Re: Primary Constraints and Indexes

Wayne,

Yes, you are correct, the second index is unnecessary. Creating the primary key is the same index with the addition of a unique constraint and a not null constraint.

At 07:46 AM 1/10/01 -0800, you wrote:
>As a part-time dba, I am confused about the differences between
>Primary Keys and Indexes.
>
>For example if I create a table "EMPLOYEES" and in the table
>creation statement I do something like:
> create table ...
> constraint XXX primary key (EMP_ID) using index ...
>then later I create an index:
> create index YYY on EMPLOYEE (EMP_ID) ...
>I know I have created two indexes (the first one system-named
>and implicitly created and the second name YYY and created
>explicitly) but do I really need the second index YYY?
>It seems to me the YYY index is not really needed? Can
>someone shed some light on this for me.
>
>THANKS, Wayne
>McGillWL_at_navair.navy.mil
>
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>--
>Author: Wayne McGill
> INET: McGillWL_at_navair.navy.mil
>
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
>--------------------------------------------------------------------
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).
Received on Wed Jan 10 2001 - 11:55:33 CST