The INNODB_BUFFER_POOL_STATS  table provides much of the same buffer pool information provided in SHOW ENGINE INNODB STATUS  output. Much of the same information may also be obtained using InnoDB  buffer pool server status variables. 

The idea of making pages in the buffer pool “young”  or “not young”  refers to transferring them between the sublists at the head and tail of the buffer pool data structure. Pages made “young”  take longer to age out of the buffer pool, while pages made “not young”  are moved much closer to the point of eviction. 

For related usage information and examples, see Section 15.15.5, “InnoDB INFORMATION_SCHEMA Buffer Pool Tables” . 

The INNODB_BUFFER_POOL_STATS  table has these columns: 

• POOL_ID 

The buffer pool ID. This is an identifier to distinguish between multiple buffer pool instances. 

• POOL_SIZE 

The InnoDB  buffer pool size in pages. 

• FREE_BUFFERS 

The number of free pages in the InnoDB  buffer pool. 

• DATABASE_PAGES 

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

• OLD_DATABASE_PAGES 

The number of pages in the old  buffer pool sublist. 

• MODIFIED_DATABASE_PAGES 

The number of modified (dirty) database pages. 

• PENDING_DECOMPRESS 

The number of pages pending decompression. 

• PENDING_READS 

The number of pending reads. 

• PENDING_FLUSH_LRU 

The number of pages pending flush in the LRU. 

• PENDING_FLUSH_LIST 

The number of pages pending flush in the flush list. 

• PAGES_MADE_YOUNG 

The number of pages made young. 

• PAGES_NOT_MADE_YOUNG 

