set @old_concurrent_insert= @@global.concurrent_insert; set @@global.concurrent_insert= 0; SET @old_log_output = @@global.log_output; SET GLOBAL LOG_OUTPUT = 'FILE'; connect con1,localhost,root,,; connect con2,localhost,root,,; connection default; 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 TABLE_LOCKS_WAITED 0 set sql_log_bin=0; set @old_general_log = @@global.general_log; set global general_log = 'OFF'; drop table if exists t1; create table t1(n int) engine=myisam; insert into t1 values(1); select get_lock('mysqltest_lock', 100); get_lock('mysqltest_lock', 100) 1 connection con2; # Sending: update t1 set n = get_lock('mysqltest_lock', 100); connection con1; # Wait for the first UPDATE to get blocked. # Sending: update t1 set n = 3; connection default; # wait for the second UPDATE to get blocked select release_lock('mysqltest_lock'); release_lock('mysqltest_lock') 1 connection con2; # Reaping first UPDATE select release_lock('mysqltest_lock'); release_lock('mysqltest_lock') 1 connection con1; # Reaping second UPDATE show status like 'Table_locks_waited'; Variable_name Value Table_locks_waited 1 connection default; drop table t1; set global general_log = @old_general_log; disconnect con2; disconnect con1; 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 SET @save_thread_cache_size=@@thread_cache_size; SET GLOBAL thread_cache_size=3; connect con1,localhost,root,,; connect con2,localhost,root,,; connection con1; disconnect con2; 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 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 connect con2,localhost,root,,; 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 connect con3,localhost,root,,; 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 connection default; SET GLOBAL thread_cache_size=@save_thread_cache_size; disconnect con3; disconnect con2; disconnect con1; CREATE TABLE t1 ( a INT ); INSERT INTO t1 VALUES (1), (2); SELECT a FROM t1 LIMIT 1; a 1 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 2.402418 EXPLAIN SELECT a FROM t1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 2 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 2.402418 SELECT a FROM t1 UNION SELECT a FROM t1 ORDER BY a; a 1 2 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 0.000000 EXPLAIN SELECT a FROM t1 UNION SELECT a FROM t1 ORDER BY a; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 UNION t1 ALL NULL NULL NULL NULL 2 NULL UNION RESULT ALL NULL NULL NULL NULL NULL Using filesort SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 0.000000 SELECT a IN (SELECT a FROM t1) FROM t1 LIMIT 1; a IN (SELECT a FROM t1) 1 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 0.000000 SELECT (SELECT a FROM t1 LIMIT 1) x FROM t1 LIMIT 1; x 1 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 0.000000 SELECT * FROM t1 a, t1 b LIMIT 1; a a 1 1 SHOW SESSION STATUS LIKE 'Last_query_cost'; Variable_name Value Last_query_cost 5.205836 DROP TABLE t1; connect con1,localhost,root,,; show status like 'com_show_status'; Variable_name Value Com_show_status 3 show status like 'hand%write%'; Variable_name Value Handler_tmp_write 0 Handler_write 0 show status like '%tmp%'; Variable_name Value Created_tmp_disk_tables 0 Created_tmp_files 0 Created_tmp_tables 0 Handler_tmp_delete 0 Handler_tmp_update 0 Handler_tmp_write 0 Rows_tmp_read 5 show status like 'hand%write%'; Variable_name Value Handler_tmp_write 0 Handler_write 0 show status like '%tmp%'; Variable_name Value Created_tmp_disk_tables 0 Created_tmp_files 0 Created_tmp_tables 0 Handler_tmp_delete 0 Handler_tmp_update 0 Handler_tmp_write 0 Rows_tmp_read 14 show status like 'com_show_status'; Variable_name Value Com_show_status 8 rnd_diff tmp_table_diff 30 8 disconnect con1; connection default; flush status; show status like 'Com%function'; Variable_name Value Com_alter_function 0 Com_create_function 0 Com_drop_function 0 create function f1 (x INTEGER) returns integer begin declare ret integer; set ret = x * 10; return ret; end // drop function f1; show status like 'Com%function'; Variable_name Value Com_alter_function 0 Com_create_function 1 Com_drop_function 1 connect root, localhost, root,,test; connection root; create database db37908; create table db37908.t1(f1 int); insert into db37908.t1 values(1); create user mysqltest_1@localhost; grant usage,execute on test.* to mysqltest_1@localhost; create procedure proc37908() begin select 1; end | create function func37908() returns int sql security invoker return (select * from db37908.t1 limit 1)| connect user1,localhost,mysqltest_1,,test; connection user1; select * from db37908.t1; ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table `db37908`.