重组索引vs重建指数在Sql服务器维护计划
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08-06-2019 - |
题
在西南的规则,以更好地SQL服务器数据库是一个示例的完整数据库维护的计划: 西南.在例如它们运行两个重新组织索引,然后重建索引,然后更新的统计数据。有没有点这个吗?我想重新组织索引是一个快但不太有效版本的重建指数?这一指数的重建也将更新的统计数据自动(上聚集指数至少).
解决方案
做一个 REORGANIZE
然后一个 REBUILD
在同一索引是毫无意义的,因为任何改变的 REORGANIZE
将会失去了通过这样做的 REBUILD
.
比这更糟糕的是,在维护计划图从西南,它执行一个 SHRINK
第一,这碎片的索引作为一个副作用的方式释放的空间。那么 REBUILD
分配更多的空间数据库文件再次作工作空间 REBUILD
操作。
REORGANIZE
是一个网上操作,整理叶页在集群或非集群索引页面的网页使用小小的额外工作空间。REBUILD
是一个网上操作的企业的版本,在其他版本,并使用额外工作空间,再次作为索引的大小。它创造了一个新的拷贝的索引,然后下降,从而摆脱分裂。统计数据重新计算作为默认的一部分,这种操作,但可以被禁止。
看看 重组和重建索引 更多的信息。
不要用 SHRINK
除非有 TRUNCATEONLY
选项,即使在那时,如果该文件将再次增长,那么你应该觉得很难,因为是否是必要的:
其他提示
在重组和重建是不同的东西。
重新组织:这是一个整理为索引。需要对现有的索引(es)和整理现有的网页。然而,如果网页都不在一个连续的方式,他们的住宿像以前一样。只有内容的网页正在发生变化。
重建:实际上它下降的索引和重建它从头开始。这意味着你将得到一个完全新的索引,与整理和连续的网页。
此外,与重建可以改变分区或文件的团体,但与重组可以整理,不仅对全体索引,但也只有一个分区指数。
更新的统计数据是自动的,在群集的索引,但是不上的非集群。
之前考虑到维护的指标,重要的是要回答两个主要问题:
- 什么是程度的碎片的?
- 什么是适当的行动?重组或重建?
作为这篇文章中描述 http://solutioncenter.apexsql.com/why-when-and-how-to-rebuild-and-reorganize-sql-server-indexes/, 并帮助你确定是否应该执行指数的重建或重组索引,请理解如下:
指数的重组是一个过程,其中SQL服务器转为通过现有的指标,并清除它。指数的重建是一个重型过程指标是已删除,然后重新从头开始与完全新结构,从所有堆积的碎片和空-空间的网页。
虽然指数的重组是一个纯粹的清理工作的叶子系统的状态,因为它是没有锁定出受影响的表格和视图,重建进程锁的影响表为整个重建时期,这可能导致漫长的下次不能接受的,在某些环境。铭记这一点,清楚的是,该指数的重建是一个进程与更强的'溶液,但是,它带有一个价格可能长时间锁在受影响的索引表。
在另一边,索引外重组是一个'轻'的过程,这将解决碎片在一个较有效的方式–因为清洁指数将永远是第二的新的一个完全从头开始。但是,重新组织索引是更好从效率观点来看,因为它没有锁影响的索引表在课程中的操作。
上述提及的文章还说明了如何重新组织和重建索引使用短程,T-SQL(改组/重建中的索引表)和一个第3方的工具,称为ApexSQL备份。
当做一个重组的一个指数,如果指数是跨越两个或更多的物理文件的数据将只磁盘碎片整理数据的文件。页面是不是从一个数据文件到另一个。
当索引是在一个单一文件的重组和重新编制索引将有同样的最终结果。
一些次重组将以更快的速度,以及某些次重新编制索引将以更快的速度取决于如何碎片的索引。少碎片的索引,然后重组,将更快,更加分散的速度较慢的重组进行,但速度更快一reindex会。
到底是什么 距离 说。这里是我会重新编制索引的整个数据库:
EXEC [sp_MSforeachtable] @command1="RAISERROR('DBCC DBREINDEX(''?'') ...',10,1) WITH NOWAIT DBCC DBREINDEX('?')"
