JOINsys.indexes SIWITH(nolock)ONIPS.object_id = SI.object_idANDIPS.index_id = SI.index_id WHEREST.is_ms_shipped = 0 ORDERBY1,5 GO 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 --To Find out fragmentation level of a given database and table --This...
2)此时对sys.dm_db_index_physical_stats进行第一次查询,索引碎片百分比为0: --QUERY INDEX FRAGMENTATION INFO SELECT database_id,object_id,index_id,avg_fragmentation_in_percent,fragment_count,avg_fragment_size_in_pages FROM sys.dm_db_index_physical_stats(DB_ID(),NULL,NULL,NULL,'DETAILED'); 3...
例如,在 SQL Server 2000 中,如果一个表的第 11 页和第 13 页在同一区中,而第 12 页不在该区中,该表不被视为含有碎片。但是访问这些页需要两次物理 I/O 操作,因此,在 SQL Server 2008 中,这将算作碎片。 索引或堆的碎片级别显示在 avg_fragmentation_in_percent 列中。对于堆,此值表示堆的区碎片。...
AND s.avg_fragmentation_in_percent > 5 GROUP BY s.[object_id], s.index_id ) s JOIN sys.indexes i ON s.[object_id] = i.[object_id] AND s.index_id = i.index_id JOIN sys.objects o ON o.[object_id] = s.[object_id] FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)...
https://docs.microsoft.com/en-us/sql/t-sql/database-console-commands/dbcc-showcontig-transact-sql?view=sql-server-ver15 其中, FAST选项指定执行索引的快速扫描,输出结果是最小的,该选项不读索引的叶或数据页且只返回扫描页数、扫描扩展盘区数、扫描密度[最佳值:实际值]、逻辑扫描碎片。TABLERESULTS选项将...
SQL Server index fragmentation is an overarching problem arising from an excessive number of alterations in the database.
從 SQL Server 2016 (13.x) 開始且在 Azure SQL Database 中,REORGANIZE 命令會在線上執行下列額外的重組最佳化: 當已經有 10% 或更多的資料列被邏輯刪除時,系統會實際地將資料列從資料列群組中移除。 舉例來說,如果具有 1 百萬個資料列的已壓縮資料列群組刪除 100,000 個資料列,則...
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 ...
本主題描述如何使用 SQL Server Management Studio 或 Transact-SQL,在 SQL Server 2014 中重新組織或重建片段索引。 每當對基礎資料進行插入、更新或刪除作業時,SQL Server Database Engine 會自動維護索引。 過一段時間後,這些修改就可能使索引中的資訊變成散佈於資料庫中 (片段)。 當根據索引鍵值的邏輯...
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 ...