此查询通过排除 TABLE_NAME 值为 NULL 或表名中包含斜杠 / 或点 . 的页面来提供包含系统数据的页面的大致数量，这些页面表示用户定义的表。This query provides an approximate count of pages that contain system data by excluding pages where the TABLE_NAME value is either NULL or includes a slash / or period . in the table name, which indicates a user-defined table.

mysql> SELECT COUNT(*) FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NULL OR (INSTR(TABLE_NAME, '/') = 0 AND INSTR(TABLE_NAME, '.') = 0);
+----------+
| COUNT(*) |
+----------+
|     1516 |
+----------+

此查询返回包含系统数据的页面的大致数量、缓冲池页面的总数以及包含系统数据的页面的大致百分比。This query returns the approximate number of pages that contain system data, the total number of buffer pool pages, and an approximate percentage of pages that contain system data.

mysql> SELECT
       (SELECT COUNT(*) FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NULL OR (INSTR(TABLE_NAME, '/') = 0 AND INSTR(TABLE_NAME, '.') = 0)
       ) AS system_pages,
       (
       SELECT COUNT(*)
       FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       ) AS total_pages,
       (
       SELECT ROUND((system_pages/total_pages) * 100)
       ) AS system_page_percentage;
+--------------+-------------+------------------------+
| system_pages | total_pages | system_page_percentage |
+--------------+-------------+------------------------+
|          295 |        8192 |                      4 |
+--------------+-------------+------------------------+

缓冲池中系统数据的类型可以通过查询 PAGE_TYPE 值来确定。例如，以下查询返回包含系统数据的页面中八个不同的 PAGE_TYPE 值：The type of system data in the buffer pool can be determined by querying the PAGE_TYPE value. For example, the following query returns eight distinct PAGE_TYPE values among the pages that contain system data:

mysql> SELECT DISTINCT PAGE_TYPE FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NULL OR (INSTR(TABLE_NAME, '/') = 0 AND INSTR(TABLE_NAME, '.') = 0);
+-------------------+
| PAGE_TYPE         |
+-------------------+
| SYSTEM            |
| IBUF_BITMAP       |
| UNKNOWN           |
| FILE_SPACE_HEADER |
| INODE             |
| UNDO_LOG          |
| ALLOCATED         |
+-------------------+

此查询通过计数 TABLE_NAME 值为 NOT NULL 且 NOT LIKE '%INNODB_TABLES%' 的页面来提供包含用户数据的页面的近似数量。This query provides an approximate count of pages containing user data by counting pages where the TABLE_NAME value is NOT NULL and NOT LIKE '%INNODB_TABLES%'.

mysql> SELECT COUNT(*) FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NOT NULL AND TABLE_NAME NOT LIKE '%INNODB_TABLES%';
+----------+
| COUNT(*) |
+----------+
|     7897 |
+----------+

此查询返回包含用户数据的页面的近似数量、缓冲池页面的总数以及包含用户数据的页面的近似百分比。This query returns the approximate number of pages that contain user data, the total number of buffer pool pages, and an approximate percentage of pages that contain user data.

mysql> SELECT
       (SELECT COUNT(*) FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NOT NULL AND (INSTR(TABLE_NAME, '/') > 0 OR INSTR(TABLE_NAME, '.') > 0)
       ) AS user_pages,
       (
       SELECT COUNT(*)
       FROM information_schema.INNODB_BUFFER_PAGE
       ) AS total_pages,
       (
       SELECT ROUND((user_pages/total_pages) * 100)
       ) AS user_page_percentage;
+------------+-------------+----------------------+
| user_pages | total_pages | user_page_percentage |
+------------+-------------+----------------------+
|       7897 |        8192 |                   96 |
+------------+-------------+----------------------+

