如何查看innodb的相关信息
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BUFFER POOL AND MEMORY
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Total memory allocated 52873396224; in additional pool allocated 0
Dictionary memory allocated 720082
Buffer pool size 3145728
Free buffers 1033599
Database pages 1902184
Old database pages 702010
Modified db pages 398
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 49894, not young 0
0.00 /s, 0.00 non-youngs/s
Pages read 139848, created 1762336, written 255420958
0.00 reads/s, 1.00 creates/s, 181.61 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 1902184, unzip_LRU len: 0
I/O sum[0]:cur[64], unzip sum[0]:cur[0]
Total memory allocated 393216; in additional pool allocated 0
INNODB分配的内存总量为52873396224字节，也就是49GB 额外内存池没有占用多余的空间
Dictionary memory allocated 720082
数据字典内存分配了720082字节
Buffer pool size 3145728
这是buffer pool数据页的数量 一共有3145728个（总内存是3145728*16/1024/1024/1024=4915200.25）
Free buffers 1033599
空闲页的数量 (1033599*16/1024=16149)
Database pages 1902184
Old list内的数据页数
Modified db pages 398
被修改的页数 ，脏页
Pending writes: LRU 0, flush list 0, single page 0
刷新页的数量，可以分为 LRU FLUSH single
Pages read 139848, created 1762336, written 255420958
页面的读取，创建，和刷新次数
Buffer pool hit rate 1000 / 1000
缓冲池命中率，命中率越高越好。这里的命中率是100%
Pending reads 0
正在读取的页的数量
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