Re: primary key

From: John P. Higgins <jh33378_at_deere.com>
Date: Wed, 25 Nov 1998 15:43:15 -0600
Message-ID: <365C79F3.67774CC2@deere.com>

Why have a 'constant' in a primary key? The 'real' primary key is the second column. It must be unique in and of itself. A check constrain is cheaper than a column in a primary key.

Why even have it in the table?

Frank Leenders wrote:

Hello all,

due to our development tool we will have a table with a primary key
consisting of two columns and the first column containing always the same
value. Will this influence the efficiency of the optimizer or influence the
statistics in a bad way? Will the index be build in an inefficient way?

Thanx

Frank

  Received on Wed Nov 25 1998 - 15:43:15 CST