此查询识别缓冲池中具有页面的用户定义表：This query identifies user-defined tables with pages in the buffer pool:

mysql> SELECT DISTINCT TABLE_NAME FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME IS NOT NULL AND (INSTR(TABLE_NAME, '/') > 0 OR INSTR(TABLE_NAME, '.') > 0)
       AND TABLE_NAME NOT LIKE '`mysql`.`innodb_%';
+-------------------------+
| TABLE_NAME              |
+-------------------------+
| `employees`.`salaries`  |
| `employees`.`employees` |
+-------------------------+

有关索引页面的信息，可以使用索引名称查询 INDEX_NAME 列。例如，以下查询返回定义在 employees.salaries 表上的 emp_no 索引的页面数量和页面总数据大小：For information about index pages, query the INDEX_NAME column using the name of the index. For example, the following query returns the number of pages and total data size of pages for the emp_no index that is defined on the employees.salaries table:

mysql> SELECT INDEX_NAME, COUNT(*) AS Pages,
ROUND(SUM(IF(COMPRESSED_SIZE = 0, @@GLOBAL.innodb_page_size, COMPRESSED_SIZE))/1024/1024)
AS 'Total Data (MB)'
FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
WHERE INDEX_NAME='emp_no' AND TABLE_NAME = '`employees`.`salaries`';
+------------+-------+-----------------+
| INDEX_NAME | Pages | Total Data (MB) |
+------------+-------+-----------------+
| emp_no     |  1609 |              25 |
+------------+-------+-----------------+

此查询返回在 employees.salaries 表上定义的所有索引的页数和页的总数据大小：This query returns the number of pages and total data size of pages for all indexes defined on the employees.salaries table:

mysql> SELECT INDEX_NAME, COUNT(*) AS Pages,
       ROUND(SUM(IF(COMPRESSED_SIZE = 0, @@GLOBAL.innodb_page_size, COMPRESSED_SIZE))/1024/1024)
       AS 'Total Data (MB)'
       FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE
       WHERE TABLE_NAME = '`employees`.`salaries`'
       GROUP BY INDEX_NAME;
+------------+-------+-----------------+
| INDEX_NAME | Pages | Total Data (MB) |
+------------+-------+-----------------+
| emp_no     |  1608 |              25 |
| PRIMARY    |  6086 |              95 |
+------------+-------+-----------------+

INNODB_BUFFER_PAGE_LRU 表保存有关 InnoDB 缓冲池中页面的信息，特别是它们的排序方式，这决定了当缓冲池满时应该淘汰哪些页面。该页面的定义与 INNODB_BUFFER_PAGE 相同，只是该表有一个 LRU_POSITION 列，而不是 BLOCK_ID 列。The INNODB_BUFFER_PAGE_LRU table holds information about the pages in the InnoDB buffer pool, in particular how they are ordered that determines which pages to evict from the buffer pool when it becomes full. The definition for this page is the same as for INNODB_BUFFER_PAGE, except this table has an LRU_POSITION column instead of a BLOCK_ID column.

该查询统计 LRU 列表中特定位置被 employees.employees 表的页面占用的数量。This query counts the number of positions at a specific location in the LRU list occupied by pages of the employees.employees table.

mysql> SELECT COUNT(LRU_POSITION) FROM INFORMATION_SCHEMA.INNODB_BUFFER_PAGE_LRU
       WHERE TABLE_NAME='`employees`.`employees`' AND LRU_POSITION < 3072;
+---------------------+
| COUNT(LRU_POSITION) |
+---------------------+
|                 548 |
+---------------------+

INNODB_BUFFER_POOL_STATS 表提供的信息类似于 SHOW ENGINE INNODB STATUS 和 InnoDB 缓冲池状态变量。The INNODB_BUFFER_POOL_STATS table provides information similar to SHOW ENGINE INNODB STATUS and InnoDB buffer pool status variables.

