-- Find the average fragmentation percentage of all indexes -- in the HumanResources.Employee table. SELECT a.index_id, name, avg_fragmentation_in_percent FROM sys.dm_db_index_physical_stats (DB_ID(N'AdventureWorks2012'), OBJECT_ID(N'HumanResources.Employee'), NULL, NULL, NULL)...
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_fragmentation_in_percent, 1) as [Percentage Out-of-Order],round(100.0 - P.avg_page_space_used_in_percent, 1) [...
To ensure that the index fragmentation percentage level of a SQL Server instance is fresh and updated, head over to theFragmentationtab and from theAnalyzedrop-down menu choose one of the two presented analysis. The scan analysis will be performed, and its results are shown in the index grid ...
avg_fragmentation_in_percent Logical fragmentation (out-of-order pages in the index). avg_page_space_used_in_percent Average page density. For compressed row groups in columnstore indexes, fragmentation is defined as the ratio of deleted rows to total rows, expressed as a percentage. sys.dm_db...
Data moved to shrink a file can be scattered to any available location in the file. 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. ...
This value is 100 if everything is contiguous; if this value is less than 100, some fragmentation exists. BestCount The ideal number of extent changes if everything is contiguously linked. ActualCount The actual number of extent changes. LogicalFragmentation Percentage of out-of-order pages ...
如果使用SQL Server 2008或更高版本,可以使用活动监视器查找最近执行的昂贵查询。在SSMS中,右击数据库服务器,选择Activity Monitor。 可以通过使用DMV dm_exec_query_stats可以获取更多的信息。当查询优化器为查询创建执行计划时,它会缓存计划进行重用。每次使用查询计划执行查询时,性能统计会被保留。可以使用dm_exec_que...
Syntax for SQL Server, Azure SQL Database, and Azure SQL Managed Instance.syntaxsql Copy ALTER INDEX { index_name | ALL } ON { REBUILD { [ PARTITION = ALL [ WITH ( <rebuild_index_option> [ , ...n ] ) ] ] | [ PARTITION = partition_number [ WITH ( <single_partition_rebuild_...
Extent fragmentation This is the percentage of out-of-order extents in the leaf pages of a heap. An out-of-order extent is one for which the extent that contains the current page for a heap isn't physically the next extent after the extent that contains the previous page. ...
Percentage of pages found in the buffer cache without having to read from disk. The ratio is the total number of cache hits divided by the total number of cache lookups since Microsoft SQL Server was started. After a long period of time, the ratio does not change very much. Because readin...