1SELECT COUNT(@@GLOBAL.innodb_undo_directory); 2COUNT(@@GLOBAL.innodb_undo_directory) 31 41 Expected 5SET @@GLOBAL.innodb_undo_directory="/tmp"; 6ERROR HY000: Variable 'innodb_undo_directory' is a read only variable 7Expected error 'Read only variable' 8SELECT COUNT(@@GLOBAL.innodb_undo_directory); 9COUNT(@@GLOBAL.innodb_undo_directory) 101 111 Expected 12SELECT @@GLOBAL.innodb_undo_directory = VARIABLE_VALUE 13FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 14WHERE VARIABLE_NAME='innodb_undo_directory'; 15@@GLOBAL.innodb_undo_directory = VARIABLE_VALUE 161 171 Expected 18SELECT COUNT(@@GLOBAL.innodb_undo_directory); 19COUNT(@@GLOBAL.innodb_undo_directory) 201 211 Expected 22SELECT COUNT(VARIABLE_VALUE) 23FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 24WHERE VARIABLE_NAME='innodb_undo_directory'; 25COUNT(VARIABLE_VALUE) 261 271 Expected 28SELECT @@innodb_undo_directory = @@GLOBAL.innodb_undo_directory; 29@@innodb_undo_directory = @@GLOBAL.innodb_undo_directory 301 311 Expected 32SELECT COUNT(@@innodb_undo_directory); 33COUNT(@@innodb_undo_directory) 341 351 Expected 36SELECT COUNT(@@local.innodb_undo_directory); 37ERROR HY000: Variable 'innodb_undo_directory' is a GLOBAL variable 38Expected error 'Variable is a GLOBAL variable' 39SELECT COUNT(@@SESSION.innodb_undo_directory); 40ERROR HY000: Variable 'innodb_undo_directory' is a GLOBAL variable 41Expected error 'Variable is a GLOBAL variable' 42SELECT COUNT(@@GLOBAL.innodb_undo_directory); 43COUNT(@@GLOBAL.innodb_undo_directory) 441 451 Expected 46SELECT innodb_undo_directory = @@SESSION.innodb_undo_directory; 47ERROR 42S22: Unknown column 'innodb_undo_directory' in 'field list' 48Expected error 'Readonly variable' 49