Relational Database Without Relations

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » Article Discussions » Article Discussions by Author » Discuss Content Posted by Eugene Bereznuk » Relational Database Without Relations

14 posts, Page 2 of 2

««1 2

Relational Database Without Relations

Rate Topic

Display Mode

Topic Options

Author

Message

Steve Jones - SSC Editor

Posted Monday, August 05, 2002 9:48 AM

SSC-Dedicated

Group: Administrators
Last Login: 2 days ago @ 1:47 PM
Points: 31,406, Visits: 13,722

Didn't get through the white paper, but did look at 3 of their sample apps. All look the same. Not sure there's anything great here.

Steve Jones
sjones@sqlservercentral.com
http://www.sqlservercentral.com/columnists/sjones

Follow me on Twitter: @way0utwest

Forum Etiquette: How to post data/code on a forum to get the best help

Post #37581

tonyisyourpal

Posted Wednesday, August 21, 2002 10:27 AM

Forum Newbie

Group: General Forum Members
Last Login: Thursday, August 22, 2002 12:00 AM
Points: 2, Visits: 1

Dear oh dear !

I always worry when the phrase "I just want to..." turns up, I really do. Reminds me of "I don't want to learn to drive, I just want to get in a car and go places" !

Perhaps the "whacky schemas" referred to earlier occur because those designing the schemas don't really understand the relational model properly, and instead of viewing a database as a collection of predicates & facts lapse into programmerese and think of a database as a collection of records in files !

It's been said before in the replies above, but a visit to http://www.dbdebunk.com can only help (although it can get a little heated at times...)

- Tony

In a world without walls or fences, what need have we of Windows or Gates ?

In a world without walls or fences, what need have we of Windows or Gates ?

Post #37583

tonyisyourpal

Posted Wednesday, August 21, 2002 10:34 AM

Forum Newbie

Group: General Forum Members
Last Login: Thursday, August 22, 2002 12:00 AM
Points: 2, Visits: 1

And also ...

In response to Andrew C-S, who said that EF Codd's "abstract mathematical concept [of a relation] corresponds closely to the table in modern databases" ... well, sadly, it doesn't. Relations can't have duplicates (for two reasons; relations are sets, and sets can't have duplicates; and relations form assertions of fact, so it's pointless asserting the same fact twice in the absence of "fuzzy" or weighted logics). Also, as originally defined, relations don't allow null.

SQL tables both allow duplicates and allow nulls, so strictly aren't relations (although if you're sensible, you'll always design your tables to prevent duplicates, and avoid using null because of tri-value logic horrors).

- Tony

In a world without walls or fences, what need have we of Windows or Gates ?

In a world without walls or fences, what need have we of Windows or Gates ?

Post #37584

Andrew Sturt

Posted Monday, May 09, 2005 9:28 AM

Forum Newbie

Group: General Forum Members
Last Login: Monday, October 29, 2007 3:23 PM
Points: 5, Visits: 2

A small note to the author: Relational databases are so called, not because the tables relate to each other, but because the data within any given table is all related. As my source for this tidbit of information, I quote Paul Nielson, author of the "Microsoft SQL Server 2000 Bible."

Andj

Post #180878

« Prev Topic | Next Topic »

14 posts, Page 2 of 2

««1 2

Permissions