[AccessD] question on normalization

Actually, what the machines sort down to is a carrier's route.  The Plus
4 is supposed to get down further than that, but I haven't looked into
it lately, so my knowledge of it is dusty.

Charlotte Foust 

-----Original Message-----
From: Tina Norris Fields [mailto:tinanfields at torchlake.com] 
Sent: Saturday, March 13, 2004 5:45 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] question on normalization


Okay, I just wonder what happened to the original intent of Zip codes - 
wasn't that to uniquely identify delivery locations?  That certainly is 
what I remember - unique codes to make it possible for automatic and 
correct mail sorting by machines.  Hmmmmmmmmmmmm <sits scratching her
head> Tina

Charlotte Foust wrote:

>Unfortunately, while zip codes are supposed to be unique, they may be 
>shared among several small towns or a town may have multiple zip codes.

>Some buildings even have unique zip codes, but generally zip codes 
>belong to post offices.  I would say they were not a good candidate for

>a primary key in dealing with addresses.  I've worked with postal 
>databases and seen some of the "duplicate" zips, where several small 
>towns share a post office and a zip code.  A further complication is 
>the
>+four extension.
>
>Charlotte Foust
>
>-----Original Message-----
>From: John Clark [mailto:John.Clark at niagaracounty.com]
>Sent: Friday, March 12, 2004 7:03 AM
>To: accessd at databaseadvisors.com
>Subject: RE: [AccessD] question on normalization
>
>
>But, in my case, it would be OK then? I will not have an issue with 
>them being unique.
> 
>JW Clark
>
>  
>
>>>>ssharkins at bellsouth.net 3/12/2004 9:55:22 AM >>>
>>>>        
>>>>
>
>
>As a sidebar--sort of--why can't the zip itself be a primary key?
>
>========We're told that ZIP codes aren't unique -- most are, but there 
>those few... I've not encountered it myself, but that's what we're 
>told.
>;) 
>
>Susan H.
>
>  
>

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