---- Set a non-primary key to clustered index [Step 4] to: http://king123654789.iteye.com/blog/1169191
1. View All indexes. Clustered indexes are created on the primary key by default.
Sp_helpindex person
2. -- delete the primary key constraint and remove the index constraint on the primary key queried in [1], for example, PK _ person _ 117F9D94. Remove the primary key constraint from the primary key field. This field is not the primary key.
Alter table person drop constraint PK _ person _ 117F9D94
3. -- create a clustered index to another column
Create clustered index test_index on person (date)
4.-If the original primary key field is changed to the primary key field, a non-clustered index is automatically created because the clustered index is already in place]
Alter table person add primary key (id)
SQL Server Index Structure and usage (I) SQL Server Index Structure and usage (ii) SQL Server Index Structure and usage (iii) SQL Server Index Structure and usage (IV)