mysql常用统计语句

1、查询表的数据量大小

select table_name,(data_length + index_length)/1024/1024 as table_mb,table_rows 
from information_schema.tables 
where table_schema='数据库名';

2、MySQL查询阻塞语句

select r.trx_id waiting_trx_id, r.trx_mysql_thread_Id waiting_thread, 
       r.trx_query waiting_query, b.trx_id blocking_trx_id, 
       b.trx_mysql_thread_id blocking_thread, b.trx_query blocking_query 
  from information_schema.innodb_lock_waits w inner join information_schema.innodb_trx b on b.trx_id = w.blocking_trx_id 
  inner join information_schema.innodb_trx r on r.trx_id = w.requesting_trx_id;

3、统计数据库中访问量前10的IP

SELECT 
    SUBSTRING_INDEX(host, ':', 1) AS ip, COUNT(*)
FROM
    information_schema.processlist
GROUP BY ip
ORDER BY COUNT(*) DESC
LIMIT 10;