MySQL - SHOW ENGINE 語句

MySQL SHOW ENGINE 語句

MySQL SHOW ENGINE 語句顯示有關指定引擎的操作資訊。

語法

以下是 MySQL SHOW ENGINE 語句的語法：

SHOW ENGINE engine_name {STATUS | MUTEX}

示例

以下查詢顯示引擎 INNODB 的狀態。

SHOW ENGINE INNODB STATUS\G;

輸出

上述 mysql 查詢產生以下輸出：

*************** 1. row ***************
  Type: InnoDB
  Name:
Status:
=====================================
2021-05-15 12:06:23 0x2dd8 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 10 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 8 srv_active, 0 srv_shutdown, 3265 srv_idle
srv_master_thread log flush and writes: 0
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 42
OS WAIT ARRAY INFO: signal count 42
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
------------
TRANSACTIONS
------------
Trx id counter 69645
Purge done for trx's n:o < 69640 undo n:o < 0 state: running but idle
History list length 0
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
--------
FILE I/O
--------
I/O thread 0 state: wait Windows aio (insert buffer thread)
I/O thread 1 state: wait Windows aio (log thread)
I/O thread 2 state: wait Windows aio (read thread)
I/O thread 3 state: wait Windows aio (read thread)
I/O thread 4 state: wait Windows aio (read thread)
I/O thread 5 state: wait Windows aio (read thread)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 0 merges
merged operations:
insert 0, delete mark 0, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
---
LOG
---
Log sequence number        62802072
Log buffer assigned up to  62802072
Log buffer completed up to 62802072
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 8585216
Dictionary memory allocated 391033
Buffer pool size   512
Free buffers       255
Database pages     256
Old database pages 0
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=13048, Main thread ID=0000000000001D90 , state=sleeping
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
----------------------------
END OF INNODB MONITOR OUTPUT
============================

示例

以下查詢顯示引擎 PERFORMANCE_SCHEMA 的狀態：

SHOW ENGINE PERFORMANCE_SCHEMA STATUS\G;

輸出

執行上述查詢後，將產生以下輸出：

*************** 1. row ***************
  Type: performance_schema
  Name: events_waits_current.size
Status: 168
*************** 2. row ***************
  Type: performance_schema
  Name: events_waits_current.count
Status: 1536
*************** 3. row ***************
  Type: performance_schema
  Name: events_waits_history.size
Status: 168
*************** 4. row ***************
  Type: performance_schema
  Name: events_waits_history.count
Status: 2560
*************** 5. row ***************
  Type: performance_schema
  Name: events_waits_history.memory
Status: 430080
*************** 6. row ***************
  Type: performance_schema
  Name: events_waits_history_long.size
Status: 168
*************** 7. row ***************
  Type: performance_schema
  Name: events_waits_history_long.count
Status: 10000
*************** 8. row ***************
  Type: performance_schema
  Name: events_waits_history_long.memory
Status: 1680000
*************** 9. row ***************
  Type: performance_schema
  Name: (pfs_mutex_class).size
Status: 256
*************** 10. row ***************
  Type: performance_schema
  Name: (pfs_mutex_class).count
Status: 350
*************** 11. row ***************
  Type: performance_schema
  Name: (pfs_mutex_class).memory
Status: 89600
*************** 12. row ***************
  Type: performance_schema
  Name: (pfs_rwlock_class).size
Status: 256
*************** 13. row ***************
  Type: performance_schema
  Name: (pfs_rwlock_class).count
Status: 60
*************** 14. row ***************
  Type: performance_schema
  Name: (pfs_rwlock_class).memory
Status: 15360
*************** 15. row ***************
  Type: performance_schema
  Name: (pfs_cond_class).size
Status: 256
*************** 16. row ***************
  Type: performance_schema
  Name: (pfs_cond_class).count
Status: 150
*************** 17. row ***************
  Type: performance_schema
  Name: (pfs_cond_class).memory
Status: 38400
*************** 18. row ***************
  Type: performance_schema
  Name: (pfs_thread_class).size
Status: 256
*************** 19. row ***************
  Type: performance_schema
  Name: (pfs_thread_class).count
Status: 100
************** 20. row ***************
  Type: performance_schema
  Name: (pfs_thread_class).memory
Status: 25600
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