Re: Primary Keys

From: Bob Blizard <rblizard_at_bb.cmcsys.com>
Date: 1995/04/14
Message-ID: <3mml1a$nsp_at_caesar.ultra.net>#1/1

pconnors_at_BIX.com (pconnors on BIX) wrote:

>DPWCC02.OBERLE02_at_SSW.ALCOA.COM (Oberle, John F.) writes:
 

>>Can someone tell me the significance of the primary key
>>constraint. What are the advantages or disadvantages over
>>creating unique indexes.
 

>>Thanks in advance;
 

>>John F. Oberle

>They are pretty much the same under the hood.
 

>The primary key constraint creates a unique index, but it
>uses a system-generated name and defaults the storage and
>tablespace. For that reason, our shop is putting a standard
>in place that constraints are to have the index name
>and storage info created explicitly.

The same can be said for unique indexes, so far as the storage part goes. It is always a good idea (read mandatory) to specify both name and storage. Don't forget tablespace, either! How many people have had the problem of would-be DBAs creating users with no default tablespace, and then wondering why SYSTEM always needed to be extended?
Bob Blizard rblizard_at_bb.cmcsys.com | All these worthwhile

CMC Systems, Inc.                      | opinions are mine, and

175 Littleton Rd Westford, MA 01886 | not necessarily CMC's... Ph (508) 392-1300 Fax (508) 392-1303 | "If you want to park in the first row of life, you must go there first." Received on Fri Apr 14 1995 - 00:00:00 CEST