Thinking about a dive site "schema"

[Dirk Hohndel]

On Thu, Jan 29, 2015 at 06:04:26PM +0100, Henrik Brautaset Aronsen wrote:
> On 29 Jan 2015, at 17:49, Dirk Hohndel <dirk at hohndel.org> wrote:
> > 
> > Our "Location" text becomes the key for a dive site data base. How this
> > key into this data base is structured is primarily up to the user. We
> > will not enforce any schema on this.
> 
> Or maybe just a numeric ID?  That way we don't have to update all dives whenever we edit the name.  But I guess that's not too much of a hassle anyway.

I find numeric IDs extremely unintuitive.
So yes, Turtle Reef can be many dive sites. As can be Blue Hole. But
together with a region it should be reasonably unique

> > Let's ignore this and say that we switched into "dive site mode". Every
> > dive site has a number of items associated with it.
> > 
> > GPS coordinates
> > Site name (= (part of) our location string?)
> > Description
> > Local notes
> 
> What's the difference between Description and Local notes?  I suggest just having one Notes field.

I explained that elsewhere. One is the description that comes from / is
shared with the web service, the other are your personal notes.

E.g.:

Name: Yellow House
Description: Dive park across the street from the yellow house. Access via
a set of stairs. Access restricted and only available by permission,
contact owner at xxx-xxx-xxxx
Local notes: Key to locker 34-12-44

> > The first two are mandatory. If you don't have a name and GPS coordinates,
> > you don't have an entry in this data base.
> 
> I disagree to this.  It has happened to me many times that I add a site
> and some notes and a picture, but I add the GPS coordinates later.  It
> would be a pain (at least for me) to have that coordinate requirement.
> And what would we do when importing a lot of dives and sites from
> another software, and there are no GPS coordinates?  Do we drop the site
> descriptions? 

Hmm. I see your point. Uploading them to a web site without GPS data makes
no sense, but for your own local data GPS indeed should be optional.

>  So I suggest that just the name is mandatory.
> 
> > Based on what some website do, we could add more items, but I'm not sure I
> > want to do that; feedback welcome:
> > 
> > Currents
> > Hazards
> > Water type
> > Marinelife
> > Maxdepth
> > Mindepth
> 
> I'm not sure I like these at all, at least not before there is a
> definite request for it.   Most of those variables could be fetched as
> statistics from the related dives, and I think it's a good idea not to
> over-engineer this from the start.

Well, Mindepth and Maxdepth are about the site, right? Mindepth would be
the shallowest part of the reef - so on some dive sites that may be 20m;
if you don't want to go that deep this is just a blue water dive, so don't
go there. Maxdepth is the deepest part of the bottom. E.g. there's a sandy
bottom at 18m, reef goes up to 3m. Don't go there if you are teaching a
trimix class.

Water type is kinda obvious and useful :-)

The other, yeah, I don't know. They come from one of the web sites I'm
talking to, to be honest.

> So, lot's of good stuff here.  But it's a good idea to start simple, I think.

Agreed. But I also don't want to oversimplify things so that we have
issues taking advantage of what's out there...

/D