It's strange that you found an non-unique index over a unique column. When you define a unique (or primary key) constraint, Oracle implicitly creates an unique index with the same name of the constraint. The non-unique indexes you found probably were related to another columns (or combination of columns), since it's impossible to have more than one index on the same column.

Just an add, Oracle reccomends that you do NOT create unique indexes explicitly, and let the work to be done automatically. But, if you do it, Oracle will use default settings to the index, what could be a bad thing. So:

1- Create Unique index with particular settings;
2- Create Unique constaints on table.

If you swap these steps, you won't be able to customize your index.


Adriano.