1SET @start_value = @@global.slow_query_log_always_write_time; 2SELECT @start_value; 3@start_value 410 5SET @@global.slow_query_log_always_write_time = DEFAULT; 6SELECT @@global.slow_query_log_always_write_time = 10; 7@@global.slow_query_log_always_write_time = 10 81 9SET @@global.slow_query_log_always_write_time = 0; 10SELECT @@global.slow_query_log_always_write_time; 11@@global.slow_query_log_always_write_time 120.000000 13SET @@global.slow_query_log_always_write_time = 700; 14SELECT @@global.slow_query_log_always_write_time; 15@@global.slow_query_log_always_write_time 16700.000000 17SET @@global.slow_query_log_always_write_time = 0.7; 18SELECT @@global.slow_query_log_always_write_time; 19@@global.slow_query_log_always_write_time 200.700000 21SET GLOBAL slow_query_log_always_write_time = @start_value; 22