GUID nonclustered index
Need a globally unique key for a table, but don’t want to risk performance issues arising from a random clustered index? And you don’t want to deal with similar keys by using newsequentialid?
The solution is to make a clustered index out of a regular identity integer, and use a GUID as a nonclustered primary key:
/* Identity is the clustered index, but not the primary key. Primary key has a non-clustered index. The records are physically inserted in the database in order by the clustered key, but the primary key as a random GUID is still indexed. */ create table dbo.SomeTable ( CX int not null identity ,SomeTableKey uniqueidentifier not null ,... ); go alter table dbo.SomeTable add constraint PK_SomeTable primary key nonclustered (SomeTableKey); go create unique clustered index CIX_SomeTable on dbo.SomeTable (CX); go alter table dbo.SomeTable add constraint DF_SomeTable_Key default (newid()) for SomeTableKey; go