1SELECT COUNT(@@GLOBAL.innodb_purge_threads); 2COUNT(@@GLOBAL.innodb_purge_threads) 31 41 Expected 5SELECT COUNT(@@innodb_purge_threads); 6COUNT(@@innodb_purge_threads) 71 81 Expected 9SET @@GLOBAL.innodb_purge_threads=1; 10ERROR HY000: Variable 'innodb_purge_threads' is a read only variable 11Expected error 'Read-only variable' 12SELECT innodb_purge_threads = @@SESSION.innodb_purge_threads; 13ERROR 42S22: Unknown column 'innodb_purge_threads' in 'field list' 14Expected error 'Read-only variable' 15SELECT @@GLOBAL.innodb_purge_threads = VARIABLE_VALUE 16FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 17WHERE VARIABLE_NAME='innodb_purge_threads'; 18@@GLOBAL.innodb_purge_threads = VARIABLE_VALUE 191 201 Expected 21SELECT COUNT(VARIABLE_VALUE) 22FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 23WHERE VARIABLE_NAME='innodb_purge_threads'; 24COUNT(VARIABLE_VALUE) 251 261 Expected 27SELECT @@innodb_purge_threads = @@GLOBAL.innodb_purge_threads; 28@@innodb_purge_threads = @@GLOBAL.innodb_purge_threads 291 301 Expected 31SELECT COUNT(@@local.innodb_purge_threads); 32ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable 33Expected error 'Variable is a GLOBAL variable' 34SELECT COUNT(@@SESSION.innodb_purge_threads); 35ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable 36Expected error 'Variable is a GLOBAL variable' 37SELECT VARIABLE_NAME, VARIABLE_VALUE 38FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 39WHERE VARIABLE_NAME = 'innodb_purge_threads'; 40VARIABLE_NAME VARIABLE_VALUE 41INNODB_PURGE_THREADS 4 42