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Re: data model help, was Re: Using null date fields to indicate

From: David Fetter <david(at)fetter(dot)org>
To: SF Postgres <sfpug(at)postgresql(dot)org>
Subject: Re: data model help, was Re: Using null date fields to indicate
Date: 2004-08-12 15:21:30
Message-ID: 20040812152130.GG3515@fetter.org (view raw or flat)
Thread:
Lists: sfpug
On Thu, Aug 12, 2004 at 10:39:17AM +0100, Brian Ghidinelli wrote:
> 
> Josh Berkus wrote:
> >How about a SQL dump of just the tables we're dealing with?   I can't 
> >speak 
> 
> These tables don't exist yet, they're in the design stage.

Well, that part's a blessing anyhow.

> >For the sanity of your successors, you may want to consider giving
> >up HU in 
> 
> Since it is intelligible and provides useful information at the
> application development and debugging level, I don't consider it a
> relic.

You seriously missed Josh's point.  What *you* understand is not
relevant from a maintenance point of view.  What your successors are
likely to understand *is*.

> >Now, how does this relate to your question about using NULL dates?
> 
> As asked, I provided examples of how the data is queried and described 
> my current questions:
> 
> 1.  Using NULL dates versus a boolean indicator, for example, in the
> tblMapAttendeeFlags.  The extra information about start and end is
> not really necessary but may be a "nice to have".  My original
> inquiry regarding performance,

You are <a href="http://fetter.org/optimization.html">optimizing</a>.
You are optimizing prematurely.  Stop it now.

> 2. I'm not sure about feeding the PK of tblMapAttendeeClasses from
> to tblMapEventClasses.  The image I sent doesn't have it this way
> but this requirement would force the attendee classes to use those
> classes that have been "offered" explicitly.  I can't decide if
> tblMapEventClasses is completely unnecessary or should be more
> important?
>
> 3. tblMapAttendeeClasses stores 1-n records of a tblLookupAttendee
> record to specify which event parts the attendee participates in
> (along with class, vehicle, instructor, grid pos, etc).  I've
> currently not referenced tblLookupAttendee (uidClubMember, uidEvent)
> but I'm wondering if I'm better off doing so?
> 
> 4. Does my approach for storing arbitrary custom questions (that may
> be of several data types) in tblLookupCustomQ and tblMapCustomQ seem
> OK?  I'm sure others have come across a similar requirement;
> thoughts?

Here's mine.  Hire somebody to help with your design, and take their
advice.  You're in way over your head here.

Cheers,
D
-- 
David Fetter david(at)fetter(dot)org http://fetter.org/
phone: +1 510 893 6100   mobile: +1 415 235 3778

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Next:From: Josh BerkusDate: 2004-08-12 16:49:43
Subject: Re: data model help, was Re: Using null date fields to indicate active/expired records
Previous:From: Brian GhidinelliDate: 2004-08-12 09:39:17
Subject: Re: data model help, was Re: Using null date fields to indicate

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