SQL 多次返回的查询性能统计消息

Question

我是运行在 SQL Server management studio 上查询 1 并且看到它 returns 我喜欢 3 条消息，但是当内部存储过程有近 10 - 20 条消息时统计数据。发生了什么事，为什么我看到他们？

SET STATISTICS IO,TIME ON;
GO
    SELECT [UserId]
         ,[UserType]
         ,[CreateDT]
         ,[EffectiveDT]
       FROM [dbo].[People] ORDER BY [UserId]
SET STATISTICS IO,TIME OFF;
GO

我收到的消息如下

SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.
Table 'People'. Scan count 1, logical reads 155, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 143 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 0 ms.

 SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 143 ms.

查询的总耗时是 143ms + 143ms 吗？

Answer 1

见下文

set statistics time on
select * from test
set statistics time off

输出：

SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 264 ms..

现在添加打印语句和一些变量

set statistics time on

print' statistics time '
declare @a int
set @a =1

select * from test
set statistics time off

输出：

SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 1 ms.

SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 1 ms.

(59 row(s) affected)

(1 row(s) affected)

SQL Server Execution Times:
   CPU time = 0 ms,  elapsed time = 264 ms.

以上代码总执行时间为1+1+264。

希望这对它的工作原理有所帮助

SQL 多次返回的查询性能统计消息

SQL query performance statistics messages returned multiple times

sql

sql-server

query-performance