Syntax:
SHOW [GLOBAL | SESSION] STATUS
    [LIKE 'pattern' | WHERE expr]

SHOW STATUS provides server status information. This information also
can be obtained using the mysqladmin extended-status command. The LIKE
clause, if present, indicates which variable names to match. The WHERE
clause can be given to select rows using more general conditions, as
discussed in http://dev.mysql.com/doc/refman/5.5/en/extended-show.html.
This statement does not require any privilege. It requires only the
ability to connect to the server.
With a LIKE clause, the statement displays only rows for those
variables with names that match the pattern:

mysql> SHOW STATUS LIKE 'Key%';
+--------------------+----------+
| Variable_name      | Value    |
+--------------------+----------+
| Key_blocks_used    | 14955    |
| Key_read_requests  | 96854827 |
| Key_reads          | 162040   |
| Key_write_requests | 7589728  |
| Key_writes         | 3813196  |
+--------------------+----------+

With the GLOBAL modifier, SHOW STATUS displays the status values for
all connections to MySQL. With SESSION, it displays the status values
for the current connection. If no modifier is present, the default is
SESSION. LOCAL is a synonym for SESSION.

Some status variables have only a global value. For these, you get the
same value for both GLOBAL and SESSION. The scope for each status
variable is listed at
http://dev.mysql.com/doc/refman/5.5/en/server-status-variables.html.

Each invocation of the SHOW STATUS statement uses an internal temporary
table and increments the global Created_tmp_tables value.

URL: http://dev.mysql.com/doc/refman/5.5/en/show-status.html

