The server plugin implementation comprises several components.
SQL statements:
INSTALL PLUGIN
registers a plugin in themysql.plugin
table and loads the plugin code.UNINSTALL PLUGIN
unregisters a plugin from themysql.plugin
table and unloads the plugin code.The
WITH PARSER
clause for full-text index creation associates a full-text parser plugin with a givenFULLTEXT
index.SHOW PLUGINS
displays information about server plugins.
Command-line options and system variables:
The
--plugin-load
option enables plugins to be loaded at server startup time.The
plugin_dir
system variable indicates the location of the directory where all plugins must be installed. The value of this variable can be specified at server startup with a--plugin_dir=
option. mysql_config --plugindir displays the default plugin directory path name.dir_name
For additional information about plugin loading, see Section 5.6.1, “Installing and Uninstalling Plugins”.
Plugin-related tables:
The
INFORMATION_SCHEMA.PLUGINS
table contains plugin information.The
mysql.plugin
table lists each plugin that was installed withINSTALL PLUGIN
and is required for plugin use. For new MySQL installations, this table is created during the installation process.
The client plugin implementation is simpler:
For the
mysql_options()
C API function, theMYSQL_DEFAULT_AUTH
andMYSQL_PLUGIN_DIR
options enable client programs to load authentication plugins.There are C API functions that enable management of client plugins.
To examine how MySQL implements plugins, consult the following source files in a MySQL source distribution:
In the
include/mysql
directory,plugin.h
exposes the public plugin API. This file should be examined by anyone who wants to write a plugin library.plugin_
files provide additional information that pertains to specific types of plugins.xxx
.hclient_plugin.h
contains information specific to client plugins.In the
sql
directory,sql_plugin.h
andsql_plugin.cc
comprise the internal plugin implementation.sql_acl.cc
is where the server uses authentication plugins. These files need not be consulted by plugin developers. They may be of interest for those who want to know more about how the server handles plugins.In the
sql-common
directory,client_plugin.h
implements the C API client plugin functions, andclient.c
implements client authentication support. These files need not be consulted by plugin developers. They may be of interest for those who want to know more about how the server handles plugins.