query tuning in sql server

Label:Paging Query for sqlserver2005 SQLSERVER2005 has been using the top keyword to achieve paged query, but inefficient, in the sqlserver2005 and later versions of the use of row_number () parsing function to complete the paging query, the efficiency has been greatly improved, but the SQL statement is more complex, T

As a small program ape, in the daily development can not avoid to and where in and like to deal with, in most cases we pass the parameters of simple quotes, sensitive word escape directly after the SQL, execute the query, fix. If one day you inevitably need to improve SQL query performance, need a one-time where in hun

Atitit.mysql the use of the Oracle with AS Mode temp table pattern CTE statement to reduce the structural MSSQL SQL for subqueries Server:1. With ... as (...) in the MySQL what should be said in 12. Sub-query and query nesting is mainly easy to improve readability, 23. the solution in MYSQL :: temp table. 24. Seo bla

The company database grows with time, the data is more and more, the query speed is also more and more slow. Into the database to see a bit, hundreds of thousands of of the data, the query is really time-consuming.To improve the query performance of SQL, we generally consider the index as the first consideration. In fa

XML query in SQL Server: For XML specify Auto Objective In SQL Server, an XML query can specify Raw,auto,explicit,path. This article introduces some examples of XML queries that specify auto in

In the previous article, wherein and like implementation of SQL Server parameterized query describes several Implementation Solutions for SQL Server parametric query of wherein. xml and Table value parameters are omitted. Here is

For a slow query, we usually need to know which steps are expensive first, and then try some improvement methods. In general, if you cannot solve the problem by improving the hardware performance or adjusting the OS or SQL server settings, the remaining options are usually the following:1. Add the index of the corresponding field for the "scan" operation.2. Somet

Query optimization on SQL statements. The foreground application works on the database server, and ultimately relies on the SQL statements in the application. According to incomplete statistics, SQL statements consume about 80% of the database server's resources. Therefore,

stored procedure. In particular, do not use nested views. nested views increase the difficulty of searching for original data. Let's look at the nature of the View: it is stored on the server. The optimized SQL query plan has been generated. When retrieving data from a single table, do not use a view pointing to multiple tables. You can retrieve or read the view

Wbk_goods_info where cop_g_no= ' 00078027 'There are only 1 records in the Wbk_goods_info table that meet this condition, and the entire data table has 100,000 records, so the selectivity of this query is 1/100000, which represents very high selectivity, so it is efficient to find data by index. Conversely, or your statement is as follows:Select * from Wbk_goods_info with (index (IDX_COP_G_NO)) where cop_g_no> ' 00018000 'At this time the matching

XML query in SQL SERVER: FOR XML specifies AUTO Preface In SQL SERVER, you can specify RAW, AUTO, EXPLICIT, and PATH for XML queries. This article uses some examples to introduce the XML query of AUTO in

As a little programmer, it is inevitable to deal with where in and like in daily development, in most cases, the parameters we pass are not much simple, single quotation marks, sensitive characters escape, and then directly spelled into the SQL, execute the query, done. If one day you inevitably need to improve the SQL query