MySQL 5.6 Reference Manual :: 20 INFORMATION_SCHEMA Tables :: 20.30 INFORMATION_SCHEMA Tables for InnoDB :: 20.30.14 The INFORMATION_SCHEMA INNODB_BUFFER_PAGE Table
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- 20.30 INFORMATION_SCHEMA Tables for InnoDB
- 20.30.1 The INFORMATION_SCHEMA INNODB_CMP and INNODB_CMP_RESET Tables
- 20.30.2 The INFORMATION_SCHEMA INNODB_CMP_PER_INDEX and INNODB_CMP_PER_INDEX_RESET Tables
- 20.30.3 The INFORMATION_SCHEMA INNODB_CMPMEM and INNODB_CMPMEM_RESET Tables
- 20.30.4 The INFORMATION_SCHEMA INNODB_TRX Table
- 20.30.5 The INFORMATION_SCHEMA INNODB_LOCKS Table
- 20.30.6 The INFORMATION_SCHEMA INNODB_LOCK_WAITS Table
- 20.30.7 The INFORMATION_SCHEMA INNODB_SYS_TABLES Table
- 20.30.8 The INFORMATION_SCHEMA INNODB_SYS_INDEXES Table
- 20.30.9 The INFORMATION_SCHEMA INNODB_SYS_COLUMNS Table
- 20.30.10 The INFORMATION_SCHEMA INNODB_SYS_FIELDS Table
- 20.30.11 The INFORMATION_SCHEMA INNODB_SYS_FOREIGN Table
- 20.30.12 The INFORMATION_SCHEMA INNODB_SYS_FOREIGN_COLS Table
- 20.30.13 The INFORMATION_SCHEMA INNODB_SYS_TABLESTATS View
- 20.30.14 The INFORMATION_SCHEMA INNODB_BUFFER_PAGE Table
- 20.30.15 The INFORMATION_SCHEMA INNODB_BUFFER_PAGE_LRU Table
- 20.30.16 The INFORMATION_SCHEMA INNODB_BUFFER_POOL_STATS Table
- 20.30.17 The INFORMATION_SCHEMA INNODB_METRICS Table
- 20.30.18 The INFORMATION_SCHEMA INNODB_FT_CONFIG Table
- 20.30.19 The INFORMATION_SCHEMA INNODB_FT_DEFAULT_STOPWORD Table
- 20.30.20 The INFORMATION_SCHEMA INNODB_FT_INDEX_TABLE Table
- 20.30.21 The INFORMATION_SCHEMA INNODB_FT_INDEX_CACHE Table
- 20.30.22 The INFORMATION_SCHEMA INNODB_FT_DELETED Table
- 20.30.23 The INFORMATION_SCHEMA INNODB_FT_BEING_DELETED Table
The INNODB_BUFFER_PAGE table holds information
about each page in the
InnoDB buffer
pool.
Table 20.14. INNODB_BUFFER_PAGE Columns
| Column name | Description |
|---|---|
POOL_ID | Buffer Pool ID. An identifier to distinguish between multiple buffer pool instances. |
BLOCK_ID | Buffer Pool Block ID. |
SPACE | Tablespace ID. Uses the same value as in
INNODB_SYS_TABLES.SPACE. |
PAGE_NUMBER | Page number. |
PAGE_TYPE | Page type string. One of allocated (Freshly allocated
page), index (B-tree node),
undo_log (Undo log page),
inode (Index node),
ibuf_free_list (Insert buffer free
list), ibuf_bitmap (Insert buffer
bitmap), system (System page),
trx_system (Transaction system data),
file_space_header (File space header),
extent_descriptor (Extent descriptor
page), blob (Uncompressed BLOB page),
compressed_blob (First compressed BLOB
page), compressed_blob2 (Subsequent
comp BLOB page), unknown (unknown). |
FLUSH_TYPE | Flush type. |
FIX_COUNT | Number of threads using this block within the buffer pool. When zero, the block is eligible to be evicted. |
IS_HASHED | Whether hash index has been built on this page. |
NEWEST_MODIFICATION | Log Sequence Number of the youngest modification. |
OLDEST_MODIFICATION | Log Sequence Number of the oldest modification. |
ACCESS_TIME | Time of first access. |
TABLE_NAME | Name of the table the page belongs to. |
INDEX_NAME | Name of the index the page belongs to. It can be the name of a clustered index or a secondary index. |
NUMBER_RECORDS | Number of records within the page. |
DATA_SIZE | Sum of the sizes of the records. |
COMPRESSED_SIZE | Compressed page size. Null for pages that are not compressed. |
PAGE_STATE | Page state. A page with valid data has one of the following states:
FILE_PAGE (buffers a page of data from
a file), MEMORY (buffers a page from an
in-memory object),
Other possible states (managed by
InnoDB) are: null,
READY_FOR_USE,
NOT_USED,
REMOVE_HASH. |
IO_FIX | Specifies whether any I/O is pending for this page:
IO_NONE = no pending I/O,
IO_READ = read pending,
IO_WRITE = write pending. |
IS_OLD | bpage->old. |
FREE_PAGE_CLOCK | bpage->freed_page_clock. |
Notes:
This table is primarily useful for expert-level performance monitoring, or when developing performance-related extensions for MySQL.
Since the
INFORMATION_SCHEMAis a general-purpose way to monitor the MySQL server, use this table rather than the correspondingInnoDBsystem table for any new monitoring application you develop.You must have the
PROCESSprivilege to query this table.
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