x schrieb:
> "Alexandr Savinov" <spam_at_conceptoriented.com> wrote in message
> news:43fec3be$1_at_news.fhg.de...
>> dawn schrieb:
>>> I tried to find the latest draft of the cdt glossary, but wasn't sure
>>> if I found the most recent one, so mAsterdam or anyone -- could you
>>> repost the glossary so we can perhaps add in some terms to help with
>>> some of these discussions? We could maybe add dimension, entity, flat,
>>> and a few others.
>>>
>>> For example (just off the top of my head -- these should be improved
>>> upon):
>>>
>>> entity: a thing of interest
>> Although it is an official definition it has the following problems:
>> - it is too general and hence useless
>> - it is equivalent to the term "thing", which is used to refer to anything
>> - entity != dimension, entity != attribute, entity != reference
>>
>> So entity is much more concrete term than simply a thing of interest. I
>> would define it as follows:
>>
>> entity is a thing of interest which has properties, that is, can be
>> characterized by one or more other (primitive or non-primitive)
>> entities, and has an associated identifier.
>>
>> In other words, without an identifier a thing is NOT an entity. Without
>> properties it is also NOT an entity.
>
> Without an identifier a thing is not a thing :-)
It depends how we define a thing. We can assume that a thing may exist
without an identifier or at least without an explicit identifier. I also
can hardly imagine that but we need a kind of catch all term without any
constraints.
> Maybe we can call it "stuff" ?
> Without properties it cannot be identified :-)
It depends how we define a property. I my opinion a property is a
characteristic that is NOT intended to identify entities. Rather it is
intended to describe them semantically (how an entity looks like among
other entities).
thing
/ | \
entity identity dimension
- entity has some identifier
- identifiers refer to some entity
(entities and identities live in pairs)
- dimension can be applied to both entities and identities because both
these things have a structure (fields, columns etc.)
--
http://conceptoriented.com
Received on Fri Feb 24 2006 - 04:19:57 CST
