Re: Recursive join - blind alley?

"Mike Sherrill" <MSherrillnonono_at_compuserve.com> wrote in message news:3gtjvvk4t71etrf73iddsjqsb6qgu5fufi_at_4ax.com...
> On Fri, 2 Jan 2004 08:53:47 -0000, "Mike MacSween"
> <mike.macsween.nospam_at_btinternet.com> wrote:
>
> >This will be an orchestral management system. Musicians and other staff
> >being booked/paid for jobs.
> >
> >A job may contain other jobs, e.g:
> >
> >World Tour contains
> >US leg and Europe leg (and others)
> >US leg contains State tours (and others)
> >New Jersey tour contains Hoboken concert (and others)
> >Hoboken concert contains dress rehearsal, 1st show, 2nd show
>
> I'd just observe that a world tour is probably a tour, not a job.
> Whatever a job is. A tour isn't a leg. A leg isn't a job.

As you aren't sure what a job is then I don't know how you can state that a world tour isn't one.

It's perfectly clear what a job is. It's the name I've applied to an entity type. An instance of which may be related to other instances of the same entity type. This looks like the sort of thing that could be modelled using some sort of hierachical structure. You seem to have other ideas. Perhaps you could let me know what they are.

> >Or a job may be single:
> >
> >My band plays at Simon Foreman's barmitzvah
> >
> >To account for the variability I imagined a recursive join.
>
> What else did you imagine?

What does that mean? I imagined what I said I imagined. A recursive join.

Since then I've found out about materialised paths and nested sets. Nested intervals look useful:

http://dbazine.com/tropashko5.shtml

But I'm afraid my maths isn't up to understanding it fully.

Yours, Mike MacSween Received on Tue Jan 06 2004 - 01:19:46 CET