We have a table that has an identity field along with 5 other domain
fields. The identity field is not declared as a primary key. The
table has 3.5 million records.
A consultant was hired recently to provide insight. His major
recommendation: modify the table to make the identity field a primary
key (i.e., alter table add constraint...)
Is that sound advice? Is it OK to have a table with identity but no
primary keys? What would be the impact on performance?