show engines 和 show engine 显示存储引擎信息

show [storage] engines

显示数据库支持的存储引擎和默认存储引擎。实例：

mysql> show storage engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
| FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
9 rows in set (0.00 sec)

也可以忽略 storage，直接使用 show engines。

mysql广告位

show engine engine_name {status | mutex}

显示存储引擎的详细信息。实例：使用 status 选项查看引擎的状态。如下：

mysql> show engine InnoDB status \G
*************************** 1. row ***************************
  Type: InnoDB
  Name:
Status:
=====================================
2020-03-13 11:23:28 0x1700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 15 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 600 srv_active, 0 srv_shutdown, 96511 srv_idle
srv_master_thread log flush and writes: 97109
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 1970
OS WAIT ARRAY INFO: signal count 1869
RW-shared spins 0, rounds 2406, OS waits 1191
RW-excl spins 0, rounds 333, OS waits 0
RW-sx spins 0, rounds 0, OS waits 0
Spin rounds per wait: 2406.00 RW-shared, 333.00 RW-excl, 0.00 RW-sx
...

上面使用 \G 格式化输出。

使用 mutex 查看存储引擎的互斥量。实例：

mysql> show engine InnoDB mutex;
+--------+-----------------------------+------------+
| Type   | Name                        | Status     |
+--------+-----------------------------+------------+
| InnoDB | rwlock: dict0dict.cc:1184   | waits=82   |
| InnoDB | rwlock: log0log.cc:844      | waits=1058 |
| InnoDB | sum rwlock: buf0buf.cc:1457 | waits=51   |
+--------+-----------------------------+------------+
3 rows in set (0.00 sec)