Re: Difference between UNIQUE constraint vs index

"Brandon Aiken" <BAiken@winemantech.com> writes:
> SQLite, MySQL, and MS Access each use indexes for unique constraints.
> Doesn't the SQL spec specify that CREATE INDEX can be used to create
> UNIQUE indexes?

No, there is no such command in the SQL spec.  In fact the concept of an
index does not appear anywhere in the spec ... it's an implementation
detail.

            regards, tom lane