我用这个SP
CREATE PROCEDURE dbo.[IndexRebuild]
AS
DECLARE @TableName NVARCHAR(500);
DECLARE @SQLIndex NVARCHAR(MAX);
DECLARE @RowCount INT;
DECLARE @Counter INT;
DECLARE @IndexAnalysis TABLE
(
AnalysisID INT IDENTITY(1, 1)
NOT NULL
PRIMARY KEY ,
TableName NVARCHAR(500) ,
SQLText NVARCHAR(MAX) ,
IndexDepth INT ,
AvgFragmentationInPercent FLOAT ,
FragmentCount BIGINT ,
AvgFragmentSizeInPages FLOAT ,
PageCount BIGINT
)
BEGIN
INSERT INTO @IndexAnalysis
SELECT [objects].name ,
'ALTER INDEX [' + [indexes].name + '] ON ['
+ [schemas].name + '].[' + [objects].name + '] '
+ ( CASE WHEN ( [dm_db_index_physical_stats].avg_fragmentation_in_percent >= 20
AND [dm_db_index_physical_stats].avg_fragmentation_in_percent < 40
) THEN 'REORGANIZE'
WHEN [dm_db_index_physical_stats].avg_fragmentation_in_percent > = 40
THEN 'REBUILD'
END ) AS zSQL ,
[dm_db_index_physical_stats].index_depth ,
[dm_db_index_physical_stats].avg_fragmentation_in_percent ,
[dm_db_index_physical_stats].fragment_count ,
[dm_db_index_physical_stats].avg_fragment_size_in_pages ,
[dm_db_index_physical_stats].page_count
FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL,
NULL, 'LIMITED') AS [dm_db_index_physical_stats]
INNER JOIN [sys].[objects] AS [objects] ON ( [dm_db_index_physical_stats].[object_id] = [objects].[object_id] )
INNER JOIN [sys].[schemas] AS [schemas] ON ( [objects].[schema_id] = [schemas].[schema_id] )
INNER JOIN [sys].[indexes] AS [indexes] ON ( [dm_db_index_physical_stats].[object_id] = [indexes].[object_id]
AND [dm_db_index_physical_stats].index_id = [indexes].index_id
)
WHERE index_type_desc <> 'HEAP'
AND [dm_db_index_physical_stats].avg_fragmentation_in_percent > 20
END
SELECT @RowCount = COUNT(AnalysisID)
FROM @IndexAnalysis
SET @Counter = 1
WHILE @Counter <= @RowCount
BEGIN
SELECT @SQLIndex = SQLText
FROM @IndexAnalysis
WHERE AnalysisID = @Counter
EXECUTE sp_executesql @SQLIndex
SET @Counter = @Counter + 1
END
GO
并创建一个作业,执行这SP每个星期。
甚至更好的是:
EXEC sp_MSforeachtable 'ALTER INDEX ALL ON ? REINDEX'
或
EXEC sp_MSforeachtable 'ALTER INDEX ALL ON ? REORGANIZE'
我的两个分...这一方法遵循的规范概述了在新技术网: http://technet.microsoft.com/en-us/library/ms189858(v=sql。105).aspx
USE [MyDbName]
GO
SET ANSI_NULLS OFF
GO
SET QUOTED_IDENTIFIER OFF
GO
CREATE PROCEDURE [maintenance].[IndexFragmentationCleanup]
AS
DECLARE @reIndexRequest VARCHAR(1000)
DECLARE reIndexList CURSOR
FOR
SELECT INDEX_PROCESS
FROM (
SELECT CASE
WHEN avg_fragmentation_in_percent BETWEEN 5
AND 30
THEN 'ALTER INDEX [' + i.NAME + '] ON [' + t.NAME + '] REORGANIZE;'
WHEN avg_fragmentation_in_percent > 30
THEN 'ALTER INDEX [' + i.NAME + '] ON [' + t.NAME + '] REBUILD with(ONLINE=ON);'
END AS INDEX_PROCESS
,avg_fragmentation_in_percent
,t.NAME
FROM sys.dm_db_index_physical_stats(NULL, NULL, NULL, NULL, NULL) AS a
INNER JOIN sys.indexes AS i ON a.object_id = i.object_id
AND a.index_id = i.index_id
INNER JOIN sys.tables t ON t.object_id = i.object_id
WHERE i.NAME IS NOT NULL
) PROCESS
WHERE PROCESS.INDEX_PROCESS IS NOT NULL
