~~REDIRECT>percona-server:features:innodb_buffer_pool_pages~~

====== Patch: innodb_show_bp ======

This patch adds the INNODB_BUFFER_POOL_CONTENT table in the INFORMATION_SCHEMA.  The table contains information about the pages in the InnoDB buffer pool.

===== Variables Provided =====

This patch provides no variables.

===== Tables Provided =====

The patch provides the following [[quickref:information_schema tables reference|INFORMATION_SCHEMA tables]]:

==== INNODB_BUFFER_POOL_CONTENT ====

This table contains information about the pages in the InnoDB buffer pool.  The columns are as follows:

^ Field        ^ Notes ^
| BLOCK_NUM    | A number that increments as the buffer pool is scanned. |
| SPACE        | The tablespace number. |
| OFFSET       | The page's offset in the file. |
| RECORDS      | The number of records in the page. |
| DATASIZE     | The size of the data in the page. |
| FLUSH_TYPE   | A flag that's set if the page is being flushed.  One of BUF_FLUSH_LRU, BUF_FLUSH_SINGLE_PAGE, BUF_FLUSH_LIST. |
| FIX_COUNT    | A count of how manyfold this block is currently bufferfixed. |
| LRU_POSITION | A value which monotonically decreases. |
| PAGE_TYPE_ID | The page type. |
| PAGE_TYPE    | The page type as an enumerated constant.  Possible values are ibuf_free_list (insert buffer free list), index (this is an index page), inode, undo_log (this is an old row version for MVCC and rollbacks). |
| INDEX_NAME   | The name of the index, if it's an index page. |
| TABLE_SCHEMA | The name of the schema, if it's an index page. |
| TABLE_NAME   | The name of the table, if it's an index page. |

**Example**

<code>
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_BUFFER_POOL_CONTENT LIMIT 1\G
*************************** 1. row ***************************
   BLOCK_NUM: 0
       SPACE: 749
      OFFSET: 39441
     RECORDS: 100
    DATASIZE: 7400
  FLUSH_TYPE: 3
   FIX_COUNT: 0
LRU_POSITION: 11346860
PAGE_TYPE_ID: 17855
   PAGE_TYPE: index
  INDEX_NAME: PRIMARY
TABLE_SCHEMA: test
  TABLE_NAME: test_table
</code>

You may see different page_type, here is info from source code:
<code>
/** File page types (values of FIL_PAGE_TYPE) @{ */
#define FIL_PAGE_INDEX          17855   /*!< B-tree node */
#define FIL_PAGE_UNDO_LOG       2       /*!< Undo log page */
#define FIL_PAGE_INODE          3       /*!< Index node */
#define FIL_PAGE_IBUF_FREE_LIST 4       /*!< Insert buffer free list */
/* File page types introduced in MySQL/InnoDB 5.1.7 */
#define FIL_PAGE_TYPE_ALLOCATED 0       /*!< Freshly allocated page */
#define FIL_PAGE_IBUF_BITMAP    5       /*!< Insert buffer bitmap */
#define FIL_PAGE_TYPE_SYS       6       /*!< System page */
#define FIL_PAGE_TYPE_TRX_SYS   7       /*!< Transaction system data */
#define FIL_PAGE_TYPE_FSP_HDR   8       /*!< File space header */
#define FIL_PAGE_TYPE_XDES      9       /*!< Extent descriptor page */
#define FIL_PAGE_TYPE_BLOB      10      /*!< Uncompressed BLOB page */
#define FIL_PAGE_TYPE_ZBLOB     11      /*!< First compressed BLOB page */
#define FIL_PAGE_TYPE_ZBLOB2    12      /*!< Subsequent compressed BLOB page */
</code>

===== Patch Information =====

|  Author/Origin|Percona, inspired by Jeremy Cole's work|
|     Bugs fixed| |
|   Dependencies| |