用于重建和重新索引碎片索引的脚本？

Question

当'avg_fragmentation_in_percent'超出某些限制时,是否可以提供用于重建和重新索引碎片索引的脚本(如果不使用游标,则更好)？

Answer 1

要重建使用:

ALTER INDEX __NAME_OF_INDEX__ ON __NAME_OF_TABLE__ REBUILD

或重组使用:

ALTER INDEX __NAME_OF_INDEX__ ON __NAME_OF_TABLE__ REORGANIZE

应该在较低(<30%)碎片处使用重组,但只有重建(对数据库较重)才会将碎片降低到0%.
有关详细信息,请参阅https://msdn.microsoft.com/en-us/library/ms189858.aspx

Answer 2

两种解决方案:一种简单,一种更先进.

介绍

根据问题的严重程度,您可以使用两种解决方案

替换为您自己的值,如下所示:

• 替换XXXMYINDEXXXX为索引的名称.
• 替换XXXMYTABLEXXX为表的名称.
• 替换XXXDATABASENAMEXXX为数据库的名称.

解决方案1.索引

在脱机模式下为表重建所有索引

ALTER INDEX ALL ON XXXMYTABLEXXX REBUILD

在脱机模式下为表重建一个指定的索引

ALTER INDEX XXXMYINDEXXXX ON XXXMYTABLEXXX REBUILD

解决方案2.碎片化

碎片是表中经常添加和删除条目的问题.

检查碎片百分比

SELECT  
    ips.[index_id] ,
    idx.[name] ,
    ips.[avg_fragmentation_in_percent]
FROM    
    sys.dm_db_index_physical_stats(DB_ID(N'XXXMYDATABASEXXX'), OBJECT_ID(N'XXXMYTABLEXXX'), NULL, NULL, NULL) AS [ips]
    INNER JOIN sys.indexes AS [idx] ON [ips].[object_id] = [idx].[object_id] AND [ips].[index_id] = [idx].[index_id]

碎片5..30%

如果碎片值大于5%但小于30%,则值得重新组织索引.

重新组织表的所有索引

ALTER INDEX ALL ON XXXMYTABLEXXX REORGANIZE

重组表的一个指定索引

ALTER INDEX XXXMYINDEXXXX ON XXXMYTABLEXXX REORGANIZE

碎片30%+

如果碎片值为30%或更高,则值得重建然后在线模式下的索引.

在表模式下以联机模式重建所有索引

ALTER INDEX ALL ON XXXMYTABLEXXX REBUILD WITH (ONLINE = ON)

在联机模式下为表重建一个指定的索引

ALTER INDEX XXXMYINDEXXXX ON XXXMYTABLEXXX REBUILD WITH (ONLINE = ON)

Answer 3

这是我从http://www.foliotek.com/devblog/sql-server-optimization-with-index-rebuilding中获取的修改过的脚本,我发现这里有用.虽然它使用游标,但我知道游标的主要问题是什么,它可以很容易地转换为无游标版本.

它有详细记录,您可以轻松阅读并根据您的需求进行修改.

  IF OBJECT_ID('tempdb..#work_to_do') IS NOT NULL 
        DROP TABLE tempdb..#work_to_do

BEGIN TRY
--BEGIN TRAN

use yourdbname

-- Ensure a USE  statement has been executed first.

    SET NOCOUNT ON;

    DECLARE @objectid INT;
    DECLARE @indexid INT;
    DECLARE @partitioncount BIGINT;
    DECLARE @schemaname NVARCHAR(130);
    DECLARE @objectname NVARCHAR(130);
    DECLARE @indexname NVARCHAR(130);
    DECLARE @partitionnum BIGINT;
    DECLARE @partitions BIGINT;
    DECLARE @frag FLOAT;
    DECLARE @pagecount INT;
    DECLARE @command NVARCHAR(4000);

    DECLARE @page_count_minimum SMALLINT
    SET @page_count_minimum = 50

    DECLARE @fragmentation_minimum FLOAT
    SET @fragmentation_minimum = 30.0

-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function
-- and convert object and index IDs to names.

