学步园

/* =================================================================================  

OrchidCat     http://blog.csdn.net/OrchidCat

2011-07-05

   在日常的使用中,数据库管理员将会经常性的针对索引进行监控及相应的处理.
   针对此应用,现将常用的几个关于索引状况的T-SQL列出,希望对正在使用MS SQL Server的朋友所有帮助.

=========================================================================  */

--1.  查找当前数据库中索引对应的表名,列名以及类型信息

--All Index

SELECT OBJECT_SCHEMA_NAME(T.[object_id],DB_ID()) AS [架构],  
  T.[name] AS [表名], I.[name] AS [索引名], AC.[name] AS [列名],  
  I.[type_desc] AS [索引类型]
FROM sys.[tables] AS T  
  INNER JOIN sys.[indexes] I ON T.[object_id] = I.[object_id]  
  INNER JOIN sys.[index_columns] IC ON I.[object_id] = IC.[object_id] 
  INNER JOIN sys.[all_columns] AC ON T.[object_id] = AC.[object_id] AND IC.[column_id] = AC.[column_id] 
WHERE T.[is_ms_shipped] = 0 AND I.[type_desc] <> 'HEAP' 
ORDER BY T.[name], I.[index_id], IC.[key_ordinal]

--2.  查找当前数据库中索引的碎片信息

--Fragmentation

SELECT object_name(IPS.object_id) AS [表名], 
   SI.name AS [索引名称], 
   IPS.Index_type_desc AS [类型], 
   IPS.avg_fragmentation_in_percent, 
   IPS.avg_fragment_size_in_pages, 
   IPS.avg_page_space_used_in_percent, 
   IPS.record_count AS [行数], 
   IPS.ghost_record_count AS [幻影记录行数],
   IPS.fragment_count, 
   IPS.avg_fragment_size_in_pages
FROM sys.dm_db_index_physical_stats(db_id(DB_NAME()), NULL, NULL, NULL , 'DETAILED') IPS
   JOIN sys.tables T WITH (nolock) ON IPS.object_id = T.object_id
   JOIN sys.indexes SI WITH (nolock) ON IPS.object_id = SI.object_id AND IPS.index_id = SI.index_id
WHERE T.is_ms_shipped = 0
order by IPS.avg_fragment_size_in_pages desc

--生成满足条件重建索引的T-SQL

DECLARE 	@页满度		TINYINT = 80   --可修改
DECLARE 	@索引页总数	TINYINT = 80   --可修改

SELECT  'alter index ' + i.name + ' on ' + OBJECT_NAME(i.id) + ' rebuild'
FROM    Manufacture.sys.sysindexes i ,
        Manufacture.sys.dm_db_index_physical_stats(DB_ID('希望查找的数据库名称'), NULL,
                                                   NULL, NULL, 'SAMPLED') o
WHERE   i.id = o.object_id
        AND i.indid = o.index_id
        AND o.page_count > @索引页总数
        AND avg_page_space_used_in_percent < @页满度
        AND i.name NOT LIKE '_WA%'

--3. 查找当前数据库中依照成本计算,应补充的索引

--missing index

SELECT  
[表名]=sys.objects.name, 
[累计平均成本]=(avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) ,
[T_SQL]='CREATE NONCLUSTERED INDEX ix_IndexName ON ' + sys.objects.name COLLATE DATABASE_DEFAULT + ' ( ' + IsNull(mid.equality_columns, '') + CASE WHEN mid.inequality_columns IS NULL 
                THEN ''  
    ELSE CASE WHEN mid.equality_columns IS NULL 
                    THEN ''  
        ELSE ',' END + mid.inequality_columns END + ' ) ' + CASE WHEN mid.included_columns IS NULL 
                THEN ''  
    ELSE 'INCLUDE (' + mid.included_columns + ')' END + ';', 
[相等谓词列]=mid.equality_columns, 
[不等谓词列]=mid.inequality_columns, 
[查询涵盖列]=mid.included_columns 
FROM sys.dm_db_missing_index_group_stats AS migs 
        INNER JOIN sys.dm_db_missing_index_groups AS mig ON migs.group_handle = mig.index_group_handle 
        INNER JOIN sys.dm_db_missing_index_details AS mid ON mig.index_handle = mid.index_handle AND mid.database_id = DB_ID() 
        INNER JOIN sys.objects WITH (nolock) ON mid.OBJECT_ID = sys.objects.OBJECT_ID 
WHERE     (migs.group_handle IN 
    ( 
    SELECT     TOP (500) group_handle 
        FROM          sys.dm_db_missing_index_group_stats WITH (nolock) 
        ORDER BY (avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) DESC))  
    AND OBJECTPROPERTY(sys.objects.OBJECT_ID, 'isusertable')=1 
ORDER BY [表名] asc

--4. 查找未使用的索引

--Unused

SELECT 
[表名]=o.name, 
[索引名称]=i.name, 
[索引ID]=i.index_id, 
[读次数]=user_seeks + user_scans + user_lookups   
, [写次数] =  user_updates   
, [行数] = (SELECT SUM(p.rows) FROM sys.partitions p WHERE p.index_id = s.index_id AND s.object_id = p.object_id)
, CASE
	WHEN s.user_updates < 1 THEN 100
	ELSE 1.00 * (s.user_seeks + s.user_scans + s.user_lookups) / s.user_updates
  END AS [读写比]
, 'DROP INDEX ' + QUOTENAME(i.name) 
+ ' ON ' + QUOTENAME(c.name) + '.' + QUOTENAME(OBJECT_NAME(s.object_id)) as 'T_SQL'
FROM sys.dm_db_index_usage_stats s  
INNER JOIN sys.indexes i ON i.index_id = s.index_id AND s.object_id = i.object_id   
INNER JOIN sys.objects o on s.object_id = o.object_id
INNER JOIN sys.schemas c on o.schema_id = c.schema_id
WHERE OBJECTPROPERTY(s.object_id,'IsUserTable') = 1
AND s.database_id = DB_ID()   
AND i.type_desc = 'nonclustered'
AND i.is_primary_key = 0
AND i.is_unique_constraint = 0
AND (SELECT SUM(p.rows) FROM sys.partitions p WHERE p.index_id = s.index_id AND s.object_id = p.object_id) > 10000
ORDER BY 读次数