Re: C constraints

From: Steve Bell <swayne.bell_at_sympatico.ca>
Date: Mon, 26 Mar 2001 12:48:18 GMT
Message-ID: <3ABF3802.525D501E@sympatico.ca>

Hi,

It means that there are no Primary Keys, Foreign Keys or Unique constraints. Your data has no referential integrity. There could be a myriad of performance implications especially if you're working with more than one table at a time ..caretesian products, full table scans, to name just a couple. The "C" constraints you're seeing are probably just NOT NULL columns (which is a form of check constaint).
Create the other appropriate constraints mentioned above.

Regards,
Steve

Dudo wrote:

> The CONSTRAINT_TYPE column in USER_CONSTRAINTS has only one value for all
> the tables:
> "C"
> No P or U or R ...
> What does it mean for performance?
> If it isn't easy to explain, can you suggest any article on subject?
>
> Thanks
Received on Mon Mar 26 2001 - 06:48:18 CST