index performance tuning in sql server

SQL Server Performance Tuning entry (graphic version) Step 1: capture sample data during business peaks(About 2 hours ). The tool used is the profiler that comes with sqlserver, also known as the event probe. For example, after entering, click the button on the leftmost side to create a new trail: DBO permission is required for logon, therefore, you can log on wi

Server CountersThe Access Methods object in SQL Server provides a counter that monitors access to logical data in the database, and the Buffer Manager counter monitors physical access to the database on disk. Access Methods access Mode Access methods monitors the methods used to access data stored in the database to help determine whether you can improve query

Tags: performance optimization for SQL Server administrator-required skillsPerformance optimizations for SQL Server administrator-required skillsSQL Server is one of the essential services of the enterprise, so it is a great chall

columns are frequently accessed at the same time, and each column contains duplicate values. You can consider creating a composite index;③ Composite indexes should try to overwrite key queries, and the leading column must be the most frequently used column.2. is null and IS NOT NULLNull cannot be used as an index. Any column containing null values will not be included in the index. Even if there are multiple columns in the index, as long as one of these columns contains null, this column will b

) include (Gender,createtime) You can see that we have modified the index after using include Gender,createtime, the index Ix_username has reached the full coverage of all the columns of the datasheet users, at which point there is no doubt that Query 2, query 3 does not appear bookmark lookup, The bookmark lookup for query 4 also disappears. At this point the index ix_username structure is as follows Index Ix_username has reached the full coverage of the users table, for our qu

are: not,! =, 10. Use Delete sparinglyIn general, some of the logic of deleting data will be implemented more or less in stored procedures. For a small number of tables, the problem is not very big. But for large data tables, deleting data with delete can have a certain effect on the performance of the stored procedure. Because delete takes a full table-by-scan approach, it is a transactional operation that is counted into the

;, ②. Multiple columns are frequently accessed at the same time, and each column contains duplicate values. You can consider creating a composite index; ③ Composite indexes should try to overwrite key queries, and the leading column must be the most frequently used column. 2. is null and IS NOT NULL Null cannot be used as an index. Any column containing null values will not be included in the index. Even if there are multiple columns in the index, as long as one of these columns contains null, t

the mass query as little as possible with the format conversion. 5, when in SQL SERVER 2000 If the stored procedure has only one parameter and is of the output type, the parameter must be given an initial value when the stored procedure is invoked, otherwise a call error will occur. 6. Order BY and Gropu by Using the order by and group by phrases, any index contributes to the

SQL Server Performance Optimization (1) Database Design Can you refer to the recent forum on the emergence of an excellent post http://topic.csdn.net/u/20100415/10/a377d835-acbd-4815-8bcb-b367f88ac8b5.html? 92227Database design includes physical design and logical design:Physical DesignYou can use the raid hardware architecture.To put it simply, the usage policy

, and query 4, the query can only be completed by indexing IX_UserName, without the need to perform a bookmarked search. Now let's take a look at the overhead and query plan of these two queries. We can see that we do not need to prompt the index. The query optimizer has automatically selected our index, logical reads also dropped to 2 times Users UserName Users ((IX_UserName)) UserName For more information about Include, see the include charm in

(IX_UserName)) where UserName like 'ja%' For more information about Include, see the include charm in SQL Server indexes (indexes with contained columns) It is explained that the bookmarked search has a great impact on the query performance and is basically inevitable. This does not mean that the bookmarked search is a great beast. We didn't know what a bookmar