server index

SQL Server Index Structure and usage (4)Author: freedk I. An in-depth understanding of the index structureIi. Improve SQL statementsIii. General paging display and storage process for small data volumes and massive data Importance of clustered index

SQL Server Index Structure and usage (4)Author: freedk I. An in-depth understanding of the index structureIi. Improve SQL statementsIii. General paging display and storage process for small data volumes and massive data Importance of clustered index

SQL Server Index Structure and usage (2)Author: freedk I. An in-depth understanding of the index structure Improve SQL statements Many people do not know how SQL statements are executed in SQL server. They are worried that the SQL statements they

There are a couple of concepts to talk about before you start."Overwrite Query"When an index contains all the columns referenced by a query, it is often referred to as an "overwrite query.""Index Overlay"If the returned data column is contained in

--Create a clustered indexCreate Table [dbo].[pub_stocktest] Add constraint [pk_pub_stocktest] Primary Key Clustered ([Sid] ASC) with(Pad_index= off, Statistics_norecompute= off, sort_in_tempdb= off, Ignore_dup_key= off,Online= off, Allow_row_locks=

through David Durante , 2011/10/05the seriesThis article is part of the stair series: Ladder index for SQL ServerThe basis of the index database design tells the developer to use the intent of the Database Designer. Unfortunately, the index is often

1. Operations that produce fragmentationBy Sys.dm_index_physical_stats, pages on the index are fragmented when they are not contiguous, and fragmentation is the physical result of page splits on the index.(1). Insert operation:Insert operations can

--Judging useless index: SELECT TOP db_name () as DatabaseName, ' [' + schema_name (o.schema_id) + '] ' + '. ' + ' + object_name (s.[object_id]) + '] ' as TableName, i.name as IndexName, I.type as Indextype, S.user_updates, S.system_seeks +

This article is "Stairway Series:Part of the ladder for SQL Server indexingIndexes are the basis of database design and tell developers to use the database with regard to the designer's intentions. Unfortunately, when performance problems arise,

I. OverviewWhen it comes to b-tree organization, it refers to the index, which provides a quick access to the data. Indexes make the data organized in a specific way, making the query operation the best performance. As the data table becomes larger,

The concept of an indexThe purpose of the index: our data query and processing speed has become a measure of the success of the application system standards, and the use of indexes to speed up data processing speed is often the most commonly used

The concept of an indexThe purpose of the index: our data query and processing speed has become a measure of the success of the application system standards, and the use of indexes to speed up data processing speed is often the most commonly used

OriginalThe concept of an indexPurpose of the IndexOur data query and processing speed has become a measure of the success of the application system standards, and the use of indexes to speed up data processing speed is often the most commonly used

first, the concept of bookmark searchBookmarks can help SQL Server quickly direct from the nonclustered index entry to the corresponding line, but I can actually say a few words about it.　　If the table has a clustered index (the section structure),

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

Step One: Query Index fragmentation, the script is as follows, the library is relatively large when the execution time is very long, although the database has little impact, it is recommended to perform during off-peak hours. ( Select the database

This index cannot be designed from the design view of the data (or it may not be found!). ）[SQL]View PlainCopy CREATE INDEX ix_contractdetail_quantity On Contractdetail (Costid, substatus, Note) INCLUDE (Quantity); And the only

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,

In a database with a large number of transactions, tables and indexes are fragmented over time. Therefore, to improve performance, you should periodically check the fragmentation of tables and indexes, and defragment them with a lot of fragmentation.

WorkaroundMethod 1, rebuild the specified index, this method has no performance to talk about. The table is not yet accessible at rebuild time.Method 2, rebuild the index online, only supported by SQL Server Enterprise Edition.Method 3, using fill