DB的IO统计

对数据的IO操作，都是写入到数据库文件中，sys.dm_io_virtual_file_stats Returns I/O statistics for data and log files.

sys.dm_io_virtual_file_stats (
{ database_id | NULL }
, { file_id | NULL }
)

io_stall：Total time, in milliseconds, that users waited for I/O to be completed on the file.

size_on_disk_bytes：Number of bytes used on the disk for this file.

1，查看数据库文件的IO和等待IO完成的时间

select vfs.database_id,
    vfs.file_id,
    mf.type_desc as file_type,
    vfs.sample_ms as duration_h,
    vfs.num_of_reads as reads,
    vfs.num_of_bytes_read as read_mb,
    vfs.num_of_bytes_read as avg_read_kb,
    vfs.io_stall_read_ms/vfs.num_of_reads as avg_stall_read_ms,
    vfs.num_of_writes as writes,
    vfs.num_of_bytes_written as written_mb,
    vfs.num_of_bytes_written as avg_writted_kb,
    vfs.io_stall_write_ms/vfs.num_of_writes as avg_stall_write_ms,
    vfs.io_stall/(vfs.num_of_reads+vfs.num_of_writes) as avg_stall_ms,
    ,)) as disk_size_gb,
    ,)) as file_size_gb,
    vfs.file_handle
from sys.master_files mf
CROSS APPLY sys.dm_io_virtual_file_stats(mf.database_id,mf.file_id) as vfs
where mf.database_id=db_id()  --current db
order by avg_stall_read_ms desc ,avg_stall_write_ms desc

2，查看IO pending

select vfs.database_id,
    vfs.file_id,
    pr.io_type,
    sum(pr.io_pending_ms_ticks) as io_pending_ms,
    pr.io_pending
from sys.dm_io_virtual_file_stats(null,null) vfs
inner join sys.dm_io_pending_io_requests as pr
    on vfs.file_handle=pr.io_handle
group by vfs.database_id,
    vfs.file_id,
    pr.io_type,
    pr.io_pending
order by vfs.database_id,
    vfs.file_id

参考doc：

How It Works: sys.dm_io_pending_io_requests

sys.dm_io_virtual_file_stats (Transact-SQL)

sys.dm_io_pending_io_requests (Transact-SQL)