ORDER BY avg_fragmentation_in_percent DESC
OPEN reIndexList
FETCH NEXT
FROM reIndexList
INTO @reIndexRequest
WHILE @@FETCH_STATUS = 0
BEGIN
BEGIN TRY
PRINT @reIndexRequest;
EXEC (@reIndexRequest);
END TRY
BEGIN CATCH
DECLARE @ErrorMessage NVARCHAR(4000);
DECLARE @ErrorSeverity INT;
DECLARE @ErrorState INT;
SELECT @ErrorMessage = 'UNABLE TO CLEAN UP INDEX WITH: ' + @reIndexRequest + ': MESSAGE GIVEN: ' + ERROR_MESSAGE()
,@ErrorSeverity = 9
,@ErrorState = ERROR_STATE();
END CATCH;
FETCH NEXT
FROM reIndexList
INTO @reIndexRequest
END
CLOSE reIndexList;
DEALLOCATE reIndexList;
RETURN 0
GO
我研究的网络和发现了一些良好的文章。在我写信的功能和脚本,下面这是重新组织、重新创建或重建的所有索引中的数据库。
首先你可能需要读 这篇文章 要了解为什么我们不只是重新创造所有索引。
第二,我们需要一个功能建立创造脚本用的指数。所以 这篇文章 可能会有所帮助。还有我共享工作职能如下。
最后的步骤做的同时,环查找和整理的所有索引的数据库。 这个视频 是篦例做出这一点。
功能:
create function GetIndexCreateScript(
@index_name nvarchar(100)
)
returns nvarchar(max)
as
begin
declare @Return varchar(max)
SELECT @Return = ' CREATE ' +
CASE WHEN I.is_unique = 1 THEN ' UNIQUE ' ELSE '' END +
I.type_desc COLLATE DATABASE_DEFAULT +' INDEX ' +
I.name + ' ON ' +
Schema_name(T.Schema_id)+'.'+T.name + ' ( ' +
KeyColumns + ' ) ' +
ISNULL(' INCLUDE ('+IncludedColumns+' ) ','') +
ISNULL(' WHERE '+I.Filter_definition,'') + ' WITH ( ' +
CASE WHEN I.is_padded = 1 THEN ' PAD_INDEX = ON ' ELSE ' PAD_INDEX = OFF ' END + ',' +
'FILLFACTOR = '+CONVERT(CHAR(5),CASE WHEN I.Fill_factor = 0 THEN 100 ELSE I.Fill_factor END) + ',' +
-- default value
'SORT_IN_TEMPDB = OFF ' + ',' +
CASE WHEN I.ignore_dup_key = 1 THEN ' IGNORE_DUP_KEY = ON ' ELSE ' IGNORE_DUP_KEY = OFF ' END + ',' +
CASE WHEN ST.no_recompute = 0 THEN ' STATISTICS_NORECOMPUTE = OFF ' ELSE ' STATISTICS_NORECOMPUTE = ON ' END + ',' +
-- default value
' DROP_EXISTING = ON ' + ',' +
-- default value
' ONLINE = OFF ' + ',' +
CASE WHEN I.allow_row_locks = 1 THEN ' ALLOW_ROW_LOCKS = ON ' ELSE ' ALLOW_ROW_LOCKS = OFF ' END + ',' +
CASE WHEN I.allow_page_locks = 1 THEN ' ALLOW_PAGE_LOCKS = ON ' ELSE ' ALLOW_PAGE_LOCKS = OFF ' END + ' ) ON [' +
DS.name + ' ] '
FROM sys.indexes I
JOIN sys.tables T ON T.Object_id = I.Object_id
JOIN sys.sysindexes SI ON I.Object_id = SI.id AND I.index_id = SI.indid
JOIN (SELECT * FROM (
SELECT IC2.object_id , IC2.index_id ,
STUFF((SELECT ' , ' + C.name + CASE WHEN MAX(CONVERT(INT,IC1.is_descending_key)) = 1 THEN ' DESC ' ELSE ' ASC ' END
FROM sys.index_columns IC1
JOIN Sys.columns C
ON C.object_id = IC1.object_id
AND C.column_id = IC1.column_id
AND IC1.is_included_column = 0
WHERE IC1.object_id = IC2.object_id
AND IC1.index_id = IC2.index_id
GROUP BY IC1.object_id,C.name,index_id
ORDER BY MAX(IC1.key_ordinal)
FOR XML PATH('')), 1, 2, '') KeyColumns
FROM sys.index_columns IC2
--WHERE IC2.Object_id = object_id('Person.Address') --Comment for all tables
GROUP BY IC2.object_id ,IC2.index_id) tmp3 )tmp4
ON I.object_id = tmp4.object_id AND I.Index_id = tmp4.index_id
JOIN sys.stats ST ON ST.object_id = I.object_id AND ST.stats_id = I.index_id
