MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
Table of Contents
MySQL 8.0 includes thesysschema, a set of objects that helps DBAs and developers interpret data collected by the Performance Schema.sysschema objects can be used for typical tuning and diagnosis use cases. Objects in this schema include:
Views that summarize Performance Schema data into more easily understandable form.
Stored procedures that perform operations such as Performance Schema configuration and generating diagnostic reports.
Stored functions that query Performance Schema configuration and provide formatting services.
For new installations, thesysschema is installed by default during data directory initialization if you usemysqldwith the--initializeor--initialize-insecure选择。如果不需要,可以删除sysschema manually after initialization if it is unneeded.
The MySQL upgrade procedure produces an error if asysschema exists but has noversionview, on the assumption that absence of this view indicates a user-createdsysschema. To upgrade in this case, remove or rename the existingsysschema first.
sysschema objects have aDEFINERof'mysql.sys'@'localhost'. Use of the dedicatedmysql.sysaccount avoids problems that occur if a DBA renames or removes therootaccount.