Pre-General Availability Draft: 2017-07-21
MySQL Server includes a component-based infrastructure for improving server extensibility:
A component provides services that are available to the server and other components. (With respect to service use, the server is a component, equal to other components.) Components interact with each other only through the services they provide.
A loader service handles component installation and uninstallation, and also lists installed components in the
mysql.componentsystem table, which serves as a registry.
The SQL statements for component manipulation affect server
operation and the
mysql.component system table
INSTALL COMPONENTinstalls components into the server. The components become active immediately. The loader service also registers installed components in the
mysql.componenttable. For subsequent server restarts, any components listed in
mysql.componentare installed by the loader service during the startup sequence. This occurs even if the server is started with the
UNINSTALL COMPONENTdeactivates components and uninstalls them from the server. The loader service also unregisters the components from the
mysql.componenttable so that they are no longer installed during the startup sequence for subsequent server restarts.
For information about the internal implementation of components, see http://dev.mysql.com/doc/dev/mysql-server/latest/PAGE_EXTENDING.html. For example, if you intend to write your own components, this information is important for understanding how components work.