SQL Server查看索引重建、重组索引进度

相信不少SQL Server DBA或开发人员在重建或重组大表索引时，都会至关郁闷，不知道索引重建的进度，这个对于DBA彻底是一个黑盒子，对于系统负载很是大的系统或维护窗口较短的系统，你会遇到一些挑战。例如，你建立索引的时候，不少会话被阻塞，你只能取消建立索引的任务。查看这些索引维护操做的进度、预估时间对于咱们有较大的意义，须要根据这个作一些决策。下面咱们来看看看看如何获取CREATE INDEX、ALTER INDEX REBUILD、ALTER INDEX ORGANIZE的进度。

 

 

索引重组

 

从SQL Server 2008开始，有个DMV视图sys.dm_exec_requests，里面有个字段percent_complete表示如下命令完成的工做的百分比，这里面就包括索引重组（ALTER INDEX REORGANIZE），这其中不包括ALTER INDEX REBUILD，能够查看索引重组（ALTER INDEX ORGANIZE）完成的百分比。也就是说在SQL Server 2008以前是没法获取索引重组的进度状况的。

 

percent_complete

real

Percentage of work completed for the following commands: ALTER INDEX REORGANIZE AUTO_SHRINK option with ALTER DATABASE BACKUP DATABASE DBCC CHECKDB DBCC CHECKFILEGROUP DBCC CHECKTABLE DBCC INDEXDEFRAG DBCC SHRINKDATABASE DBCC SHRINKFILE RECOVERY RESTORE DATABASE ROLLBACK TDE ENCRYPTION Is not nullable.

 

 

测试环境：SQL Server 2008 、 2017 RTM CU13

 

SELECT  er.session_id ,

        er.blocking_session_id ,

        er.status ,

        er.command ,

        DB_NAME(er.database_id) DB_name ,

        er.wait_type ,

        et.text SQLText ,

        er.percent_complete

FROM    sys.dm_exec_requests er

        CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) et

WHERE   er.session_id = 57

        AND er.session_id <> @@SPID;

 

 

 

 

 

 

 

索引重建

 

上面DMV视图sys.dm_exec_requests是否也能够查看索引重建的进度呢? 答案是不行，测试发现percent_complete这个进度一直为0，那么要如何查看索引重建（INDEX REBUILD）的进度呢？

 

不过自SQL Server 2014开始，SQL Server提供了一个新特性：sys.dm_exec_query_profiles，它能够实时监控正在执行的查询的进度状况（Monitors real time query progress while the query is in execution）。固然，须要启用实时查询监控才行。通常只需启用会话级别的实时查询监控，能够经过启用SET STATISTICS XML ON; 或SET STATISTICS PROFILE ON;开启。而从SQL Server 2016 (13.x)SP1 开始，您能够或者开启跟踪标志 7412或使用 query_thread_profile 扩展的事件。下面是官方文档的描述：

 

In SQL Server 2014 (12.x) SP2 and later use SET STATISTICS PROFILE ON or SET STATISTICS XML ON together with the query under investigation. This enables the profiling infrastructure and produces results in the DMV for the session where the SET command was executed. If you are investigating a query running from an application and cannot enable SET options with it, you can create an Extended Event using the query_post_execution_showplan event which will turn on the profiling infrastructure.

In SQL Server 2016 (13.x) SP1, you can either turn on trace flag 7412 or use the query_thread_profile extended event.

 

 

--Configure query for profiling with sys.dm_exec_query_profiles 

SET STATISTICS PROFILE ON; 

GO 

 

--Or enable query profiling globally under SQL Server 2016 SP1 or above 

DBCC TRACEON (7412, -1); 

GO

 

ALTER INDEX Your_Index_Name ON Your_Table_Name REBUILD;

GO

 

 

 

 

DECLARE @SPID INT = 53;

;WITH agg AS

(

     SELECT SUM(qp.[row_count]) AS [RowsProcessed],

            SUM(qp.[estimate_row_count]) AS [TotalRows],

            MAX(qp.last_active_time) - MIN(qp.first_active_time) AS [ElapsedMS],

            MAX(IIF(qp.[close_time] = 0 AND qp.[first_row_time] > 0,

                    [physical_operator_name],

                    N'<Transition>')) AS [CurrentStep]

     FROM sys.dm_exec_query_profiles qp

     WHERE qp.[physical_operator_name] IN (N'Table Scan', N'Clustered Index Scan', N'Sort' , N'Index Scan')

