Mastering MariaDB

Chapter 6. Caches

Table data and indexes are normally written on mass memories, such as disks, SSDs, or flash memories. However, accessing these media is a slow process; if the server has to do it too often, the input or output is probably the bottleneck. To avoid accessing disks, MariaDB and storage engines have several caches that a DBA should know about. The following topics will be covered in this chapter:

• The InnoDB buffer pool and doublewrite buffer
• The MyISAM key cache
• The Aria page cache
• The query and subquery cache
• The table open cache
• The main per-session buffers

Note

Before beginning our discussion on the caches, a warning is needed. Many authoritative resources, such as the MariaDB Knowledge Base or the MySQL manual, suggest dedicating a huge ...