parameter values passed at runtime.”

Company-Specific PL/SQL Interview Questions

Accenture PL/SQL Interview Questions

Here are some common Accenture PL/SQL interview questions for experienced and freshers. 

1. What is view?
2. How do you handle exceptions in a nested PL/SQL block?
3. What are different types of queries?
4. What’s the use of packages in large-scale projects?
5. Can you write a function that returns employee details as a record?

PL/SQL Interview Questions Infosys

These are important Infosys PL SQL interview questions for experienced and entry-level professionals. 

1. Can you discuss your experience with performance tuning in various aspects?
2. What is a mutating trigger and how can it be eliminated?
3. How do you use cursors to loop through a large dataset efficiently?
4. What are INSTEAD OF triggers and where are they useful?
5. Write a PL/SQL block to display even numbers from 1 to 100.

Note: Infosys PL SQL interview questions often include joins, procedures, exception handling, cursors, triggers, and basic optimization techniques. 

Cognizant PL/SQL Interview Questions

You must also prepare for Cognizant PL SQL interview questions for experienced and freshers. 

1. What are the features of PL/SQL?
2. What is a correlated sub query?
3. How do you handle performance issues in bulk data processing?
4. What’s the difference between AFTER and BEFORE triggers?
5. How do you implement auditing logic using PL/SQL?

Wipro PL/SQL Interview Questions for Experienced and Freshers

1. Write a query to delete duplicate rows.
2. Explain the flow of control in a PL/SQL block with multiple IF conditions.
3. How do you debug PL/SQL code without using external tools?
4. How can PL/SQL procedures be reused across different applications?

Deloitte PL/SQL Interview Questions for Experienced and Freshers

1. Do you have any experience with PL/SQL?
2. What’s the difference between procedures and anonymous blocks in PL/SQL?
3. Explain exception handling when working with cursors.
4. Write a block to find the factorial of a number using recursion.

Capgemini PL/SQL Interview Questions

1. Write a function to count vowels of a string.
2. What is the difference between DDL and DML?
3. What is the purpose of %FOUND, %NOTFOUND, %ROWCOUNT in cursors?
4. How do you schedule and monitor PL/SQL jobs using DBMS_SCHEDULER?
5. Can a PL/SQL function call DML operations?

TCS PL/SQL Interview Questions

1. What are Triggers? Explain and differentiate type of Triggers.
2. What are bind variables and how do they improve performance?
3. Write a trigger that prevents deletion of a record from the employee table on weekends.
4. Describe your approach to error logging in production-ready PL/SQL code.

HCL PL/SQL Interview Questions

1. How do you integrate Java with Oracle?
2. Can you provide examples of projects you have worked on involving PL/SQL?
3. How do you manage memory in large PL/SQL collections?
4. What’s the difference between a cursor and a ref cursor?
5. Write a PL/SQL block to calculate total salary department-wise.

CGI PL/SQL Interview Questions

1. What are the different ways to pass parameters to procedures?
2. How do you create reusable exception handlers across packages?
3. How would you handle data consistency issues in a PL/SQL transaction?

Citibank PL/SQL Interview Questions

1. Write a function to mask confidential employee data before returning results.
2. What are some real-time examples where you’ve used PL/SQL for reporting?
3. How do you implement rollback in nested PL/SQL transactions?

IBM PL/SQL Interview Questions

1. Did you ever work on query tuning and optimization?
2. How do you use BULK COLLECT with LIMIT to avoid memory issues?
3. What is a deterministic function and when would you use it?
4. Describe the life cycle of a cursor in PL/SQL.

Virtusa PL/SQL Interview Questions

1. Input an array and then print the repeating characters.
2. Can you explain encapsulation?
3. How would you merge two PL/SQL collections?
4. What are compound triggers and when are they useful?
5. Explain the use of pragma directives in PL/SQL.

Wrapping Up

With these PL/SQL interview questions, you will understand the type of questions asked in real interviews. Each question helps you prepare better and feel more confident. Take time to practice and review them carefully.

If you are searching for PL/SQL jobs in India, visit Hirist. It is a job portal made for tech professionals to find the best opportunities easily.

FAQs

How can I clear a PL/SQL interview successfully?

Study real-world examples, practice writing procedures and queries, revise exception handling, and be ready to explain your code clearly during the interview.

Who should use this list of PL/SQL interview questions?

Students, fresh graduates, and working professionals applying for roles in Oracle development, backend systems, or database management will find this helpful.

How can these questions support interview preparation?

They help you understand how questions are framed, what to expect, and how to structure your answers clearly and confidently during interviews.

Do companies really ask these PL/SQL questions in interviews?

Yes, most of these questions are based on real interview patterns used by companies like TCS, Infosys, Wipro, Capgemini, and Oracle.

Is PL/SQL still in demand in 2025?

Yes, PL/SQL is widely used in Oracle-based systems, especially in banking, telecom, and enterprise applications that require strong backend logic.

What is the salary range for PL/SQL developers in India?

According to data from AmbitionBox, PL/SQL developers in India typically earn between ₹ 3 LPA to ₹12.1 LPA, depending on experience, skills, and company location.

What’s the difference between SQL and PL/SQL in interviews?

SQL is about querying data, while PL/SQL involves writing procedures, triggers, and functions to handle complex business logic.

Which companies hire PL/SQL developers?

Companies like Oracle, TCS, Infosys, Wipro, Cognizant, Capgemini, and banks frequently hire skilled PL/SQL developers for backend roles.