flush status; show status like 'Table_lock%'; Variable_name Value Table_locks_immediate 0 Table_locks_waited 0 select * from information_schema.session_status where variable_name like 'Table_lock%'; VARIABLE_NAME VARIABLE_VALUE TABLE_LOCKS_IMMEDIATE 0.0000000 TABLE_LOCKS_WAITED 0.0000000 SET SQL_LOG_BIN=0; drop table if exists t1; create table t1(n int) engine=myisam; insert into t1 values(1); lock tables t1 read; unlock tables; lock tables t1 read; update t1 set n = 3; unlock tables; show status like 'Table_lock%'; Variable_name Value Table_locks_immediate 3 Table_locks_waited 1 select * from information_schema.session_status where variable_name like 'Table_lock%'; VARIABLE_NAME VARIABLE_VALUE TABLE_LOCKS_IMMEDIATE 3.0000000 TABLE_LOCKS_WAITED 1.0000000 drop table t1; select 1; 1 1 show status like 'last_query_cost'; Variable_name Value Last_query_cost 0.000000 create table t1 (a int); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); select * from t1 where a=6; a 6 6 6 6 6 show status like 'last_query_cost'; Variable_name Value Last_query_cost 12.084449 show status like 'last_query_cost'; Variable_name Value Last_query_cost 12.084449 select 1; 1 1 show status like 'last_query_cost'; Variable_name Value Last_query_cost 0.000000 drop table t1; FLUSH STATUS; SHOW STATUS LIKE 'max_used_connections'; Variable_name Value Max_used_connections 1 SELECT * FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'max_used_connections'; VARIABLE_NAME VARIABLE_VALUE MAX_USED_CONNECTIONS 1.0000000 SET @save_thread_cache_size=@@thread_cache_size; SET GLOBAL thread_cache_size=3; SHOW STATUS LIKE 'max_used_connections'; Variable_name Value Max_used_connections 3 SELECT * FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'max_used_connections'; VARIABLE_NAME VARIABLE_VALUE MAX_USED_CONNECTIONS 3.0000000 FLUSH STATUS; SHOW STATUS LIKE 'max_used_connections'; Variable_name Value Max_used_connections 2 SELECT * FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'max_used_connections'; VARIABLE_NAME VARIABLE_VALUE MAX_USED_CONNECTIONS 2.0000000 SHOW STATUS LIKE 'max_used_connections'; Variable_name Value Max_used_connections 3 SELECT * FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'max_used_connections'; VARIABLE_NAME VARIABLE_VALUE MAX_USED_CONNECTIONS 3.0000000 SHOW STATUS LIKE 'max_used_connections'; Variable_name Value Max_used_connections 4 SELECT * FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'max_used_connections'; VARIABLE_NAME VARIABLE_VALUE MAX_USED_CONNECTIONS 4.0000000 SET GLOBAL thread_cache_size=@save_thread_cache_size; show status like 'com_show_status'; Variable_name Value Com_show_status 3 show status like 'hand%write%'; Variable_name Value Handler_write 0 show status like '%tmp%'; Variable_name Value Created_tmp_disk_tables 0 Created_tmp_files 0 Created_tmp_tables 0 show status like 'hand%write%'; Variable_name Value Handler_write 0 show status like '%tmp%'; Variable_name Value Created_tmp_disk_tables 0 Created_tmp_files 0 Created_tmp_tables 0 show status like 'com_show_status'; Variable_name Value Com_show_status 8 rnd_diff tmp_table_diff 20 8