查询表锁争用情况 table_locks_waited & table_locks_immedaite

官方的解释

Table_locks_immediateThe number of times that a request for a table lock could be granted immediately.Table_locks_waitedThe number of times that a request for a table lock could not be granted immediately and a wait was needed. If this is high and you have performance problems, you should first optimize your queries, and then either split your table or tables or use replication. 

可以通过检查table_locks_waited和table_locks_immediate状态变量来分析系统上的表锁定争夺

如果table_locks_waited值比较高，则说明表级锁争用比较严重。

示例

mysql> show status like 'table%';+-----------------------+---------+| Variable_name         | Value   |+-----------------------+---------+| Table_locks_immediate | 3544190 || Table_locks_waited    | 0       |+-----------------------+---------+2 rows in set (0.00 sec)