identify poor performance in sql server

A few SQL Server paging stored procedure writing and performance comparisonsStored procedure 5 Kinds of pagination, the following code is from the forgotten when from someone else that CTRL + C, so just as a collection, hope the author see don't Spray me.------Create a Database tutorial data_test-----Create DATABASE Data_testGoUse Data_testGoCREATE TABLE Tb_testt

The impact of using SQL waits blocking on overall performance SQL Server 2000 provides 76 wait types to provide waiting reports. SQL Server 2005 provides an extra 100 wait types to track application

" began, and then check the "suo", and then find the word "rope", according to its page, Turn to the page where the word is located. Of course this requires that 1. All Chinese characters in the Xinhua dictionary are arranged in phonetic alphabet order. 2. The Xinhua dictionary has a phonetic lookup appendix in front of it. Clustered index is also the reason, 1. There is a "phonetic" list of all the data, that is, the index. 2. All data is arranged sequentially on the hard disk according to this

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.[ createddate])=1 Test2, using partitioned view test, cost=136s, with Test1 there is a sign

The first time the data is accessed is much slower than the next access, because it reads the data from the disk and writes it to the buffer; Aggregate queries (Sum,count, etc.) and other queries that scan most tables or indexes require a lot of buffering and can adversely affect performance if it causes SQL Server to discard other data from the cache;

performance of the rapid decline.The original version is actually quite common, and performance is better than after the rewrite (in the case of a very long string). But there is also the problem that if the string is too long, the performance drops sharply.If there is really a string of more than 5W commas. This SQL

SqlServer full-text index performance has never been very good. I heard from my colleagues today and found a skill. I went back and tried it. I found that it can significantly improve the full-text index performance, generally, it can be increased by 2 times + original SQL statement: select * fromTable1whereContants (*, test) optimized

andselectmax(列)(@pageIndexint, --页索引@pageSizeint--页记录数)asbeginsetnocounton;declare @timediff datetimedeclare @sql nvarchar(500)select@timediff=Getdate()set@sql=‘select top ‘+str(@pageSize)+‘ * From tb_TestTable where(ID>(select max(id) From (select top ‘+str(@pageSize*@pageIndex)+‘ id From tb_TestTable order by ID) as TempTable)) order by ID‘execute(@sql)selectd

In earlier articles, the detect methodology in performance tuning was mentioned, and the Detect methodology was briefly reviewed here.Discover the problem: finding problemsExplore The conditions: Reasons to exploreTrack down possible approaches: providing a possible solutionExecute the most likely approach: perform the best possible solutionCheck of Success: Confirm success (if not successful, repeat the above steps)Tie up Loose Ends: complete Remaini

delete all temporary tables at the end of the stored procedure. First truncate the table and then drop the table, so that the system table can be locked for a long time. 25. Avoid using a cursor whenever possible, because the efficiency of the cursor is poor. If the cursor operation has more than 10 thousand rows of data, you should consider rewriting. 26. before using the cursor-based or temporary table method, you should first find a set-based solu

and 3 6. The following query will also cause a full table scan:Select ID from t where name like '% ABC %'To improve efficiency, you can consider full-text search. 7. If a parameter is used in the WHERE clause, a full table scan is performed. Because SQL only parses local variables at run time, but optimizesProgramThe access plan cannot be postponed to runtime; it must be selected during compilation. However, if an access plan is created during com

delete all temporary tables at the end of the stored procedure. First truncate the table and then drop the table, so that the system table can be locked for a long time. 25. Avoid using a cursor whenever possible, because the efficiency of the cursor is poor. If the cursor operation has more than 10 thousand rows of data, you should consider rewriting. 26. before using the cursor-based or temporary table method, you should first find a set-based solu

Tags: ber write amp order parameter IO performance HDD persistence anotherThis article focuses on common metrics for using Performance Monitor to monitor SQL Server under Windows, including the buffer Cache hit Ratio, pages/sec, Available Bytes, Disk Time, AVG. Disk Queue Length, Processor time, Processor queue Length,

The database SQLServer is born with the same parent in the Windows operating system, and they have technical connectivity. This is reflected in many aspects. For example, in our daily work, we can adjust some parameters of the Windows operating system to improve the performance of the SQL Server database server. I. res

SQL Server query performance optimization-index and SARG (I) For non-SARG statements, SQL SERVER must evaluate each record to determine whether it meets the WHERE clause conditions. Therefore, indexes are usually useless for queries using non-SARG conditions. A non-SARG stat

and 3 6. The following query will also cause a full table scan:Select ID from t where name like '% ABC %'To improve efficiency, you can consider full-text search. 7.IfUsing parameters in a clause also results in full table scan. Because SQL only parses local variables at run time, but optimizesProgramThe access plan cannot be postponed to runtime; it must be selected during compilation. HoweverHowever, if an access plan is created during compilat