Re: Is Primary Key always the index of the table in Oracle?

From: Jaap W. van Dijk <j.w.vandijk.removethis_at_hetnet.nl>
Date: Wed, 07 Mar 2007 08:13:57 GMT
Message-ID: <45ee7275.869093@news.hetnet.nl>

On 6 Mar 2007 08:00:39 -0800, "fitzjarrell_at_cox.net" <fitzjarrell_at_cox.net> wrote:

...
>
>Actually what you can do is use a non-unique index for a primary key
>constraint. You cannot have a primary key constraint without an
>index.
>
>
>David Fitzjarrell
>

...
Yes you can (you cannnot do DML on the tabel then though). This has its use in a datawarehouse when a table only changes during load. When loading:

remove the constraint
load the table
create the constraint without the index (DISABLE VALIDATE)

The last step is quicker than with an index, and you spare the space of the index.

Jaap. Received on Wed Mar 07 2007 - 02:13:57 CST