SET @global_slow_query_log = @@global.slow_query_log;
SET @global_log_output = @@global.log_output;
SET @@session.long_query_time=1;
SET @@global.log_output = 'TABLE';
'----When slow_query_log = OFF----'
SET @@global.slow_query_log = OFF;
TRUNCATE mysql.slow_log;
SELECT sleep(2);
sleep(2)
0
SELECT count(*) FROM mysql.slow_log;
count(*)
0
'----When slow_query_log = ON-----'
SET @@global.slow_query_log = ON;
TRUNCATE mysql.slow_log;
SELECT sleep(2);
sleep(2)
0
SELECT count(*) FROM mysql.slow_log;
count(*)
1
SET @@global.log_output = @global_log_output;
SET @global.slow_query_log = @global_slow_query_log;