sql server index hint

Tags: function same str indicates GIF selective Sele extended overTransfer from http://blog.csdn.net/single_wolf_wolf/article/details/52915862 I. Understanding the structure of the index Indexes work in databases similar to the role of catalogs in books to improve the speed of finding information. Use an index to find data without scanning the entire table to quickly find the data you need. Microsoft's

I. Non-clustered index maintenanceThe row locator value for a nonclustered index keeps the same clustered index value, even after the clustered index column is physically relocated.To optimize this maintenance overhead, SQL Server

@parent =left (NEWID (), 40)EndInsert Mytesttable (id,parent) VALUES (@id, @parent)Select @[email protected]+1EndGoStep two, do not establish any index query tests/* Query when index is not established */DECLARE @beginTime datetime =getdate ()DECLARE @elapsedSecond int =0SELECT * from mytesttable where parent= ' dd7d9f34-3a9c-43ca-836b-f2babd78ce70 ' and id= ' 103ace5c-7 'Select @elapsedSecond =datediff (m

Summary of index, foreign key, and field syntax maintenance for mysql, SQL Server, and oracle databases, and SQL Server oracle Summary of index, foreign key, and field syntax maintenance for mysql,

Detailed description of SQL Server table and index storage structure, SQL Server This article analyzes in detail the principles of table and index structure storage in SQL

Tags: style blog http io color ar os using SPOriginal: SQL Server index and table architecture (clustered index)Clustered indexOverviewThe concept of index and table architecture has always been the discussion of a lot of topics, including the table of various storage forms

Some people may be confused with primary keys and clustered indexes. In fact, these two concepts are different. The following is a simple description. If you do not want to look at the context text, you can directly look at the comparison between the two. Especially the comparison of the last item. Primary Key) Description from msdn: A table usually has a column or a group of columns that uniquely identify the values of each row in the table. Such a column or multiple columns are called the prim

index is created based on the data that already exists, such as the need to alter INDEX to rebuild the indexes and reset the previously specified filefactor values.When you create an index, if you do not specify Filefactor, the default value of 0 is filled, and the global instance can be configured by sp_configure. Filefactor is also used only on leaf-level pagi

database server;4. The above is the backup and restore of the data, if it is to involve the database structure of the backup, such as table structure, stored procedures ..... Backup, there are two ways: a "Attach" MDF file, which of course will come with all the information, including data, but in the case of MDF, such as the database you want to copy is someone else's server, and your permissions can not

Tags: Sele article results test data sequentially style str default test environmentRecently, some people have asked this question, has not been to delve into the joint index specific use of logic, consult multiple articles, and tested to draw some conclusions Test environment: SQL Server R2 The test results are similar to the MySQL Federated

Joint primary key (joint index) Index Analysis in SQL Server (MySQL) Some people have recently asked this question, but they have not studied the specific use logic of the joint index before. They have read many articles and obtained some conclusions after tests. Test enviro

Tags: itblog custom function ANSI get TCA ORDER by how many ISS goodFirst, the basic concept of indexed viewsAn indexed view is actually a view that "materialized" a set of unique values into a clustered index, which is materialized almost as a table, and its data is stored in one copy (it consumes hard disk space, but the query is fast, for example, you can set count (), sum () in an indexed view). The advantage is that it provides a very quick way t

BuniessDateTime1 between ' 2016-6-21 ' and ' 2016-6-28 'There may be 10,000 data, then BUNIESSDATETIME2,BUNIESSSTATUS1, BUNIESSSTATUS2 filteringFinally, there is only one qualifying piece of data.The difference is that: at the beginning of the filter conditions, determine how many page queries to determine the initial criteria to meet the data, and then further filteringIf the data range that satisfies the query condition is determined relatively accurately at the very beginning, the data that

beginning of the filter conditions, determine how many page queries to determine the initial criteria to meet the data, and then further filteringIf the data range that satisfies the query condition is determined relatively accurately at the very beginning, the data that satisfies the condition can be finally confirmed by a relatively small price.If the data range that satisfies the query condition is determined relatively vaguely at first, the cost of the process is relatively large, although

First, the basic concept of indexed viewsAn indexed view is actually a view that "materialized" a set of unique values into a clustered index, which is materialized almost as a table, and its data is stored in one copy (it consumes hard disk space, but the query is fast, for example, you can set count (), sum () in an indexed view). The advantage is that it provides a very quick way to find the information behind the view. After the first