Re: Relation or attribute and why

On 23 May 2006 10:37:04 -0700, "dawn" <dawnwolthuis_at_gmail.com> wrote:

>Gene Wirchenko wrote:
>> On 23 May 2006 03:41:44 -0700, "Tony Andrews" <andrewst_at_onetel.com>
>> wrote:
>>
>> [snip]
>>
>> >Occam's razor? There is no gain (that I can think of) in separating a
>> >person's name into a separate table Name that has a 1:1 relationship
>> >with the table Person, while there is a cost in terms of complexity.
>>
>> A person's name? Which one? I have two: Eugene Michael
>> Wirchenko and Chen Jin Bai.
>
>Is it a set of names or is there a priority ordering you would give to
>the list. I have seen formerNames as a list-valued attribute (in
>systems which have such), with the ordering being relevant. This is an
>expansion of what many might have as a maidenName attribute.

     It is a set. It has no particular order. Order is practically useless. They are simply the names that I go by.

>In response to Tony, I agree that other than collecting multiple names,
>there is nothing to be gained. So we derive the name and store the
>parts (first, last, middle), whereas with the date, we store the date
>and derive the parts (month, day, year).
>
>What is practice that we used to decide to produce a logical data model
>in this way, sometimes dumping nouns that are collectives from the CDM,
>sometimes dumping the parts, when preparing the LDM?
>
>If the rule of thumb has to do with "the simplest" then is there a
>logical distinction for why deriving the name is simplest in the one
>case and deriving the date parts is simplest in the other or is this
>based on the tools used (having date as a built-in type, but not name,
>for example)? --dawn

     When I was taking my diploma, I wrote a Web site for Chinese. I had family name, given names, and which came first. That is something to take into account when dealing with international names.

     It might not be necessary if the family name is irrelevant, that is, if the name is just an undifferentiated string. This is not too likely, but could happen. We probably want to be able to get "Ms Smith" and "Mr. Chen" out of the data. I thought that also being able get "Jessica Smith" and "Chen Jin Bai" out of the data would be useful.

Sincerely,

Gene Wirchenko Received on Tue May 23 2006 - 21:50:11 CEST