sql server varchar max performance

Yesterday's SQL Server query performance optimization-index creation principle (I) mainly introduced the principle. today are some of the main principles and checks the created indexes. Iii. indexing principles In general, building indexes depends on the data usage scenarios. In other words, which SQL statements are co

This article is an example of SQL Server 2005 solution to the maximum data type problem. Things started very simply. Megaware's marketing department wants a new Web site to publish documents, and the development team feels that using a SQL Server 2000 database as a document storage repository makes things ea

Label:Poptest is the only training institute for developing Test and development engineers in China, aiming at the ability of the trainees to be competent in automated testing, performance testing and testing tools development. In Poptest's LoadRunner training, in order to improve the performance of students experience, add a lot of server optimization knowledge,

improve the performance. DECLARE @Query VARCHAR(100)SET @Query = 'SELECT * FROM Sales.Customers WHERE contactname = @contactname'EXECUTE sp_executesql @Query,N'@contactname VARCHAR(50)',@contactname = 'Allen, Michael' TRY-CATCH for Exception Handling After SQL Server 2005,

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

Original http://www.cnblogs.com/BoyceYang/archive/2013/06/15/3138142.html Read navigation 1. Overview 2.RulesLogic Database Design 3.EnableDesign with efficient Indexes 4.EnableEfficient Query Design 5.EnableLow performance analysis with technology 6. Summary 1. Overview This is the most effective way to optimize SQL server

Sometimes, all you do to make the application run faster WorkMake some minor adjustments here or there. But the key lies in determining how to adjust it! Sooner or later, you will encounter this situation: SQLThe query cannot respond as you want. It either does not return data or takes a surprising amount of time. If it reduces the speed of enterprise applications, users must wait for a long time. Users want their applications to respond quickly and their reports can return analysis data instant

constraints; to ensure that each inserted, updated, or deleted record meets the constraints, SQL Server needs to consider whether to add constraints to a table with a large amount of data.VarcharVARCHAR is a common type of database, but it may also lead to unexpected performance overhead. Every time we store variable-length columns,

not think of its impactThis parameter is a data-level option that can be set up to refer to　　What is the automatic parameterization of the case?In a simple parameterized mode, SQL Server automatically parameterize a adhoc SQL statement with only one execution mode, thus achieving the purpose of reusing the execution plan.What types of

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

SQL Server Performance Tuning methodology and common tools, SQL Server Tuning In earlier articles, we mentioned the DETECT methodology in Performance Tuning. Here we will briefly review the DETECT methodology. Discover the proble

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

are in order.Then, when SQL Server is doing all of these things, it creates locks to ensure that users get meaningful results. SQL Server guarantees that when each statement is executed, the database is fully predictable (for example, predicting how SQL executes) and managi

not think of its impactThis parameter is a data-level option that can be set up to refer to　　What is the automatic parameterization of the case?In a simple parameterized mode, SQL Server automatically parameterize a adhoc SQL statement with only one execution mode, thus achieving the purpose of reusing the execution plan.What types of

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

OrderDate,OrderID FROM ordDemoWHERE OrderDate='2011-11-28 20:29:00.000'GOAfter observing the execution plan, you will find that the query is parsed to index scan instead of the previous index seek? This is because the two indexes we have created do not contain the OrderId field. Delete the non-clustered Index and re-create it (the OrderId field is also used as the Index field) CREATE NONCLUSTERED INDEX idx_orderdate_orderIdon ordDemo(orderdate DESC,OrderId ASC)GOExecute the query again. The e

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

SQL Server Full-text indexing performance has been not too good, listen to colleagues today to share, found a skill, go back to try, found that can obviously improve the performance of full-text indexing, generally can improve twice times + Original SQL statement: SELECT