9i的fundamentals上说重建索引是不需要排序的。但是我只是不知道在move过表以后的重建索引是否需要排序，因为感觉这时索引已经失效了。现在手头上没有什么大表可以测试一下
Index rebuilds have the following characteristics:
? A new index is built using an existing index as the data source.
? Sorts are not needed when an index is built using an existing index, resulting in better
performance.
? The old index is deleted after the new index is built. During the rebuild, sufficient space
is needed to accommodate both the old and the new index in their respective
tablespaces.
? The resulting index does not contain any deleted entries. Therefore, this index uses
space more efficiently.
? Queries can continue to use the existing index while the new index is being built.
