The system database
The system database mainly contains the data dictionary tables that stores the object's metadata and system tables for other operational purposes. The system database contains a number of system tables. We will learn more about them in the coming sections.
Data dictionary tables
The data dictionary tables contains the metadata about data objects. Tables of this directory are invisible and are not read by general SQL queries such as SELECT
, SHOW TABLES
, INFORMATION_SCHEMA.TABLES
, and so on. MySQL mainly exposes the metadata using the INFORMATION_SCHEMA
option.
Grant system tables
These tables are used to manage and provide grant information of users, database and relevant privileges. MySQL 8 uses grant tables as transactional tables, not nontransactional (MyISAM
, for example) tables, so all the operations on the transaction are either completed or failed; no partial case will be made possible.
Object information system tables
These tables contains information related to the...