alter table performance_schema.threads add column foo integer;
ERROR 42000: Access denied for user 'root'@'localhost' to database 'performance_schema'
truncate table performance_schema.threads;
ERROR HY000: Invalid performance_schema usage
ALTER TABLE performance_schema.threads ADD INDEX test_index(PROCESSLIST_ID);
ERROR 42000: Access denied for user 'root'@'localhost' to database 'performance_schema'
CREATE UNIQUE INDEX test_index ON performance_schema.threads(PROCESSLIST_ID);
ERROR 42000: Access denied for user 'root'@'localhost' to database 'performance_schema'