rebuild index sql server

The traditional relational database service engine is often not the best platform for analyzing and computing ultra-large amounts of data, so SQL Server has developed an analytics service engine to analyze and calculate large amounts of data. Of course, for the data storage platform SQL Server database engine, there is

SQL Server insert efficiency (heap table vs clustered index table) "Which of the following is more efficient for SQL Server insert operations in heap tables or clustered index tables? Why is it high ?" Some colleagues have aske

clustered index makes the data in the table orderly based on the key-value contact. Deciding which key value to use as a clustered key is an important factor, and when traversing to the leaf level, you can get the data itself rather than simply getting a pointer to the data (nonclustered index data is not overwritten). The clustered index has a row in the Sys.pa

, SQL Server uses three methods to implement this grouping, and the first one requires your assistance: Happy to find data series that have been pre-categorized by the component group. by executing a set of data Hash operation. Sorts the order in which the data is grouped. Pre-classificationThe index of the pre-categorized data is your way,

The following is an example of SQL Server full-text index. For more information about how to create a full-text index using the system stored procedure, see: 1) Start the full-text processing function of the database (sp_fulltext_database) 2) create a full-text directory (sp_fulltext_catalog) 3) register in the full-te

the cache execution plan on the Hot Standby Database Server (I originally wanted to capture the SQL and found that some SQL statements are really not supported, and there is no possibility of automatic resolution ), then, together with the execution times of the execution, that is, the statistical information of the table, it is down to the data table of a backu

Http://www.cnblogs.com/gaizai/archive/2010/01/11/1644358.html Before I start, I want to talk about several concepts. Overwrite Query] When an index contains all the columns referenced by a query, it is usually called "Overwrite query ". [Index coverage] If the returned data column is included in the index's key value, or included in the index's key value + clustered index's key value, no bookup lookup occ

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

Today, I investigated a defect in the project and found that SQL Server sorts the guid column andClusterSpecial processing of index. Two knowledge points are involved. One is how SQL Server sorts guid columns.AlgorithmImplementation. The second is the difference between clus

completes, it The effect on the system is permanent 3, the syntax for creating the transaction:--Start transaction--BEGIN TRANSACTION--Define variables, accumulate errors during transaction execution--DECLARE @erro rsum int Set @errorSum = 0--initialized to 0, that is, no error--adding and deleting operations---set @errorSum = @errorSum [Emailprotect ED] @error--Cumulative error ...--determine if the transaction was committed or revoked based on an error--if (@errorSum =0) Commit Transactio N--

@num intSet @num = 1;WhileBeginIf @num%2=0BeginPrint @numEndSet @num [Email protected]+1EndThings: The ability to guarantee a large number of operations in a batch, if there is a failure, you can return to the original state. Ensure that the operation is correct.Only if the data changes, it will trigger things, that is, to increase the deletion.Classification:Explicit transactions (manual write required)Implicit transaction (MSSQL Default, no manual required)Begin tryBEGIN Tran-Set the point of

being filled, wait 30 seconds and check again waitfor Delay ' ' End 2: Use the corresponding statement to filter the columns with full-text indexes. The specific statement is as follows: Select * from [mydb]. [DBO]. [users] Where contains (loginname,'"Ad *"')--Obtain the select record containing ad in The nvarchar field loginname* From [mydb]. [DBO]. [sites] Where contains (properties,'"Haha"')-Obtain records containing Haha in the XML field properties. 3: Because

accelerate the connection between tables and tables.◊ When you use grouping and sort clauses for data queries, you can significantly reduce the time to group and sort in queries.Disadvantages of the index:◊ It takes time to create indexes and maintain indexes, and increases the amount of time that is consumed as the volume of data increases.◊ indexes require disk space, and each index occupies a certain am

Sort index fragments to improve the speed of SQL Server. For details, refer. Sort index fragments to speed up SQL Server. For details, refer. Database Table A has 100,000 records, and the query speed is normal. However, after imp

I am going to index the fields of a table in SQL server2005 today. The creation fails. Check the table structure. The original field is nvarchar (max) and cannot be indexed. Later, change this field to nvarchar (4000) and re-execute the create statement. The following prompt is displayed: Warning! The maximum key length is 900 bytes. The index 'ix _ project_labe

Let's take a simple look at how the SQL Server Index works. We will not talk about the index concepts. Clustered index: (Figure) Let's look at figure A, the structure of the clustered index. The data page is the place where the d

Label:written in front of the crap : The index problem has been a cliché, although it is often said, but as I have not used the index (very scary bar), I as a MS-BI implementation engineer incredibly useless index, speak naturally not emboldened. Prior to the understanding of the index to stay in the "know" point of vi