    SELECT  object_id AS objectid ,
            index_id AS indexid ,
            partition_number AS partitionnum ,
            avg_fragmentation_in_percent AS frag ,
            page_count AS page_count
    INTO    #work_to_do
    FROM    sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL,
                                           'LIMITED')
    WHERE   avg_fragmentation_in_percent > @fragmentation_minimum
            AND index_id > 0
            AND page_count > @page_count_minimum;

IF CURSOR_STATUS('global', 'partitions') >= -1
BEGIN
 PRINT 'partitions CURSOR DELETED' ;
    CLOSE partitions
    DEALLOCATE partitions
END
-- Declare the cursor for the list of partitions to be processed.
    DECLARE partitions CURSOR LOCAL
    FOR
        SELECT  *
        FROM    #work_to_do;

-- Open the cursor.
    OPEN partitions;

-- Loop through the partitions.
    WHILE ( 1 = 1 )
        BEGIN;
            FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag, @pagecount;

            IF @@FETCH_STATUS < 0
                BREAK;

            SELECT  @objectname = QUOTENAME(o.name) ,
                    @schemaname = QUOTENAME(s.name)
            FROM    sys.objects AS o
                    JOIN sys.schemas AS s ON s.schema_id = o.schema_id
            WHERE   o.object_id = @objectid;

            SELECT  @indexname = QUOTENAME(name)
            FROM    sys.indexes
            WHERE   object_id = @objectid
                    AND index_id = @indexid;

            SELECT  @partitioncount = COUNT(*)
            FROM    sys.partitions
            WHERE   object_id = @objectid
                    AND index_id = @indexid;

            SET @command = N'ALTER INDEX ' + @indexname + N' ON '
                + @schemaname + N'.' + @objectname + N' REBUILD';

            IF @partitioncount > 1
                SET @command = @command + N' PARTITION='
                    + CAST(@partitionnum AS NVARCHAR(10));

            EXEC (@command);
            --print (@command); //uncomment for testing

            PRINT N'Rebuilding index ' + @indexname + ' on table '
                + @objectname;
            PRINT N'  Fragmentation: ' + CAST(@frag AS VARCHAR(15));
            PRINT N'  Page Count:    ' + CAST(@pagecount AS VARCHAR(15));
            PRINT N' ';
        END;

-- Close and deallocate the cursor.
    CLOSE partitions;
    DEALLOCATE partitions;

-- Drop the temporary table.
    DROP TABLE #work_to_do;
--COMMIT TRAN

END TRY
BEGIN CATCH
--ROLLBACK TRAN
    PRINT 'ERROR ENCOUNTERED:' + ERROR_MESSAGE()
END CATCH

Answer 4

2016 年和 2017 年的真正答案是：使用 Ola Hallengren 的脚本：

https://ola.hallengren.com/sql-server-index-and-statistics-maintenance.html

在我们相互进化的这一点上，这就是我们任何人都需要知道或烦恼的事情。

Answer 5

查询REBUILD / REORGANIZE索引

• 30％<=重建
• 5％<=重组
• 5％>什么都不做

查询：

SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName, 
ind.name AS IndexName, indexstats.index_type_desc AS IndexType, 
indexstats.avg_fragmentation_in_percent,
'ALTER INDEX ' + QUOTENAME(ind.name)  + ' ON ' +QUOTENAME(object_name(ind.object_id)) + 
CASE    WHEN indexstats.avg_fragmentation_in_percent>30 THEN ' REBUILD ' 
        WHEN indexstats.avg_fragmentation_in_percent>=5 THEN 'REORGANIZE'
        ELSE NULL END as [SQLQuery]  -- if <5 not required, so no query needed
FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) indexstats 
INNER JOIN sys.indexes ind ON ind.object_id = indexstats.object_id 
    AND ind.index_id = indexstats.index_id 
WHERE 
--indexstats.avg_fragmentation_in_percent , e.g. >10, you can specify any number in percent 
ind.Name is not null 
ORDER BY indexstats.avg_fragmentation_in_percent DESC

输出量

TableName      IndexName            IndexType              avg_fragmentation_in_percent SQLQuery
--------------------------------------------------------------------------------------- ------------------------------------------------------
Table1         PK_Table1            CLUSTERED INDEX        75                           ALTER INDEX [PK_Table1] ON [Table1] REBUILD 
Table1         IX_Table1_col1_col2  NONCLUSTERED INDEX     66,6666666666667             ALTER INDEX [IX_Table1_col1_col2] ON [Table1] REBUILD 
Table2         IX_Table2_           NONCLUSTERED INDEX     10                           ALTER INDEX [IX_Table2_] ON [Table2] REORGANIZE
Table2         IX_Table2_           NONCLUSTERED INDEX     3                            NULL