primary and unique index

Posted in 1999

samir BADAOUI — Wed, 29 Sep 1999 08:26:01 PDT — source: Informix-list mailing list archive (1991-1998)

hi all, in my database, I have a primary key with columns (a,b,c) and a unique index with columns (a,b,c). I think that the primary key is enough and i can drop the unique key. Wath do you think ??. i can't drop the primaru key because it serves in the references constraints. thanks for help. ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

↪ replying to samir BADAOUI

Art S. Kagel — Wed, 29 Sep 1999 15:51:09 -0400 — source: Informix-list mailing list archive (1991-1998)

Yes the primary key constraint and unique constraint are mutually redundant, indeed the second of these that you added to the table is sharing the index created by the other. Also the FOREIGN KEY constraint references cn use either the unique or primary key constraints. Art S. Kagel samir BADAOUI wrote: > > hi all, > in my database, I have a primary key with columns (a,b,c) and a unique index > with columns (a,b,c). I think that the primary key is enough and i can drop > the unique key. Wath do you think ??. > i can't drop the primaru key because it serves in the references > constraints. > > thanks for help. > > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com