MariaDB Interview Questions and Answers
Intermediate / 1 to 5 years experienced level questions & answers
Ques 1. What is MariaDB, and how does it differ from MySQL?
MariaDB is a fork of MySQL, created by the original developers of MySQL. It is designed to be highly compatible with MySQL but includes additional features and performance improvements.
Ques 2. What is the role of the InnoDB storage engine in MariaDB?
InnoDB is the default storage engine in MariaDB, known for its support of ACID transactions, foreign keys, and row-level locking. It provides reliability and performance for database transactions.
Ques 3. Explain the purpose of the EXPLAIN statement in MariaDB.
The EXPLAIN statement is used to analyze and optimize the execution plan of a SQL query. It provides information about how MariaDB will execute a query, helping in performance tuning.
Ques 4. What is a stored procedure, and how can you create one in MariaDB?
A stored procedure is a precompiled collection of one or more SQL statements that can be executed as a single unit. You can create a stored procedure in MariaDB using the CREATE PROCEDURE statement.
Ques 5. Explain the concept of database normalization and its importance.
Database normalization is the process of organizing data to reduce redundancy and improve data integrity. It involves dividing tables into smaller, related tables to eliminate data anomalies. Normalization improves efficiency and reduces data duplication.
Ques 6. How do you perform a database backup and restore in MariaDB?
You can use tools like mysqldump for backup and the mysql command or other tools for restoring a MariaDB database. Additionally, there are techniques like using binary logs for point-in-time recovery.
Ques 7. What is the purpose of the MAX_EXECUTION_TIME system variable in MariaDB?
The MAX_EXECUTION_TIME system variable in MariaDB is used to limit the execution time of individual statements. If a statement exceeds the specified time limit, it is automatically terminated, preventing long-running queries from impacting the server.
Ques 8. Explain the role of the my.cnf configuration file in MariaDB. Provide an example of a configuration parameter and its purpose.
The my.cnf file is the configuration file for MariaDB. It contains settings that control the behavior of the database server. For example, the 'innodb_buffer_pool_size' parameter determines the size of the InnoDB buffer pool, which is crucial for caching data and improving performance.
Ques 9. What are triggers in MariaDB, and how are they used? Provide an example.
Triggers in MariaDB are sets of instructions that are automatically executed (or 'triggered') in response to specific events on a particular table or view. An example trigger might be one that automatically updates a 'last_modified' timestamp when a row is updated.
Ques 10. Explain the concept of ACID properties in database transactions. Why are they important?
ACID stands for Atomicity, Consistency, Isolation, and Durability—the essential properties of a reliable database transaction. These properties ensure that database transactions are executed reliably, without errors or data corruption, even in the event of system failures.
Ques 11. What is the purpose of the Aria storage engine in MariaDB?
Aria is a storage engine in MariaDB that provides support for non-transactional tables. It is suitable for read-heavy workloads and is often used for temporary or internal tables.
Ques 12. Explain the concept of full-text search in MariaDB. How can you perform a full-text search?
Full-text search in MariaDB allows searching for words and phrases within text columns. To perform a full-text search, you can use the MATCH() ... AGAINST() syntax. This feature is particularly useful for applications that require advanced text searching capabilities.
Ques 13. Explain the concept of a view in MariaDB. How is it different from a table?
A view in MariaDB is a virtual table that is based on the result of a SELECT query. Unlike a table, a view does not store data on its own but provides a way to represent complex queries or join operations as if they were a table. Views are used for simplifying query complexity and security.
Ques 14. Explain the concept of connection pooling in the context of MariaDB. Why is it used?
Connection pooling involves reusing existing database connections instead of creating new ones for each user request. It helps improve performance by reducing the overhead of establishing and closing connections, especially in applications with a high volume of short-lived connections.
Ques 15. What is the purpose of the SET TRANSACTION statement in MariaDB?
The SET TRANSACTION statement in MariaDB is used to set characteristics for the current transaction, such as isolation level and transaction access mode. It allows developers to control the behavior of transactions to meet specific requirements.
Ques 16. Explain the concept of the Query Cache in MariaDB. When is it beneficial, and are there any drawbacks?
The Query Cache in MariaDB is a mechanism for caching the results of SELECT queries, allowing subsequent identical queries to be served directly from the cache. While it can improve performance for certain scenarios, it has drawbacks such as potential contention issues and inefficiency for dynamic datasets.
Ques 17. What is the purpose of the CONNECT storage engine in MariaDB?
The CONNECT storage engine in MariaDB allows you to access data from various external sources, such as other databases, text files, or web services, as if they were MariaDB tables. It provides a unified interface for querying and manipulating diverse data sources.
Ques 18. Explain the concept of the LOCK TABLES statement in MariaDB. When is it used?
The LOCK TABLES statement in MariaDB is used to explicitly lock tables for read or write operations. It is typically used in situations where a sequence of queries needs to be executed without interference from other sessions, ensuring data consistency during a specific operation.
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