系统表介绍
INNODB_BUFFER_PAGE_LRU 描述了在InnoDB buffer pool中每个页的信息。特别是如何在LRU列表中排序，并如何判定哪些页需要从 buffer pool 中剔除。
| 列名 | 含义 |
|---|---|
| POOL_ID | 池标识符 |
| LRU_POSITION | 页所在LRU列表中的位置 |
| SPACE | 表空间编号 |
| PAGE_NUMBER | 页编号 |
| PAGE_TYPE | 页类型 |
| FLUSH_TYPE | 刷新类型 |
| FIX_COUNT | 使用buffer poo的线程数量 |
| IS_HASHED | 此页是否存在哈希索引 |
| NEWEST_MODIFICATION | 最新修改的LSN |
| OLDEST_MODIFICATION | 最远修改的LSN |
| ACCESS_TIME | 首次访问时间 |
| TABLE_NAME | 所属表名 |
| INDEX_NAME | 所属索引名 |
| NUMBER_RECORDS | 记录数 |
| DATA_SIZE | 所有记录大小 |
| COMPRESSED_SIZE | 压缩后的大小 |
| COMPRESSED | 是否此页被压缩 |
| IO_FIX | 是否有等待 |
| IS_OLD | 是否属于旧块的子表 |
| FREE_PAGE_CLOCK | freed_page_clock计数器的值 |
实例
mysql> select * from INNODB_BUFFER_PAGE_LRU limit 10 ;
+---------+--------------+-------+-------------+-------------+------------+-----------+-----------+---------------------+---------------------+-------------+---------------+------------+----------------+-----------+-----------------+------------+---------+--------+-----------------+
| POOL_ID | LRU_POSITION | SPACE | PAGE_NUMBER | PAGE_TYPE | FLUSH_TYPE | FIX_COUNT | IS_HASHED | NEWEST_MODIFICATION | OLDEST_MODIFICATION | ACCESS_TIME | TABLE_NAME | INDEX_NAME | NUMBER_RECORDS | DATA_SIZE | COMPRESSED_SIZE | COMPRESSED | IO_FIX | IS_OLD | FREE_PAGE_CLOCK |
+---------+--------------+-------+-------------+-------------+------------+-----------+-----------+---------------------+---------------------+-------------+---------------+------------+----------------+-----------+-----------------+------------+---------+--------+-----------------+
| 0 | 0 | 0 | 7 | SYSTEM | 1 | 0 | NO | 349473582 | 0 | 94204 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 1 | 0 | 3 | SYSTEM | 0 | 0 | NO | 0 | 0 | 94204 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 2 | 0 | 2 | INODE | 1 | 0 | NO | 13281199 | 0 | 94204 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 3 | 0 | 4 | IBUF_INDEX | 0 | 0 | NO | 0 | 0 | 94208 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 4 | 0 | 11 | INDEX | 1 | 0 | NO | 349482039 | 0 | 94208 | `SYS_INDEXES` | CLUST_IND | 34 | 2480 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 5 | 0 | 1 | IBUF_BITMAP | 0 | 0 | NO | 0 | 0 | 94208 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 6 | 0 | 5 | TRX_SYSTEM | 1 | 0 | NO | 349473572 | 0 | 94209 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 7 | 0 | 6 | SYSTEM | 1 | 0 | NO | 349482363 | 0 | 94209 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 8 | 0 | 269 | UNDO_LOG | 0 | 0 | NO | 0 | 0 | 94231 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
| 0 | 9 | 0 | 45 | SYSTEM | 1 | 0 | NO | 349482402 | 0 | 94232 | NULL | NULL | 0 | 0 | 0 | NO | IO_NONE | YES | 0 |
+---------+--------------+-------+-------------+-------------+------------+-----------+-----------+---------------------+---------------------+-------------+---------------+------------+----------------+-----------+-----------------+------------+---------+--------+-----------------+
10 rows in set (0.05 sec)