韩雨 / 整理SqlServer表上索引碎片
Created 2016-07-25 Modifyed 2016-07-25

306 Words

查询当前数据库的表上索引碎片情况,按照严重程度顺序排列

USE DBNAME;
SELECT 
DB_NAME() AS DatbaseName 
, SCHEMA_NAME(o.Schema_ID) AS SchemaName 
, OBJECT_NAME(s.[object_id]) AS TableName 
, i.name AS IndexName 
, ROUND(s.avg_fragmentation_in_percent,2) AS [Fragmentation %] INTO #TempFragmentation
FROM sys.dm_db_index_physical_stats(db_id(), NULL, NULL, NULL, NULL) s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id] AND s.index_id = i.index_id
INNER JOIN sys.objects o ON i.object_id = O.object_id;

SELECT * FROM #TempFragmentation ORDER BY [Fragmentation %] DESC;

DROP TABLE #TempFragmentation;

查询当前数据库的表上从来没有使用过的索引

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED 
SELECT 
DB_NAME() AS DatbaseName 
, SCHEMA_NAME(O.Schema_ID) AS SchemaName 
, OBJECT_NAME(I.object_id) AS TableName 
, I.name AS IndexName 
INTO #TempNeverUsedIndexes 
FROM sys.indexes I INNER JOIN sys.objects O ON I.object_id = O.object_id


SELECT * FROM #TempNeverUsedIndexes 
ORDER BY DatbaseName, SchemaName, TableName, IndexName


DROP TABLE #TempNeverUsedIndexes

查询当前数据库的表上使用的比较少的索引

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT 
DB_NAME() AS DatabaseName 
, SCHEMA_NAME(o.Schema_ID) AS SchemaName 
, OBJECT_NAME(s.[object_id]) AS TableName 
, i.name AS IndexName 
, s.user_updates 
, s.system_seeks + s.system_scans + s.system_lookups AS [System USAGE] INTO #TempUnusedIndexes
FROM sys.dm_db_index_usage_stats s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id] AND s.index_id = i.index_id
INNER JOIN sys.objects o ON i.object_id = O.object_id ;
SELECT TOP 20 *
FROM #TempUnusedIndexes ORDER BY [user_updates] DESC ;
DROP TABLE #TempUnusedIndexes

重建索引,对于碎片比较厉害的索引,效果比重组要好

ALTER INDEX [INDEX_NAME] ON Table_Name REBUILD PARTITION = ALL WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, ONLINE = OFF, SORT_IN_TEMPDB = OFF )