Re: It's pizza-time again

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Mon, 03 May 2004 18:30:36 +0200
Message-ID: <409673ba$0$562$e4fe514c@news.xs4all.nl>

Dawn M. Wolthuis wrote:

>>x wrote: 
>>mAsterdam wrote: 
>>
>>>This was just an introduction to expand on my uneasy feeling
>>>towards equating 'thing' and 'fact'.
>>>
>>>In that context I also used a distinction:
>>>
>>>_thing_ :
>>>pizza, topping, table, clock, customer, onion, order, order-item.
>>>(now I am not so sure about the last two).
>>>
>>>_fact_ :
>>>"It's 4 p.m", "We are out of onions",
>>>"the customer at table 12 ordered 2 neapolitan icecreams".
>>
>>From these lists I would infer:
>>_thing_ = "material" noun.
>> _fact_ = occured event, occurence
>>
>>Sounds like the distinction between TO BE and TO OCCUR

>
>
> I think of it as a difference between IS (a thing, an entity) and IS TRUE (a
> proposition, predicate). So, when talking about "files" the name and
> description of the file describe the entity and the attributes are
> considered information about that entity -- something that "IS". If we have
> a PERSON entity/file/function, then GENDER is an attribute of that PERSON,
> that entity that IS.

But the "file" would contain many OCURRENCES of PERSON, no? Are we trying to talk about three categories with two concepts?

I mean these:

abstract thing (platonic table, ER.ENTITY SET + attributes, file + fields)
thing (that one overthere, ER.ENTITY, entry)
truth/fact (that table is made of oak, attr value, field value(??) ...)

> In the RM one would talk more about the header for the relationship PERSON
> (some might inaccurately call it a relation) including the attribute GENDER.
> GENDER is part of the predicate associated with PERSON. The values of GENDER
> yield true statements/propositions. It seems to me that the header of the
> RELATIONSHIP provides the metadata for the IS TRUE relationships and the
> notion of an entity is not formally needed nor present. The ENTITY concept
> helps people who are doing data modeling, but from what I have seen, there
> is not need for it in the formal RM.
>

>>>Am I the only one to use this distinction?
>>
>>No. You are not alone. :-)

>
> ditto. --dawn

Sigh of relief :-) Received on Mon May 03 2004 - 11:30:36 CDT