with nolock in sql server performance

What exactly does NOLOCK in SQL Server mean?Typically used in such statements: SELECT * from T with (NOLOCK)Nolock is a non-locking query. Ability to read data locked by transactions, also known as dirty reads.Description:causes the current session's query to be blocked by t

SQL Server data insertion performance note, SQL Server Insert NOTE I haven't paid much attention to SQL Performance for a long time. Because the recent project neither has tens of milli

Label:The IO performance of SQL Server is affected by the IO latency of the physical disk and the IO operations performed internally by SQL Server. When monitoring disk performance, the primary measure (metric) is IO latency, whic

20150500 Union All Select [Commitid] ,[Authorid] ,[CreatedDate] ,[Createddatekey] fromDb2.tdw.dbo.commits C with(NOLOCK)whereC.[Createddatekey] between 20150500 and 20150900 with Check OPTION; GO 2, query performance test Test1, using the basic table test, cost:16s Select Count (0) from dbo.commits_total C with (nolock) whereDay (c.[ c

I. Preface After the new installation of SQL Server 2005/2008, We need to configure SQL Server Based on the server's hardware and software facilities to achieve better performance. However, the default configuration is used in most cases. Ii. Configuration 1.

Tags: time interval fetch number release operation rebuild file GIF world loadThe IO performance of SQL Server is affected by the IO latency of the physical disk and the IO operations performed internally by SQL Server. When monitoring disk

The impact of Tempdb on SQL Server performance optimization and tempdb Performance Optimization First, consolidate the basic knowledge of tempdb. Introduction: Tempdb is an important part of SQLServer, which is used to store temporary objects. Tempdb is an SQL

parameter mode, what problems the automation parameters will bring, and how to solve them.The problem itself is very simple, if you do not notice still occasionally will appear confused. Off Topic Have a little feeling very deep, that is, more and more practical problems, have to have theoretical knowledge to support,But it is often theoretically said that the situation does not appear frequently or even if there is no attention, there is time to neglect some theoretical knowledge.For the prob

very deep, that is, more and more practical problems, have to have theoretical knowledge to support,But it is often theoretically said that the situation does not appear frequently or even if there is no attention, there is time to neglect some theoretical knowledge.For the problems encountered, if you really want to find out, still have some theoretical knowledge to do the groundwork. Many times, often after encountering problems, recalled once good seems to have seen this aspect of theoretica

SQL Server focuses on optimization of Stored Procedure performance, data compression, and page compression to improve IO performance (I ). Preface The SQL Server basic series is not over yet, And the last point is not written, and

. SQL Server Execution Time: CPU time = 17188 milliseconds, time consuming = 17261 milliseconds. (1 rows affected) SQL Server Execution Time: CPU time = 0 milliseconds, time consuming = 0 milliseconds. */ Comparing 2000 and 2008 can be found 2008 CPU time is significantly higher than 2000, 2008 work

Tags: Microsoft CTI object Complex problem: Lis use parameter BinThis article belongs to theUnderstand the mysteries of performance-slow in applications, fast in SSMS"seriesNext: Understanding the Mysteries of performance-application slow, SSMs fast (5)--case: How to deal with parameter sniffing We put aside the argument sniffing topic and went back to the original point of concern in this series: Why is th

very deep, that is, more and more practical problems, have to have theoretical knowledge to support,But it is often theoretically said that the situation does not appear frequently or even if there is no attention, there is time to neglect some theoretical knowledge.For the problems encountered, if you really want to find out, still have some theoretical knowledge to do the groundwork. Many times, often after encountering problems, recalled once good seems to have seen this aspect of theoretica

Windows Server 2008 R2 en enterprise 64bitSQL Server 2008 R2 en enterprise 64bit Symptom: the performance counters related to SQL Server are not displayed in Performance Monitor. Solution: Rebuilding the counters:CD c: \ window

SQL Server's common performance problems can be considered in three aspects: operating system and database configuration, table/index/storage settings, and SQL statements. For delivered systems, it is often difficult to optimize SQL statements due to actual conditions. This article summarizes the practical methods for

Tags: Data Warehouse res warehouse IMA Misc SYS cell nbsp HighlightTo configure the Data collector: 1. Create a login and map roles 2. Configuring the Management Data Warehouse 3. Create collection sets, collection items----msdb data store sp_syscollector_create ... 4. Automatically configure the related job Specific steps: After creating the diagram: To configure Data collection: The refresh looks like this: The method created: Use msdb go declare @collectionsetid int --return val

after you've processed historical data and report data, then add these new hardware, such as faster CPUs and hard drives, larger memory, and so on, but add new hardware postscript to modify your SQL Server configuration to accommodate these new hardware, such as opening/ 3G switch to use more memory. Scale out when scaling the up does isn't suffice or is cost-prohibitive. Use horizontal expansion When yo

,t.text from sys.dm_exec_query_stats as s -information about statements cross apply Sys.dm_ Exec_sql_text (S.sql_handle) as T ORDER by avgtotal Desc --Evaluation of database IO select * from Sys.dm_io_pending_io_requests --Request view of suspend IO select * from Sys.dm_io_ Virtual_file_stats ((Select db_id (' AdventureWorks2014 '), null) --function returns I/O statistics for data and log files- -The description file is suspended Select S.file_id,r.io_pending from sys.dm_io_pend

stress treatment measures, often results will be unsatisfactory. Think like Query OptimizerIn every field there are rules in their domain, and most simply, if you do not conform to the C # specification for programming, such as using keywords incorrectly, then the compilation will be an error. Of course, there will be some hidden rules in each area, and some people will say is the so-called "unspoken rules", such rules are often not materializing, such as you do not meet the best practice to wr

We can use set statistics Io and set statistics time to analyze the performance of T-SQL statements. The method is as follows: In the SQL Server Query analyzer, run: Set statistics profile onset statistics Io onset statistics time ongo -- // The SQL statement to