In modern days, all the data related to a particular transaction or any process is stored in suitable databases by organizations. Giant MNCs such as Google, and Microsoft have data centers the size of football grounds, where the data is stored in the backend databases and are maintained daily. So there is a need to check the data integrity and several other features of data. Here comes the need for database testers, the people who validate the correctness and completeness of existing data in the database. So before attending a database testing interview, it is recommended to go through some of the top Database Testing Interview Questions and Answers.
Top Database Testing Interview Questions and Answers for 2022
1. Mention a few steps involved in Database Testing.
Data Validity testing, Data Integrity testing, and testing of triggers and functions.
2. Explain Database Testing.
It is a process of software testing that involves data validity and data integrity testing along with testing some other triggers and functions.
3. Is DB Testing a back-end process?
Yes, Database testing is a back-end process.
4. How many types are there in DB Testing?
There are three(3) different types of database testing.
5. What are the types of Database Testing?
Structural, Functional, and Non-Functional Testing.
6. Expand DDL.
DDL stands for Data Description Language.
7. Mention some DDL commands.
ALTER, DROP, TRUNCATE, and so on are some of the DDL commands.
8. Expand DML.
DML stands for Data Manipulation Language.
9. Mention some DML commands.
INSERT, UPDATE, LOCK, and so on are some of the DML commands.
10. Expand DCL.
DCL stands for Data Control Language
11. Mention some DCL commands.
GRANT and REVOKE are some of the DDL commands.
12. Mention some of the DB Testing tools.
Database Rider, Database Benchmark, DbUnit, and so on are some of the Database testing tools.
13. What are ACID properties?
The terms ACID stand for Atomicity, Consistency, Isolation, and Durability.
14. Define White box testing.
It is a software testing approach where the tester possesses all the knowledge about the internal structure of the program.
15. Explain Black box testing.
It is a software testing technique in which the internal structure of the program is hidden from the testers.
16. How is Database testing different from Front-end testing?
DB testing involves testing back-end components such as Databases, whereas Front–end testing involves testing the functionalities of response sheets, registration forms, and so on.
17. What is a Cursor?
A cursor is used to retrieve information and process the returned data one by one
18. What are joins in the Database?
Joins are used to combine two or more tables into a single table.
19. Mention some of the DB security Testing tools.
Vega, Web Scarab, Social Engineer Toolkit, and so on are some of the database security testing tools.
20. What is key in the database?
A key is an attribute or a collection of attributes that are used to identify or determine a row uniquely.
21. Mention the steps involved in database testing.
- Set up the environment
- Run a Test
- Observe the result
- Validate the difference between observed and expected results
- Report the significant observations
22. What are the different types of keys in a Database?
23. What are CRUD operations?
CRUD stands for Create, Read, Update, and Delete operations
24. What is Load Testing?
It is a testing technique that is used to determine the performance and behavior of the system during normal and high load situations.
25. Explain SQL injection threat.
SQLI is a common threat in databases, where malicious SQL queries are inserted into the database system to retrieve the most valuable information.
26. What is Stress Testing?
It is a testing approach used to determine the reliability and stability of software applications under difficult situations.
27. White box and Blackbox testing are under which category of DB Testing?
28. What is Trigger in SQL?
A trigger is a piece of SQL code that executes automatically in response to certain actions in tables of a database system.
29. What is indexing in a Database?
Indexing is a technique in a database system used to retrieve frequently accessed information.
30. What are the different types of Indexes?
B-Tree Index, Hash Index, and Clustered Index are different types of indexes used in database systems.
31. What is a view in Database?
A view is another method of representing the data present in one or more parent tables. A view of a table may contain a few columns and rows of the major table.
32. What is the use of an aggregate function?
An aggregate function is used to perform mathematical calculations on a set of values and returns a single numerical value.
33. Expand RDBMS?
RDBMS stands for Relational Database Management System
34. What is the difference between UNION and JOIN?
35. Define Structural Database Testing.
Structural Database Testing deals with testing the schema, rows, and columns of tables, views, and so on.
36. Explain Data Redundancy.
Data Redundancy is also known as Duplication Of Data. In a database, the duplicated data causes wastage of memory.
37. What is Normalization in a database?
Normalization is an approach used in DBMS to eliminate data redundancy which saves memory by splitting the tables into smaller ones to maintain data integrity.
38. What are the different types of Normal forms?
There are four types of Normal Forms. They are
- First Normal Form (1NF)
- Second Normal Form (2NF)
- Third Normal Form (3NF)
- Boyce Codd Normal Form (BCNF)
39. What are the types of joins in SQL?
Inner join, Outer join, Left join, and Right join are different types of join operations in SQL.
40. What is SQL?
SQL stands for Structured Query Language. It is a standard language for RDBMS.
41. What are different constraints in SQL?
- NOT NULL Constraint
- CHECK Constraint
- PRIMARY Constraint
- FOREIGN Constraint
- DEFAULT Constraint
42. Mention some advantages of DBMS.
Data security, Data independence, Data backup, and recovery facility, and so on.
43. How many operators are there in SQL?
There are different types of operators in SQL. They are
- Arithmetic Operators
- Set Operators
- Logical Operators
- Conditional Operators
44. What is self-join in SQL?
A self-join command is used to join a table to itself again.
45. Mentions some NoSQL databases.
Document databases, Graph databases, and so on are some of the widely used NoSQL databases.
46. What is a Checkpoint in DBMS?
Checkpoint is a technique in database systems where older log data is removed, taken off the system, and loaded into a permanent storage disk.
47. What is meant by the schema in database systems?
A schema is defined as the skeleton structure of all the tables present in the database. It gives a clear idea of how data is stored and organized in the tables.
48. What is an ER model?
ER model stands for Entity-Relationship model. It is a high-level representation of a database with the help of diagrams that explains the relationship between several entities in a database.
49. Mention some operations in Relational Algebra.
Select, Union, Set Difference, and so on are some of the Relational Algebra operations.
50. What is Denormalization in a database?
Denormalisation is a technique in database systems used to improve the performance of the database by adding redundant data to minimize the complex operations.
51. How many types of locks are there in a Database system?
There are two different types of locks in a database system. They are
- Shared Lock and
- Exclusive Lock
52. Is the Foreign key a Primary key for another table?
True, A key is said to be a foreign key if it is the primary key for another table.
53. How is a shared lock different from an exclusive lock?
A shared lock allows the users to only read the data, whereas with an exclusive lock the data can be read and written as well.
54. Mention some of the Load Testing tools.
Web Performance, Mercury, and Rad View are some of the Load Testing tools.
55. Which symbol is used to represent a relationship in an ER diagram?
Diamond shape symbols are used to represent a relationship between different entities in an ER diagram.
56. How many types of relationships are there in the ER diagram?
There are four different types of relationships in the ER diagram. They are
- One to One
- One to Many
- Many to One
- Many to Many
57. What are the three main components of an ER model?
Entities, Attributes, and Relationships are the three main components of an ER Model.
58. Can a Primary Key can be NULL in a table?
No, a Primary key cannot be NULL in a table. Because a primary key is used to determine a row in a table.
1. Which tools are used for database testing?
Database Rider, Database Benchmark, DbUnit, and HammerDB are some of the tools that are used for database testing.
2. What should I prepare for the database testing interview?
Gain knowledge about the DBMS concepts such as DBMS, SQL, and software testing concepts, and so on.
3. What is an SQL test?
It is a testing approach in the software industry, used to test the individual components of the database system.
4. Can Selenium be used for database testing?
No, Selenium does not support database testing.
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