ms sqlserver 索引在MSSQL 2008上试通过，2005需自行测试

对表的CUD操作导致出现不连续行级块出现，也就是传说中的碎片，这时需要对索引重建，也就是把分配的空块干掉。

SELECT OBJECT_NAME(dt.object_id) ,
si.name ,226); color:inherit; line-height:18px"> dt.avg_fragmentation_in_percent,
dt.avg_page_space_used_in_percent
FROM
(SELECT object_id ,226); color:inherit; line-height:18px"> index_id ,226); color:inherit; line-height:18px"> avg_fragmentation_in_percent,226); color:inherit; line-height:18px"> avg_page_space_used_in_percent
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, 'DETAILED')
WHERE index_id <> 0
) AS dt --does not return @R_1_4045@ion about heaps
INNER JOIN sys.indexes si
ON si.object_id = dt.object_id
AND si.index_id = dt.index_id
--------------------------------------------------------------------------------------------
内部碎片和外部碎片

    为了有效的利用内存，使内存产生更少的碎片所以要对内存分页。内存以页单位使用。因为在使用分页装载的过程中经常检查使用的页数也产生的碎片称内部碎片。

为了共享要分段在段的切换过程中形成的碎片称外部碎片。

什么时候该索引重组

    *检查 Externalfragmentation 部分

         o 当avg_fragmentation_in_percent 的值介于 10 到 15 之间

    *检查 Internalfragmentation 部分

         o 当avg_page_space_used_in_percent 的值介于 60 到 75 之间

什么时候该索引重建

    *检查 Externalfragmentation 部分

         o 当avg_fragmentation_in_percent 的值大于 15

    *检查 Internalfragmentation 部分

         o 当avg_page_space_used_in_percent 的值小于 60
建立动态视图。

SELECT 'ALTER INDEX [' + ix.name + '] ON [' + s.name + '].[' + t.name + '] ' +

CASE
WHEN ps.avg_fragmentation_in_percent > 15
THEN 'REBUILD'
ELSE 'REORGANIZE'
END +
WHEN pc.partition_count > 1
THEN ' PARTITION = ' + CAST(ps.partition_number AS nvarchar(MAX))
ELSE ''
END,
avg_fragmentation_in_percent
FROM sys.indexes AS ix
JOIN sys.tables t
ON t.object_id = ix.object_id
JOIN sys.schemas s
ON t.schema_id = s.schema_id
JOIN
(SELECT object_id ,226); color:inherit; line-height:18px"> index_id ,
avg_fragmentation_in_percent,226); color:inherit; line-height:18px"> partition_number
FROM sys.dm_db_index_physical_stats (DB_ID(),128); background-color:inherit">NULL)
) ps
ON t.object_id = ps.object_id
AND ix.index_id = ps.index_id
(SELECT object_id,226); color:inherit; line-height:18px"> index_id ,226); color:inherit; line-height:18px"> COUNT(disTINCT partition_number) AS partition_count
FROM sys.partitions
GROUP BY object_id,226); color:inherit; line-height:18px"> index_id
) pc
ON t.object_id = pc.object_id
AND ix.index_id = pc.index_id
WHERE ps.avg_fragmentation_in_percent > 10
AND ix.name IS NOT NULL
对查询出的建果进行重建
1. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------
2. ALTER INDEX [PK__tb1__3213E83F33139D18] ON [dbo].[tb1] REBUILD PARTITION = 2 50
3. ALTER INDEX [pk_cludered_id_date] ON [dbo].[consume] REBUILD 27.9693855911781
5. (2 行受影响)
6. */

ms sqlserver 索引在MSSQL 2008上试通过，2005需自行测试

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