Re: unique contraint without index

Taral wrote:
> Yes, you can create unique constraint on this two column and will not
> create unique index
>
> ALTER TABLE table_name
> add CONSTRAINT constraint_name UNIQUE (column1, column2, ... column_n);
>
>
> On Jan 16, 12:07 pm, "oracle dba" <aoracle..._at_gmail.com> wrote:
> > hi all,
> > In my database I don't want any index on three columns (a,b and c) I
> > need unique contraint on three columns, so that value will not repeat.
> > Is it possible.
> > And if no, then unique key is better or primary key for space usage
> > prospective. Or if YES then pls tell me how.

That only avoids a *unique* index, The OP wanted to avoid having any index at all, which is not possible.

Regarding the space usage, unique and non-unique indexes use exactly the same amount of space.

I suppose making it an index-organized table would save space, though bear in mind that these are not good for bulk loads because you can't mark the index unusable, and IIRC there are some partition exchange operations they don't support. Of course these may not be an issue here. Received on Tue Jan 16 2007 - 04:18:12 CST