在标准MySQL 5.6上查询没有使用过的索引的SQL

select distinct  
    mysql.innodb_index_stats.table_name,  
    mysql.innodb_index_stats.index_name  
from  
    mysql.innodb_index_stats  
where  
    concat(mysql.innodb_index_stats.index_name,  
            mysql.innodb_index_stats.table_name) not in (select   
            concat(information_schema.statistics.index_name,  
                        information_schema.statistics.table_name)  
        from  
            information_schema.statistics)  
        and mysql.innodb_index_stats.index_name <> 'GEN_CLUST_INDEX';