Getting MySQL System Variables

List all system variables

SHOW VARIABLES\G

Get the value of a global system variable

SELECT @@global.slow_query_log;
+-------------------------+
| @@global.slow_query_log |
+-------------------------+
|                       0 |
+-------------------------+

Get the value of a system session variable

SELECT @@session.big_tables;
+----------------------+
| @@session.big_tables |
+----------------------+
|                    0 |
+----------------------+
1 row in set (0.00 sec)

Get multiple system variable values

SELECT @@global.time_format, @@global.lock_wait_timeout, @@global.aria_page_checksum;;
+----------------------+----------------------------+-----------------------------+
| @@global.time_format | @@global.lock_wait_timeout | @@global.aria_page_checksum |
+----------------------+----------------------------+-----------------------------+
| %H:%i:%s             |                   31536000 |                           1 |
+----------------------+----------------------------+-----------------------------+
1 row in set (0.00 sec)

References

• 5.1.5.2 Dynamic System Variables - This page lists all the dynamic system variables.