[postgis-users] Pipeline Data Model

Mon Jan 14 08:38:43 PST 2008

The great part of this data model is the use of linear referencig. does
postgis support linear referencig? or any software that works with it?

im happy to help with all data models you guys are interested in building.
just drop me a line

george

On 1/14/08, Abram Gillespie <abe.gillespie.lists at gmail.com> wrote:
>
> All,
>
> These are all very interesting ideas.  I have a proposal - I've been
> meaning to get a site running at geoloaded.com (nothing there ATM),
> and though sharing data models isn't *specifically* the idea I had in
> mind, it's very much in the spirit of what I intend to do.  I'm happy
> to host anything the group manages to put together.  I'm not clear on
> the EULA of the data model I currently have in my possession, but if I
> can, I will post my results at the site as soon as I have something.
>
> R.B.,
>
> I'm swamped right now but will be in touch as soon as I have a moment.
> I live at 14th & Main BTW.  Small world indeed.
>
> -Abe
>
> On Jan 14, 2008 7:47 AM, Burgholzer,Robert
> <rwburgholzer at deq.virginia.gov> wrote:
> > We might think to do a little divide and conquer strategy on the
> database that Abe has, perhaps recruiting a group of individuals to each
> sign up for a handful of tables to convert to postgres, and then upload them
> all to a sourceforge repository.
> >
> >
> >
> > r.b.
> >
> >
> > -----Original Message-----
> > From:   postgis-users-bounces at postgis.refractions.net on behalf of Chris
> Hermansen
> > Sent:   Sun 1/13/2008 12:47 PM
> > To:     PostGIS Users Discussion
> > Cc:
> > Subject:        Re: [postgis-users] Pipeline Data Model
> >
> >
> > Gustavo makes a great point here.
> >
> > Having worked with workstation ArcInfo for many years, I have a kind of
> > "conceptual library" of how to do common tasks in the field in which I
> work.
> >
> > As I use PostGIS I have to re-learn this "conceptual library", based on
> > the building blocks defined by OGC.  I have to say that my general
> > impression is that the OGC geoprocessing model sometimes necessitates
> > some pretty complicated SQL to achieve what is relatively
> > straightforward in workstation ArcInfo, an example being given in the
> > Wiki on geometrically combining partially overlapping polygon geometries
> > so as not to generate null geometries where only one or the other input
> > geometry exists.
> >
> > In our company, we are (slowly) working on some documentation that
> > demonstrates how to accomplish "model tasks" in PostGIS.
> >
> > One of the biggest challenges we face (and would face on platforms other
> > than PostGIS as well) is cleaning up the cruft coming in from all the
> > nasty shapefiles floating around out there.  For example,
> > self-overlapping polygon geometry, gaps between polygons that aren't
> > supposed to be there, tiny noise components arising from unfiltered
> > GPS-source data.  I could go on :-)
> >
> > Another area of challenges is where we want a different geometric
> > outcome than provided for in the OGC standard.  A simple example is
> > first being surprised by, then dealing with, degenerate geometries or
> > composite geometries generated by what seem to be fairly straightforward
> > geometric operations.  A more complex example is the example given above
> > - most of the time, when we overlay partially overlapping geometries, we
> > don't want null geometries as a result in locations where only one or
> > the other input geometry exists, rather we want whatever geometry exists
> > with the appropriate attributes set to null.
> >
> > Another is creating new geometries from components - geometries from
> > text files, polygons from lines and points, etc.
> >
> > Two things I see discussed on this list that could be of interest in the
> > future are topology and time travel.  Way back when PostgreSQL was just
> > Postgres I did some work with time travel; I can see real potential in
> > the concept, for example as a framework for managing and reporting on
> > environmental certification.  However that's a big design issue even
> > with time travel working :-)  With respect to topology, I'm surprised
> > how little I miss it; though there are people in our offices who find
> > it's the only solution for fixing up really nasty shape files; ie
> > convert the data to coverages and bang away at them using the polygon
> > topology until either nothing is left or the problem is fixed.
> >
> > Anyway.  Whether the approach to sharing this kind of info is through
> > separate projects or just a bit more input to the PostGIS wiki, it seems
> > pretty worthwhile to me.
> >
> > Gustavo Ces wrote:
> > > You can´t export a geodatabase ( i supose your model is just that) by
> > > odbc, because the geometric logic is not transfered ( can you export a
> > > geodatabase in arcgis to postgis?) I think you have to rewrite the
> > > model, adapting it to postgis. Is a hard work, but the you can use the
> > > postgresql full potential ( triggers, views, etc.. ) to make your
> > > model more powerfull, smaller and dynamic.
> > > In my experience, this work simplifies the model, and you can make it
> > > "real-time", user adapted, etc...
> > >
> > > I´ve posted a long time ago a question about postgis models. I imagine
> > > all postgis community members working alone, creating complex
> > > functions and schemas to solve their problems and... reinventing the
> > > wheel. Perhaps it´s time to create especific projects to create ( or
> > > traduce ) schemas and functions for various cases. I know the wiki,
> > > but i think in environmental members creating  schemas, functions to
> > > solve environmental questions( for instance). At this time each of
> > > them has to walk his way alone ...
> > >
> > > It´s just an opinion :)
> > >
> > > Gus
> > >
> > > _______________________________________________
> > > postgis-users mailing list
> > > postgis-users at postgis.refractions.net
> > > http://postgis.refractions.net/mailman/listinfo/postgis-users
> >
> >
> > --
> > Regards,
> >
> > Chris Hermansen · mailto:clh at timberline.ca
> > tel:+1.604.714.2878 · fax:+1.604.733.0631
> > Timberline Natural Resource Group · http://www.timberline.ca
> > 401 · 958 West 8th Avenue · Vancouver BC · Canada · V5Z 1E5
> >
> > C'est ma façon de parler.
> >
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> >
> >
> >
> >
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