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Home -> Community -> Mailing Lists -> Oracle-L -> RE: No Nulls? (was: Warehouse design: snowflake vs star schem
The problem I see with NO NULLS is that artificial data must be created,
where the data is truly not known. Whether you deal with NULLs or artificial
data, you will always have to code accordingly, so it is a wash. Igor's
example is an good one. When I write an app to access the END_EMPLOYMENT
date, I must handle a date of '01/01/4000'. Or I can handle the NULL
condition. As a person who has had to support some very convoluted code, I'd
rather deal with NULL. What if the employee record contained TERM_CODE? I
would rather have the value NULL, meaning they have not been terminated
rather than dealing with hard-coded or lookup values.
-----Original Message-----
Sent: Monday, October 14, 2002 2:14 PM
To: Multiple recipients of list ORACLE-L
END_EMPLOYEMENT date for still employed employees equals to "01/01/4000" (or any other pre-defined date in distant future).
Igor Neyman, OCP DBA
ineyman_at_perceptron.com <mailto:ineyman_at_perceptron.com>
"No application that I can reasonably think of should
use NULLS, except those pre-81
where there are obsolete columns."
Everytime somebody says this to me, I ask them:
How do you handle still employed employees in an EMPLOYEE table that contains a END_EMPLOYEMENT date column?
What's your take?
-----Original Message-----
Sent: Monday, October 14, 2002 2:29 PM
To: Multiple recipients of list ORACLE-L
Jesse,
I'll refrain from personal comments, but on CJ's quote, he's correct.
Nulls
are an oddity. They cannot be true or false (<column_name> = NULL or
<column_name> != NULL), nor can they equal anything. They are in effect a
third
logical state of nothingness. You also have to code most applications with
indicator variables to check for their existence. All in all a real pain in
the
backside. BUT, if you give me the possibility that nulls exist in the data
I
much prefer using them vs. many a third party solution of a single space.
No
application that I can reasonably think of should use NULLS, except those
pre-81
where there are obsolete columns.
Dick Goulet
____________________Reply Separator____________________ Author: "Jesse; Rich" <Rich.Jesse_at_qtiworld.com> Date: 10/14/2002 9:33 AM
On the link below is this quote from C.J.Date:
"I don't want you to think that my SQL solution to your problem means I advocate the use of nulls. Nulls are a disaster."
Of course, he doesn't expound upon it (probably not a need except for dummies like me). Anyone care to comment? (On the quote, not on my dumminess...)
Rich
Rich Jesse System/Database Administrator Rich.Jesse_at_qtiworld.com Quad/Tech International, Sussex, WI USA
> -----Original Message-----
> From: Robson, Peter [ mailto:pgro_at_bgs.ac.uk <mailto:pgro_at_bgs.ac.uk> ]
> Sent: Monday, October 14, 2002 4:59 AM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Warehouse design: snowflake vs star schemas
>
>
> Just for the record (and perhaps to confirm that there are
> always two sides
> to a story). Readers may like to see the article Chris Date
> wrote to Ralph
> Kemball on the subject of business rules and integrity constraints:
>
> http://www.dbdebunk.com/kimball1.htm
<http://www.dbdebunk.com/kimball1.htm>
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com <http://www.orafaq.com> -- Author: Jesse, Rich INET: Rich.Jesse_at_qtiworld.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com <http://www.fatcity.com> San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com <http://www.orafaq.com> -- Author: INET: dgoulet_at_vicr.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com <http://www.fatcity.com> San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Fink, Dan INET: Dan.Fink_at_mdx.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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 Mon Oct 14 2002 - 15:49:09 CDT
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