T-SQL系列之性能统计信息/数据库IO(MSSQL)

--查看性能统计信息  -

dbcc freeproccache
go
select t.text as "执行的文本", st.total_logical_reads  as "逻辑读取总次数",
st.total_physical_reads  as "物理读取总次数",
st.total_elapsed_time/1000000 as "占用的总时间",
st.total_logical_writes  as "逻辑写入总次数"
from sys.dm_exec_query_stats st
cross apply sys.dm_exec_sql_text(st.sql_handle) t
go



--查询数据库IO  

WITH IOFORDATABASE AS
(
SELECT
 DB_NAME(VFS.database_id) AS DatabaseName
,CASE WHEN smf.type = 1 THEN 'LOG_FILE' ELSE 'DATA_FILE' END AS DatabaseFile_Type
,SUM(VFS.num_of_bytes_written) AS IO_Write
,SUM(VFS.num_of_bytes_read) AS IO_Read
,SUM(VFS.num_of_bytes_read + VFS.num_of_bytes_written) AS Total_IO
,SUM(VFS.io_stall) AS IO_STALL
FROM sys.dm_io_virtual_file_stats(NULL, NULL) AS VFS
JOIN sys.master_files AS smf
  ON VFS.database_id = smf.database_id
 AND VFS.file_id = smf.file_id
GROUP BY 
 DB_NAME(VFS.database_id)
,smf.type
)
SELECT 
 --ltrim(ROW_NUMBER() OVER(ORDER BY io_stall DESC)) AS RowNumber,
 substring(DatabaseName,1,30) as DatabaseName
,DatabaseFile_Type
,ltrim(CAST(1.0 * IO_Read/ (1024 * 1024) AS DECIMAL(12, 2))) AS IO_Read_MB
,ltrim(CAST(1.0 * IO_Write/ (1024 * 1024) AS DECIMAL(12, 2))) AS IO_Write_MB
,ltrim(CAST(1. * Total_IO / (1024 * 1024) AS DECIMAL(12, 2))) AS IO_TOTAL_MB
,ltrim(CAST(IO_STALL / 1000. AS DECIMAL(12, 2))) AS IO_STALL_Seconds
,ltrim(CAST(100. * IO_STALL / SUM(IO_STALL) OVER() AS DECIMAL(10, 2))) AS IO_STALL_Pct
FROM IOFORDATABASE
ORDER BY IO_STALL_Seconds DESC;
go