mysql> SELECT * FROM information_schema.INNODB_BUFFER_POOL_STATS \G
*************************** 1. row ***************************
                         POOL_ID: 0
                       POOL_SIZE: 8192
                    FREE_BUFFERS: 1
                  DATABASE_PAGES: 8173
              OLD_DATABASE_PAGES: 3014
         MODIFIED_DATABASE_PAGES: 0
              PENDING_DECOMPRESS: 0
                   PENDING_READS: 0
               PENDING_FLUSH_LRU: 0
              PENDING_FLUSH_LIST: 0
                PAGES_MADE_YOUNG: 15907
            PAGES_NOT_MADE_YOUNG: 3803101
           PAGES_MADE_YOUNG_RATE: 0
       PAGES_MADE_NOT_YOUNG_RATE: 0
               NUMBER_PAGES_READ: 3270
            NUMBER_PAGES_CREATED: 13176
            NUMBER_PAGES_WRITTEN: 15109
                 PAGES_READ_RATE: 0
               PAGES_CREATE_RATE: 0
              PAGES_WRITTEN_RATE: 0
                NUMBER_PAGES_GET: 33069332
                        HIT_RATE: 0
    YOUNG_MAKE_PER_THOUSAND_GETS: 0
NOT_YOUNG_MAKE_PER_THOUSAND_GETS: 0
         NUMBER_PAGES_READ_AHEAD: 2713
       NUMBER_READ_AHEAD_EVICTED: 0
                 READ_AHEAD_RATE: 0
         READ_AHEAD_EVICTED_RATE: 0
                    LRU_IO_TOTAL: 0
                  LRU_IO_CURRENT: 0
                UNCOMPRESS_TOTAL: 0
              UNCOMPRESS_CURRENT: 0

为了对比，下面显示了基于相同数据集的 SHOW ENGINE INNODB STATUS 输出和 InnoDB 缓冲池状态变量输出。For comparison, SHOW ENGINE INNODB STATUS output and InnoDB buffer pool status variable output is shown below, based on the same data set.

有关 SHOW ENGINE INNODB STATUS 输出的更多信息，请参见 第 17.17.3 节，“InnoDB 标准监视器和锁监视器输出”。For more information about SHOW ENGINE INNODB STATUS output, see Section 17.17.3, “InnoDB Standard Monitor and Lock Monitor Output”.

mysql> SHOW ENGINE INNODB STATUS\G
...
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 137428992
Dictionary memory allocated 579084
Buffer pool size   8192
Free buffers       1
Database pages     8173
Old database pages 3014
Modified db pages  0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 15907, not young 3803101
0.00 youngs/s, 0.00 non-youngs/s
Pages read 3270, created 13176, written 15109
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 8173, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
...

有关状态变量的描述，请参见 第 7.1.10 节，“服务器状态变量”。For status variable descriptions, see Section 7.1.10, “Server Status Variables”.

mysql> SHOW STATUS LIKE 'Innodb_buffer%';
+---------------------------------------+-------------+
| Variable_name                         | Value       |
+---------------------------------------+-------------+
| Innodb_buffer_pool_dump_status        | not started |
| Innodb_buffer_pool_load_status        | not started |
| Innodb_buffer_pool_resize_status      | not started |
| Innodb_buffer_pool_pages_data         | 8173        |
| Innodb_buffer_pool_bytes_data         | 133906432   |
| Innodb_buffer_pool_pages_dirty        | 0           |
| Innodb_buffer_pool_bytes_dirty        | 0           |
| Innodb_buffer_pool_pages_flushed      | 15109       |
| Innodb_buffer_pool_pages_free         | 1           |
| Innodb_buffer_pool_pages_misc         | 18          |
| Innodb_buffer_pool_pages_total        | 8192        |
| Innodb_buffer_pool_read_ahead_rnd     | 0           |
| Innodb_buffer_pool_read_ahead         | 2713        |
| Innodb_buffer_pool_read_ahead_evicted | 0           |
| Innodb_buffer_pool_read_requests      | 33069332    |
| Innodb_buffer_pool_reads              | 558         |
| Innodb_buffer_pool_wait_free          | 0           |
| Innodb_buffer_pool_write_requests     | 11985961    |
+---------------------------------------+-------------+