我有一张表格,其中有两列的聚集索引——该表的主键。它定义如下:
ALTER TABLE Table ADD CONSTRAINT [PK_Table] PRIMARY KEY CLUSTERED
(
[ColA] ASC,
[ColB] ASC
)WITH (SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF) ON [PRIMARY]
我想要删除这个聚集索引PK,并添加一个如下的聚集索引,使用非聚集索引添加主键约束,也在下面显示。
CREATE CLUSTERED INDEX [IX_Clustered] ON [Table]
(
[ColC] ASC,
[ColA] ASC,
[ColD] ASC,
[ColE] ASC,
[ColF] ASC,
[ColG] ASC
)WITH (PAD_INDEX = ON, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, IGNORE_DUP_KEY = OFF, FILLFACTOR = 90, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = OFF) ON [PRIMARY]
ALTER TABLE Table ADD CONSTRAINT
PK_Table PRIMARY KEY NONCLUSTERED
(
ColA,
ColB
) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
我原本想删除PK聚集索引,然后添加新的聚集索引,再添加非聚集主键索引,但我了解到删除现有的聚集索引会导致表数据重新排序(请参见此处的答案What happens when I drop a clustered primary key in SQL 2005),我认为这不是必要的。该表占用了1TB的空间,因此我真的希望避免任何不必要的重新排序。
我的问题是,从现有结构到期望结构的最佳方法是什么?
编辑:只是想澄清一下。该表占用了1TB的空间,我不幸没有创建临时表的空间。如果有一种不需要创建临时表的方法,请告诉我。