索引碎片整理的四种方法:
1)删除索引并重建
2)使用 DROP_EXISTING 语句重建索引
3)使用 ALTER INDEX REBUILD 语句重建索引
4)使用 ALTER INDEX REORGANIZE 重新组织索引
--1.查看碎片
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 %] ,
CASE WHEN avg_fragmentation_in_percent > 30 THEN ‘严重碎片,索引需要重建‘
WHEN avg_fragmentation_in_percent >= 5
AND avg_fragmentation_in_percent < 30 THEN ‘轻度碎片,索引需要重新组织‘
ELSE ‘正常状态‘
END 提示
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
ORDER BY [Fragmentation %] DESC
--2.整理碎片(建议在空闲时间运行,尤其不要在生产环境运行)
SET NOCOUNT ON
DECLARE @Objectid INT ,
@Indexid INT ,
@schemaname VARCHAR(100) ,
@tablename VARCHAR(300) ,
@ixname VARCHAR(500) ,
@avg_fip FLOAT ,
@command VARCHAR(4000)
DECLARE IX_Cursor CURSOR
FOR
SELECT A.object_id ,
A.index_id ,
QUOTENAME(SS.NAME) AS schemaname ,
QUOTENAME(OBJECT_NAME(B.object_id, B.database_id)) AS tablename ,
QUOTENAME(A.name) AS ixname ,
B.avg_fragmentation_in_percent AS avg_fip
FROM sys.indexes A
INNER JOIN sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL,
NULL, ‘LIMITED‘) AS B ON A.object_id = B.object_id
AND A.index_id = B.index_id
INNER JOIN SYS.OBJECTS OS ON A.object_id = OS.object_id
INNER JOIN sys.schemas SS ON OS.schema_id = SS.schema_id
WHERE B.avg_fragmentation_in_percent > 10
AND B.page_count > 20
AND A.index_id > 0
AND A.IS_DISABLED <> 1
--AND OS.name=‘book‘
ORDER BY avg_fip DESC ,
tablename ,
ixname
OPEN IX_Cursor
FETCH NEXT FROM IX_Cursor INTO @Objectid, @Indexid, @schemaname, @tablename,
@ixname, @avg_fip
WHILE @@FETCH_STATUS = 0
BEGIN
--碎片率>5%或<=30%,索引重组
IF @avg_fip < 30.0
SET @command = N‘ALTER INDEX ‘ + @ixname + N‘ ON ‘ + @schemaname
+ N‘.‘ + @tablename + N‘ REORGANIZE ‘;
--碎片率>=30%,索引重建
IF @avg_fip >= 30.0
AND @Indexid = 1
BEGIN
IF EXISTS ( SELECT *
FROM SYS.columns
WHERE OBJECT_ID = @Objectid
AND max_length IN ( -1, 16 ) )
SET @command = N‘ALTER INDEX ‘ + @ixname + N‘ ON ‘
+ @schemaname + N‘.‘ + @tablename + N‘ REBUILD ‘;
ELSE
SET @command = N‘ALTER INDEX ‘ + @ixname + N‘ ON ‘
+ @schemaname + N‘.‘ + @tablename + N‘ REBUILD ‘
+ N‘ WITH (ONLINE = ON)‘;
END
IF @avg_fip >= 30.0
AND @Indexid > 1
BEGIN
IF EXISTS ( SELECT *
FROM SYS.index_columns IC
INNER JOIN SYS.columns CS ON CS.OBJECT_ID = IC.OBJECT_ID
AND CS.column_id = IC.column_id
WHERE IC.OBJECT_ID = @Objectid
AND IC.index_id = @Indexid
AND CS.max_length IN ( -1, 16 ) )
SET @command = N‘ALTER INDEX ‘ + @ixname + N‘ ON ‘
+ @schemaname + N‘.‘ + @tablename + N‘ REBUILD ‘;
ELSE
SET @command = N‘ALTER INDEX ‘ + @ixname + N‘ ON ‘
+ @schemaname + N‘.‘ + @tablename + N‘ REBUILD ‘
+ N‘ WITH (ONLINE = ON)‘;
END
--打印命令,单独执行
PRINT @command
--直接执行命令
--EXEC(@command)
FETCH NEXT FROM IX_Cursor INTO @Objectid, @Indexid, @schemaname,@tablename, @ixname, @avg_fip
END
CLOSE IX_Cursor
DEALLOCATE IX_Cursor