JOIN sys.data_spaces DS ON I.data_space_id=DS.data_space_id
JOIN sys.filegroups FG ON I.data_space_id=FG.data_space_id
LEFT JOIN (SELECT * FROM (
SELECT IC2.object_id , IC2.index_id ,
STUFF((SELECT ' , ' + C.name
FROM sys.index_columns IC1
JOIN Sys.columns C
ON C.object_id = IC1.object_id
AND C.column_id = IC1.column_id
AND IC1.is_included_column = 1
WHERE IC1.object_id = IC2.object_id
AND IC1.index_id = IC2.index_id
GROUP BY IC1.object_id,C.name,index_id
FOR XML PATH('')), 1, 2, '') IncludedColumns
FROM sys.index_columns IC2
--WHERE IC2.Object_id = object_id('Person.Address') --Comment for all tables
GROUP BY IC2.object_id ,IC2.index_id) tmp1
WHERE IncludedColumns IS NOT NULL ) tmp2
ON tmp2.object_id = I.object_id AND tmp2.index_id = I.index_id
WHERE I.is_primary_key = 0 AND I.is_unique_constraint = 0
AND I.[name] = @index_name
return @Return
end
Sql为,而:
declare @RebuildIndex Table(
IndexId int identity(1,1),
IndexName varchar(100),
TableSchema varchar(50),
TableName varchar(100),
Fragmentation decimal(18,2)
)
insert into @RebuildIndex (IndexName,TableSchema,TableName,Fragmentation)
SELECT
B.[name] as 'IndexName',
Schema_Name(O.[schema_id]) as 'TableSchema',
OBJECT_NAME(A.[object_id]) as 'TableName',
A.[avg_fragmentation_in_percent] Fragmentation
FROM sys.dm_db_index_physical_stats(db_id(),NULL,NULL,NULL,'LIMITED') A
INNER JOIN sys.indexes B ON A.[object_id] = B.[object_id] and A.index_id = B.index_id
INNER JOIN sys.objects O ON O.[object_id] = B.[object_id]
where B.[name] is not null and B.is_primary_key = 0 AND B.is_unique_constraint = 0 and A.[avg_fragmentation_in_percent] >= 5
--select * from @RebuildIndex
declare @begin int = 1
declare @max int
select @max = Max(IndexId) from @RebuildIndex
declare @IndexName varchar(100), @TableSchema varchar(50), @TableName varchar(100) , @Fragmentation decimal(18,2)
while @begin <= @max
begin
Select @IndexName = IndexName from @RebuildIndex where IndexId = @begin
select @TableSchema = TableSchema from @RebuildIndex where IndexId = @begin
select @TableName = TableName from @RebuildIndex where IndexId = @begin
select @Fragmentation = Fragmentation from @RebuildIndex where IndexId = @begin
declare @sql nvarchar(max)
if @Fragmentation < 31
begin
set @sql = 'ALTER INDEX ['+@IndexName+'] ON ['+@TableSchema+'].['+@TableName+'] REORGANIZE WITH ( LOB_COMPACTION = ON )'
print 'Reorganized Index ' + @IndexName + ' for ' + @TableName + ' Fragmentation was ' + convert(nvarchar(18),@Fragmentation)
end
else
begin
set @sql = (select dbo.GetIndexCreateScript(@IndexName))
if(@sql is not null)
begin
print 'Recreated Index ' + @IndexName + ' for ' + @TableName + ' Fragmentation was ' + convert(nvarchar(18),@Fragmentation)
end
else
begin
set @sql = 'ALTER INDEX ['+@IndexName+'] ON ['+@TableSchema+'].['+@TableName+'] REBUILD PARTITION = ALL WITH (ONLINE = ON)'
print 'Rebuilded Index ' + @IndexName + ' for ' + @TableName + ' Fragmentation was ' + convert(nvarchar(18),@Fragmentation)
end
end
execute(@sql)
set @begin = @begin+1
end