Sql server clustered index on multiple column with different sort direction

Question

Can I have a clustered index created on multiple columns with different sort direction. For example Create Clustered Index IX_Name on Table1(Empid asc,empname desc,sal asc)

If the answer is yes I am curious to know how, since clustered index store data in one particular order and in the above case we want index to created on three different sort direction.

Thanks in advance

Answer 1

是的，您可以，并且索引的值甚至不需要是唯一的，如果不是，SQL Server 将在每行附加一个行标识符以使其唯一

Answer 2

基于单个唯一键/主键的集群索引，在此基础上制作B-Tree，如果要在多列上使用，我们不能说它是集群索引，它将是非集群索引，因为在非集群索引中我们使用多列。