Database Architecture

Owned by Computer Science Department
Aug 03, 2023
2 min read

Architecture describes the components of a computer system and the relationships between components. This section describes MySQL architecture. Other relational databases have similar components, but component details and relationships vary greatly.

When we talk about database architecture, we're essentially referring to the design of the database system: how it's structured, what components it has, and how these components interact with one another.

MySQL follows a client-server model. The main components are:

  1. Clients: These are the interfaces or applications that interact with the MySQL server. Clients can be command-line tools, graphical interfaces, or other servers. They send SQL queries to the server and receive results.

  2. MySQL Server: This is the heart of MySQL. It processes all SQL commands and manages databases, tables, and data. It consists of multiple layers such as connection handling, query parsing and optimization, and storage engines.

The server has several layers:

  • Connection Layer: This layer handles network connections from clients and security authentications. Once connections are established, it listens for SQL queries from clients.

  • Query Layer: This layer parses SQL queries, checks them for errors, and preprocesses them before execution. It's also responsible for optimizing the queries to ensure that they are executed as efficiently as possible. This includes determining the best order in which to join tables and deciding which indexes to use.

  • Storage Engine Layer: MySQL uses a plug-in storage engine architecture which allows the database system to be more flexible. A storage engine is a software module that MySQL uses to create, read, update data from a database. The most common storage engines are InnoDB and MyISAM. Different storage engines provide different levels of functionality, performance, and reliability.

Other components of the MySQL architecture include:

  1. Physical Storage: This refers to how data is actually stored on the disk. Data can be stored in different formats based on the storage engine.

  2. Logs: MySQL maintains various types of logs (Error Log, General Query Log, Binary Log, Slow Query Log) which are essential for data recovery, troubleshooting, replication, and optimization.

Understanding the architecture of a database system can help you make the most efficient use of it and troubleshoot any issues that arise.