`t1` show status where variable_name ='uptime' and 2 in (select * from db37908.t1); ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table `db37908`.`t1` show procedure status where name ='proc37908' and 1 in (select f1 from db37908.t1); ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table `db37908`.`t1` show function status where name ='func37908' and 1 in (select func37908()); ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table `db37908`.`t1` connection default; disconnect user1; disconnect root; drop database db37908; drop procedure proc37908; drop function func37908; REVOKE ALL PRIVILEGES, GRANT OPTION FROM mysqltest_1@localhost; DROP USER mysqltest_1@localhost; connect con1,localhost,root,,; connection con1; DROP PROCEDURE IF EXISTS p1; DROP FUNCTION IF EXISTS f1; CREATE FUNCTION f1() RETURNS INTEGER BEGIN DECLARE foo INTEGER; DECLARE bar INTEGER; SET foo=1; SET bar=2; RETURN foo; END $$ CREATE PROCEDURE p1() BEGIN SELECT 1; END $$ SELECT f1(); f1() 1 CALL p1(); 1 1 SELECT 9; 9 9 disconnect con1; connection default; DROP PROCEDURE p1; DROP FUNCTION f1; flush status; create table t1 (a int not null auto_increment primary key, g int, b blob); insert into t1 (g,b) values (1,'a'), (2, 'b'), (3, 'b'), (1, 'c'); select * from t1; a g b 1 1 a 2 2 b 3 3 b 4 1 c select b, count(*) from t1 group by b; b count(*) a 1 b 2 c 1 select g, count(*) from t1 group by g; g count(*) 1 2 2 1 3 1 show status like 'Row%'; Variable_name Value Rows_read 12 Rows_sent 10 Rows_tmp_read 14 show status like 'Handler%'; Variable_name Value Handler_commit 0 Handler_delete 0 Handler_discover 0 Handler_external_lock 0 Handler_icp_attempts 0 Handler_icp_match 0 Handler_mrr_init 0 Handler_mrr_key_refills 0 Handler_mrr_rowid_refills 0 Handler_prepare 0 Handler_read_first 0 Handler_read_key 9 Handler_read_last 0 Handler_read_next 0 Handler_read_prev 0 Handler_read_retry 0 Handler_read_rnd 7 Handler_read_rnd_deleted 0 Handler_read_rnd_next 23 Handler_rollback 0 Handler_savepoint 0 Handler_savepoint_rollback 0 Handler_tmp_delete 0 Handler_tmp_update 2 Handler_tmp_write 7 Handler_update 0 Handler_write 4 show status like '%tmp%'; Variable_name Value Created_tmp_disk_tables 1 Created_tmp_files 0 Created_tmp_tables 2 Handler_tmp_delete 0 Handler_tmp_update 2 Handler_tmp_write 7 Rows_tmp_read 44 drop table t1; CREATE TABLE t1 (i int(11) DEFAULT NULL, KEY i (i) ) ENGINE=MyISAM; insert into t1 values (1),(2),(3),(4),(5); flush status; select * from t1 where i=5 union select * from t1 where i=5; i 5 show status like "handler%"; Variable_name Value Handler_commit 0 Handler_delete 0 Handler_discover 0 Handler_external_lock 0 Handler_icp_attempts 0 Handler_icp_match 0 Handler_mrr_init 0 Handler_mrr_key_refills 0 Handler_mrr_rowid_refills 0 Handler_prepare 0 Handler_read_first 0 Handler_read_key 2 Handler_read_last 0 Handler_read_next 2 Handler_read_prev 0 Handler_read_retry 0 Handler_read_rnd 0 Handler_read_rnd_deleted 1 Handler_read_rnd_next 2 Handler_rollback 0 Handler_savepoint 0 Handler_savepoint_rollback 0 Handler_tmp_delete 0 Handler_tmp_update 0 Handler_tmp_write 2 Handler_update 0 Handler_write 0 drop table t1; # # MDEV-11153 - Introduce status variables for table cache monitoring and # tuning # SET @old_table_open_cache= @@table_open_cache; SET @@global.table_open_cache=10; FLUSH TABLES; FLUSH STATUS; SHOW STATUS LIKE 'Table_open_cache%'; Variable_name Value Table_open_cache_active_instances 1 Table_open_cache_hits 0 Table_open_cache_misses 0 Table_open_cache_overflows 0 SHOW STATUS LIKE 'Table_open_cache%'; Variable_name Value Table_open_cache_active_instances 1 Table_open_cache_hits 72 Table_open_cache_misses 18 Table_open_cache_overflows 8 FLUSH TABLES; FLUSH STATUS; SET @@global.table_open_cache= @old_table_open_cache; # # MDEV-14505 - Threads_running becomes scalability bottleneck # # Session status for Threads_running is currently always 1. SHOW STATUS LIKE 'Threads_running'; Variable_name Value Threads_running 1 SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME='THREADS_RUNNING'; VARIABLE_VALUE 1 FLUSH STATUS; SHOW STATUS LIKE 'Threads_running'; Variable_name Value Threads_running 1 SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME='THREADS_RUNNING'; VARIABLE_VALUE 1 # # MDEV-15915 Add Feature_json status variable. # SHOW STATUS LIKE 'Feature_json'; Variable_name Value Feature_json 0 select json_valid('123'); json_valid('123') 1 SHOW STATUS LIKE 'Feature_json'; Variable_name Value Feature_json 1 connection default; set @@global.concurrent_insert= @old_concurrent_insert; SET GLOBAL log_output = @old_log_output;