Re: Impossible Database Design?
Date: Wed, 17 May 2006 00:04:41 GMT
Message-ID: <tMtag.8627$A26.218713_at_ursa-nb00s0.nbnet.nb.ca>
Nikolai Onken wrote:
> Hehe.. thats absolutely true!!
> I probably have not enough experience to really start arguing but I am
> still curious whether there actually is a way to set up a db which
> would
>
> 1. allow infinite events (thats what the client wants or it should at
> least I should make him believe he got it)
Make believe is very easy. Let him specify the open ended-range with '...', and just be aware that that range is actually going to end at some finite time.
> 2. allow the calculation whether ('infinitly') repeating events overlap
> (Is required because I have to see whether a repeating event conflicts
> with another one when adding)
The only way they will NOT overlap is if the period of one is an integral multiple of the other. Otherwise, they are guaranteed to overlap an infinite number of times (assuming eternity).
Think harmonics.
> 3. Not have lots of entries per year (say you have a university with
> 5000 students having 12 lessons 40 weeks a year), and is performant
Define 'lots'.
> 4. (allow exceptions: repeat every monday except monday 15th of May
> 2006)
See the book.
>>Pointing that out usually quiets them down.
>
>
> Pointing out the limits of the computer definitely moves the whole
> issue into perspective - though the problem remains the same and I am
> still curious as to how a workable solution would look like..
See the book.
> It would be quite simple to write a calendar supporting true infinite
> events by just leaving the end date empty but as far as I can think of
> it won't be possible anymore to calculate overlaping events..
You have not been listening. Unless you have an infinite computer, you
cannot create an infinite calendar.
> Anyways I apprechiate your posts and if you have any links or working
> examples I would be more than happy to try them out..
>
> Nikolai
>
Received on Wed May 17 2006 - 02:04:41 CEST