SQL Server index fragmentation is an overarching problem arising from an excessive number of alterations in the database. Definition Related Products Related Resources What is Index Fragmentation in SQL Server?
To find any database fragmentation you can run the various Disk Usage reports in the database right click in SSMS. Alternatively, you can use various SQL Server management views and functions. For example: select S.name as [Schema], O.name as [Object], I.name as [Index], round(P.avg...
For more information, see the section Index with included columns in this guide. An xml data type can only be a key column only in an XML index. For more information, see XML indexes (SQL Server). SQL Server 2012 SP1 introduced a new type of XML index known as a Selective XML Ind...
SELECT@IndexName='index_name'--enter name of index SET@ID=OBJECT_ID('table_name')--enter name of table --Get the Index Values SELECT@IndexID=IndID FROMsysindexes WHEREid=@IDANDname=@IndexName --Display the fragmentation DBCCSHOWCONTIG(@id,@IndexID) 对于小于100数据页,重建索引并不会有明显...
--Get the Index Values SELECT@IndexID=IndID FROMsysindexes WHEREid=@IDANDname=@IndexName --Display the fragmentation DBCCSHOWCONTIG(@id,@IndexID) 对于小于100数据页,重建索引并不会有明显的性能改善。这是因为物理硬件缓存,SQL Server缓存和SQL Server预读机制隐藏了碎片的负面作用。但对于非常大的表,重建...
Modifies an existing table or view index (rowstore, columnstore, or XML) by disabling, rebuilding, or reorganizing the index; or by setting options on the index. Transact-SQL syntax conventions Syntax Syntax for SQL Server, Azure SQL Database, and Azure SQL Managed Instance. syntaxsql Copy ...
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Analytics Platform System (PDW) SQL database in Microsoft Fabric This article helps you decide when and how to perform index maintenance. It covers concepts such as index fragmentation and page density, and their impact on ...
Modifies an existing table or view index (rowstore, columnstore, or XML) by disabling, rebuilding, or reorganizing the index; or by setting options on the index. Transact-SQL syntax conventions Syntax Syntax for SQL Server, Azure SQL Database, and Azure SQL Managed Instance. syntaxsql Copy ...
This causes index fragmentation and can slow the performance of queries that search a range of the index. To eliminate the fragmentation, consider rebuilding the indexes on the file after shrinking. Unless you have a specific requirement, don't set the AUTO_SHRINK database option to ON. ...
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance SQL database in Microsoft Fabric When you perform online index operations, the following guidelines apply: Clustered indexes must be created, rebuilt, or droppe...