identify poor performance in sql server

, because the amount of data is small, designers and testers often only notice the implementation of the function, and rarely notice the lack of performance, until the system put into actual operation for some time, only to find that the performance of the system is decreasing, At this time to consider the improvement of system performance will cost more human an

-consuming to index the above, so the efficiency is lower than using the self-increment field.3, CombGiven the pros and cons of the two primary key types above, the comb type can be used to find a balance for both. Its design idea is this: since the GUID type has no regularity can be made index inefficient, affecting the performance of the system, then can not be combined to preserve the GUID of the first 10 bytes, with the latter 6 bytes to represent

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,

Long time no article, before the system officially launched, the DBA will generally test the performance of the serverFor example you have a lot of servers, some do Web server, some do cache server, some do file server, some do database serverThe server to do the database

Label:Reprint Link: http://www.cnblogs.com/knowledgesea/p/3683505.htmlOverview of ToolsIf you have a database application system, there are a large number of tables, views, indexes, triggers, functions, stored procedures, SQL statements, and so on, and the performance of the poor, and the bitter you have to optimize it, then what should you do? Brother teaches yo

Label:Original: SQL Server performance Tuning (i)--judging system resource bottleneck from waiting stateView the status of all SQL Server tasks at that time (sleeping, runnable, or running) through the DMV2005, 2008 provides the following three view Tudon detailed query:

Original: Set STATISTICS io and set STATISTICS time in SQL Server query performance optimizationIn recent times, has been exploring the SQL Server query performance issues, of course, also aimless search for a lot of information,

, and the virtual memory counters are two main: Paging file:% usage to monitor the usage ratio of Paging File instances Process:paging File Bytes to monitor the size of virtual memory The more data stored in virtual memory, the greater the gap between the amount of physical memory and the actual demand, the ratio% Usage is only as a reference value, and if the long time is close to 100%, then the system is likely to be abnormal. Second, monitor

not produce a large number of duplicate values, you can consider the sentence to be opened. The open clause should contain an index. 9, SET showplan_all>10, careful use of cursors In some situations where cursors must be used, consider moving the qualifying data rows into a temporary table, and then defining the cursor for the temporary table, which can improve performance significantly. Note: The so-called optimization is where the clause takes a

Foreword: This article is to blog http://www.dbnewsfeed.com/2012/09/08/5-performance-killers-when-working-with-linked-servers/ Translation, if the translation is not good or bad place, please point out, we study progress together. Respect the original and translated labor results, please indicate the source when reproduced. Thank you!When using a linked server (Linked Servers), the most expensive cost is th

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

Label:Currently in a project optimization, want to analyze SQL Server system performance through the database layer, check the online code, modify the title and DMVs code, the following code can be used to analyze the system after a period of time, those statements are system busy SQL statement. As a reference. Alterna

milliseconds. --2.sql Server Analysis and compile time: CPU time = 0 milliseconds, elapsed time = 0 milliseconds. (35292 rows affected)--3. Table ' SalesOrderDetail '. Scan count 1, logical read 337 times, physical read 4 times, read 333 times, LOB logic read 0 times, lob physical read 0 times, lob read 0 times. --4. SQL