SQL DECLARE@init_sum_cpu_timeint, @utilizedCpuCountint--get CPU count used by SQL ServerSELECT@utilizedCpuCount =COUNT( * )FROMsys.dm_os_schedulersWHEREstatus='VISIBLE ONLINE'--calculate the CPU usage by queries OVER a 5 sec intervalSELECT@init_sum_cpu_time =SUM(cpu_time)FROMsys.dm_exe...
For architectural information on how SQL Server processes queries, see SQL statement processing. However, in some cases where existence must be checked, a join yields better performance. Otherwise, the nested query must be processed for each result of the outer query to ensure elimination of ...
Microsoft SQL Server 2000 provides the ability to perform queries against OLE DB providers. This query is done by using theOpenQueryorOpenRowsetTransact-SQL functions or by using a query with four-part names including a linked-server name. ...
导读本文为解决SQL关联子查询问题,提出了Apply算子,用于描述SQL子查询,并给出了Apply算子向join转换的恒等式,基于这些恒等式,可以实现SQL子查询去关联。Apply算子已经应用到SQL Server7.0。 1.Apply算子Apply…
Client vs. server evaluation Tracking vs. no-tracking Load related data Split queries Complex query operators Pagination SQL queries Database functions User-defined function mapping Global query filters Query tags Comparisons with null values in queries ...
SQL Server Is a Client/Server System Client Architecture Client Interfaces Show 13 more Hal Berenson and Kalen Delaney January 2000 Summary:This article examines how Microsoft SQL Server queries are processed on the client, how the various clients interact with SQL Server, and what SQL Server does...
本主题概述了 SQL Server 变更跟踪,并介绍在 SQL Server 数据库和 SQL Server Compact 数据库之间执行双向同步的控制台应用程序。如果服务器正在运行 SQL Server 2008,则建议您使用 SQL Server 变更跟踪。如果服务器运行的是其他数据库,请参见如何使用自定义变更跟踪系统。
SQL ServerOptimizing SQL Server Query PerformanceMaciej PileckiAt a Glance:Analyzing execution plans Optimizing queries Identifying queries to tuneWhen optimizing your database server, you need to tune the performance of individual queries. This is as important as—perhaps even more important than—...
您可以使用 SQL Server 分布式查询和 OPENDATASOURCE 或 OPENROWSET 函数临时查询很少访问的 Excel 数据源,如下所示: SELECT * FROM OPENDATASOURCE('Microsoft.Jet.OLEDB.4.0', 'Data Source=c:\book1.xls;Extended Properties=Excel 8.0')...Sheet1$
-- Load aggregate data into temporary tableIF OBJECT_ID('tempdb..#AggQueries', 'U') IS NOT NULL DROP TABLE #AggQueries; SELECT cs, SUM(duration) AS total_duration, 100. * SUM(duration) / SUM(SUM(duration)) OVER() AS pct, ROW_NUMBER() OVER(ORDER BY SUM(duration) DESC) AS rnINT...