Posted by ZeldorBlat on 10/07/05 06:16

Stefan is right. In most databases, a primary key constraint is the
equivalent of a unique index. The main differences are that you can
only have one primary key constraint per table and the columns involved
cannot allow nulls.

Also many (most) databases also create the primary key index as
clustered -- provided there are no other clustered indexes on the table
(since only one per table is allowed).

[Back to original message]