系统表介绍
table_handles 显示了表锁相关信息
| 列名 | 含义 |
|---|---|
| OBJECT_TYPE | 对象类型 |
| OBJECT_SCHEMA | 对象所属模式 |
| OBJECT_NAME | 对象名称 |
| OBJECT_INSTANCE_BEGIN | 监测对象的内存地址 |
| OWNER_THREAD_ID | 持有表句柄的线程编号 |
| OWNER_EVENT_ID | 打开句柄的线程编号 |
| INTERNAL_LOCK | SQL层面的表锁，枚举自（READ, READ WITH SHARED LOCKS, READ HIGH PRIORITY, READ NO INSERT, WRITE ALLOW WRITE, WRITE CONCURRENT INSERT, WRITE LOW PRIORITY, or WRITE） |
| EXTERNAL_LOCK | 存储引擎级别的锁（READ EXTERNAL OR WRITE EXTERNAL） |
实例
mysql> select * from table_handles \G;
*************************** 1. row ***************************
OBJECT_TYPE: TABLE
OBJECT_SCHEMA: dao
OBJECT_NAME: articles
OBJECT_INSTANCE_BEGIN: 140703665607936
OWNER_THREAD_ID: 0
OWNER_EVENT_ID: 0
INTERNAL_LOCK: NULL
EXTERNAL_LOCK: NULL
1 row in set (0.00 sec)