One part of the MySQL installation process is data directory initialization (see Section 3.1, “Initializing the Data Directory”). During data directory initialization, MySQL creates user accounts that should be considered reserved:
'root'@'localhost
: Used for administrative purposes. This account has all privileges, is a system account, and can perform any operation.Strictly speaking, this account name is not reserved, in the sense that some installations rename the
root
account to something else to avoid exposing a highly privileged account with a well-known name.'mysql.sys'@'localhost'
: Used as theDEFINER
forsys
schema objects. Use of themysql.sys
account avoids problems that occur if a DBA renames or removes theroot
account. This account is locked so that it cannot be used for client connections.'mysql.session'@'localhost'
: Used internally by plugins to access the server. This account is locked so that it cannot be used for client connections. The account is a system account.'mysql.infoschema'@'localhost'
: Used as theDEFINER
forINFORMATION_SCHEMA
views. Use of themysql.infoschema
account avoids problems that occur if a DBA renames or removes the root account. This account is locked so that it cannot be used for client connections.