Interview Questions and Answers

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.