content_image/698521.jpg content_image/698522.jpg content_image/698529.jpg content_image/698531.jpg
WHERE INDEX_NAME=’emp_no’ AND TABLE_NAME = ’‘employees‘.‘salaries‘’; 

<img src='content_image/698521.jpg'>

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; 

<img src='content_image/698522.jpg'>

## Example 15.9 Querying LRU_POSITION Data in the INNODB_BUFFER_PAGE_LRU Table 

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. 

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; 

<img src='content_image/698529.jpg'>

## Example 15.10 Querying the INNODB_BUFFER_POOL_STATS Table 

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 

<img src='content_image/698531.jpg'>