     AND   qp.[session_id] = @SPID

), comp AS

(

     SELECT *,

            ([TotalRows] - [RowsProcessed]) AS [RowsLeft],

            ([ElapsedMS] / 1000.0) AS [ElapsedSeconds]

     FROM   agg

)

SELECT [CurrentStep],

       [TotalRows],

       [RowsProcessed],

       [RowsLeft],

       CONVERT(DECIMAL(5, 2),

               (([RowsProcessed] * 1.0) / [TotalRows]) * 100) AS [PercentComplete],

       [ElapsedSeconds],

       (([ElapsedSeconds] / [RowsProcessed]) * [RowsLeft]) AS [EstimatedSecondsLeft],

       DATEADD(SECOND,

               (([ElapsedSeconds] / [RowsProcessed]) * [RowsLeft]),

               GETDATE()) AS [EstimatedCompletionTime]

FROM   comp;

 

 

 

 

注意事项：在SQL Server 2016 SP1以前，若是要使用sys.dm_exec_query_profiles查看索引重建的进度，那么就必须在索引重建以前设置SET STATISTICS PROFILE ON or SET STATISTICS XML ON。 而自

SQL Server 2016 SP1以后，可使用DBCC TRACEON (7412, -1);开启全局会话的跟踪标记，或者开启某个会话的跟踪标记，固然若是要使用sys.dm_exec_query_profiles查看索引重建的进度，也必须开启7412跟踪标记

，而后重建索引，不然也没有值。

 

注意事项：：索引重组时，sys.dm_exec_query_profiles中没有数据。因此sys.dm_exec_query_profiles不能用来查看索引重组的进度。

 

 

新建索引

 

新建索引进度的查询，也可使用下面SQL语句。这里不作展开。

 

DECLARE @SPID INT = 56;

;WITH agg AS

(

     SELECT SUM(qp.[row_count]) AS [RowsProcessed],

            SUM(qp.[estimate_row_count]) AS [TotalRows],

            MAX(qp.last_active_time) - MIN(qp.first_active_time) AS [ElapsedMS],

            MAX(IIF(qp.[close_time] = 0 AND qp.[first_row_time] > 0,

                    [physical_operator_name],

                    N'<Transition>')) AS [CurrentStep]

     FROM sys.dm_exec_query_profiles qp

     WHERE qp.[physical_operator_name] IN (N'Table Scan', N'Clustered Index Scan', N'Sort' , N'Index Scan')

     AND 

       qp.[session_id] = @SPID

), comp AS

(

     SELECT *,

            ([TotalRows] - [RowsProcessed]) AS [RowsLeft],

            ([ElapsedMS] / 1000.0) AS [ElapsedSeconds]

     FROM   agg

)

SELECT [CurrentStep],

       [TotalRows],

       [RowsProcessed],

       [RowsLeft],

       CONVERT(DECIMAL(5, 2),

               (([RowsProcessed] * 1.0) / [TotalRows]) * 100) AS [PercentComplete],

       [ElapsedSeconds],

       (([ElapsedSeconds] / [RowsProcessed]) * [RowsLeft]) AS [EstimatedSecondsLeft],

       DATEADD(SECOND,

               (([ElapsedSeconds] / [RowsProcessed]) * [RowsLeft]),

               GETDATE()) AS [EstimatedCompletionTime]

FROM   comp;

SELECT   

       node_id,

       physical_operator_name, 

       SUM(row_count) row_count, 

       SUM(estimate_row_count) AS estimate_row_count,

       CAST(SUM(row_count)*100 AS float)/SUM(estimate_row_count)  as estimate_percent_complete

FROM sys.dm_exec_query_profiles   

WHERE session_id=@SPID  

GROUP BY node_id,physical_operator_name  

ORDER BY node_id desc;

 

参考资料：

 

https://docs.microsoft.com/zh-cn/sql/relational-databases/system-dynamic-management-views/sys-dm-exec-query-profiles-transact-sql?view=sql-server-2017

https://docs.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-views/sys-dm-exec-requests-transact-sql?view=sql-server-2017

https://dba.stackexchange.com/questions/139191/sql-server-how-to-track-progress-of-create-index-command

https://support.microsoft.com/zh-cn/help/4053291/fix-sys-dm-exec-query-profiles-dmv-returns-wrong-estimate-row-count-in

https://blogs.msdn.microsoft.com/sql_pfe_blog/2016/12/22/create-index-monitoring-progress/