Database Reference
In-Depth Information
mysql>
SELECT @@GLOBAL.secure_auth, @@SESSION.sql_mode;
+----------------------+--------------------+
| @@GLOBAL.secure_auth | @@SESSION.sql_mode |
+----------------------+--------------------+
| 1 | STRICT_ALL_TABLES |
+----------------------+--------------------+
References to system variables using
@@
syntax with no
GLOBAL.
or
SESSION.
modifier
access the session value if there is one, or the global value otherwise.
Other ways to access system variables include the
SHOW
VARIABLES
statement and se‐
lecting from the
INFORMATION_SCHEMA
GLOBAL_VARIABLES
and
SESSION_VARIABLES
tables.
If a setting exists only as a command option with no corresponding system variable,
you cannot check its value at runtime. Fortunately, such options are rare. Nowadays,
most new settings are created as system variables that can be examined at runtime.
22.2. Managing the Plug-In Interface
Problem
You want to exploit the capabilities offered by certain server plug-ins.
Solution
Learn how to control the plug-in interface.
Discussion
MySQL supports the use of plug-ins that extend server capabilities. There are plug-ins
that implement storage engines, authentication methods, password policy,
INFORMA
TION_SCHEMA
tables, and more. The server enables you to specify which plug-ins to use,
so that you can load just those you want, with no memory or processing overhead
incurred for plug-ins you don't want.
This section provides the general background on controlling which plug-ins the server
loads. Discussion elsewhere describes specific plug-ins and what they can do for you,
including the authentication plug-ins (see
Recipe 23.1
), and
validate_password
(see
Recipes
23.3
and
23.4
).
The examples here refer to plug-in files using the
.so
(“shared object”) filename suffix.
If the suffix differs on your system, adjust the names accordingly (for example,
use
.dll
on Windows). If you don't know the name of a given plug-in file, look in the
directory named by the
plugin_dir
system variable, which is where the server expects
to find plug-in files. For example:
