mysql> show global variables like 'innodb_buffer_pool_size';

+-------------------------+-----------+
| Variable_name | Value |
+-------------------------+-----------+
| innodb_buffer_pool_size | 134217728 |
+-------------------------+-----------+
1 row in set (0.00 sec)

那麼如何設定該引數大小呢？首先檢視執行時buffer pool相關資料指標：

mysql> show global status like 'Innodb_buffer_pool_pages_data';
+-------------------------------+-------+
| Variable_name | Value |
+-------------------------------+-------+
| Innodb_buffer_pool_pages_data | 314 |
+-------------------------------+-------+
1 row in set (0.00 sec)

mysql> show global status like 'Innodb_buffer_pool_pages_total';
+--------------------------------+-------+
| Variable_name | Value |
+--------------------------------+-------+
| Innodb_buffer_pool_pages_total | 8191 |
+--------------------------------+-------+
1 row in set (0.00 sec)

mysql> show global status like 'Innodb_page_size';
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| Innodb_page_size | 16384 |
+------------------+-------+
1 row in set (0.00 sec)

上述三項指標的含義如下：

Innodb_buffer_pool_pages_data
The number of pages in the InnoDB buffer pool containing data. The number includes both dirty and
clean pages.

Innodb_buffer_pool_pages_total
The total size of the InnoDB buffer pool, in pages.

Innodb_page_size
InnoDB page size (default 16KB). Many values are counted in pages; the page size enables them to be
easily converted to bytes

計算Innodb_buffer_pool_pages_data/Innodb_buffer_pool_pages_total*100%
當結果 > 95% 則增加 innodb_buffer_pool_size，建議使用實體記憶體的 75%
當結果 < 95% 則減少 innodb_buffer_pool_size，

建議設定大小為： Innodb_buffer_pool_pages_data* Innodb_page_size * 1.05 / (1024*1024*1024)

命令如：SET GLOBAL innodb_buffer_pool_size= 32423423：單位kb

mysql引數之innodb_buffer_pool_size大小設定

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