Re: Constraints and Functional Dependencies

mAsterdam <mAsterdam_at_vrijdag.org> wrote:

>paul c wrote:
>> mAsterdam wrote:
>>> ...
>>> A rephrase to (i) could be:
>>>
>>> <reference>
>>> (i a)
>>> A relation R with attribute a (written as R(a)) having
>>> a as a reference into S(b)
>>> is expressed as follows:
>>>
>>> forall R(a): exists S(b): a = b
>>>
>>> Note that b need not be a ck to S, hence 'into', not 'to'.
>>> </reference>
>>>
>>>
>>> But what exactly is the reference referencing?
>>
>> I'm sure there is a term for that kind of English phrasing. For myself,
>> the phrase "reference referencing" seems unnecessarily ornamental.
>
>Ornamental? I am a non-native speaker of English - maybe a
>native speaker (you are, aren't you?) can put into less words
>than this what I mean with it.
>
>How would you say: "The stuff referenced is not a tuple in S,
>but a subset of S".

     "What is referred to is not a tuple in S, but a subset of S."

     I am confused by it though. Do you mean "What is referred to is a subset of S." (emphasis on set) or "What is referred to is a tuple in a subset of S." (subset definition not specified)?

>> In ordinary English, one relation references another.

                                     ^^^^^^^^^^
     "refers to".

>One relation may reference several others.
>What do you call the individual referencing attribute sets?

     I do not know.

>What do you call the stuff being referenced?

     "referee" is possible, but probably "target" or "object".

[snip]

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:

     I have preferences.
     You have biases.
     He/She has prejudices.