13.7.4.3 INSTALL COMPONENT Syntax

This statement installs one or more server components, which become active immediately. A component provides services that are available to the server and other components; see Section 5.5, “MySQL Server Components”. INSTALL COMPONENT requires the INSERT privilege for the mysql.component system table.

Example:

Component names are URNs that begin with file:// and indicate the base name of the file that implements the component, located in the directory named by the plugin_dir system variable. Component names do not include any platform-dependent file name suffix such as .so or .dll. (These naming details are subject to change because component name interpretation is itself performed by a service and the component infrastructure makes it possible to replace the default service implementation with alternative implementations.)

If any error occurs, the statement fails and has no effect. For example, this happens if a component name is erroneous, a named component does not exist or is already installed, or component initialization fails.

A loader service handles component loading, which includes adding installed components to the mysql.component system table that serves as a registry. For subsequent server restarts, any components listed in mysql.component are loaded by the loader service during the startup sequence. This occurs even if the server is started with the --skip-grant-tables option.

If a component depends on services not present in the registry and you attempt to install the component without also installing the component or components that provide the services on which it depends, an error occurs:

ERROR 3527 (HY000): Cannot satisfy dependency for service 'component_a'
required by component 'component_b'.

To avoid this problem, either install all components in the same statement, or install the dependent component after installing any components on which it depends.