AW: [UMN_MAPSERVER-USERS] AW: [UMN_MAPSERVER-USERS] slighty OT: new hardware for a mapserver application

[Frank Broniewski]

Thanks alot for all the helpful answers. Though my next question is
(also) somewhat offtopic for the mapserver list, I will ask it anyways
:-)

How do you deal with the relationship of polygons when they are stored
in a postgis-table? E.g. you have several levels of administrative
units. How do you get to the information which smaller level of adm.
unit belongs to the upper level of adm. unit? Right now I use the
classical approach and have ids and parentids and with them I determine
the father and child elements. But when you have postgis, you can do
something like intersect to find all smaller adm. units of a higher
level adm. unit. Which one do you prefer?

I ask, because I have lots of data which have father-child relations
like mentioned above, and so I'm very interested in how other people
handle this.

Greetings from Luxembourg
                                                      
Frank Broniewski
Musée National d'Histoire et d'Art
Section Préhistoire / Projet EPC
    Tél: +352 260 281-21
241, Rue de Luxembourg
L-8077 Bertrange


-----Ursprüngliche Nachricht-----
Von: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] Im
Auftrag von Arnulf Christl
Gesendet: Dienstag, 9. August 2005 18:14
An: MAPSERVER-USERS at LISTS.UMN.EDU
Betreff: Re: [UMN_MAPSERVER-USERS] AW: [UMN_MAPSERVER-USERS] slighty OT:
new hardware for a mapserver application


Frank Broniewski wrote:
> If I may interfere, I have also an question about putting vector data
> into postgis. If I may qoute you:
> 
> 
>>...though i would suggest to
>>merge the shapes and MySQl alpha data into one PostgreSQL/PostGIS
>>feature table. ...
> 
> 
> Are you putting all your e.g. point shapes into one table and seperate
> them by an attribute or do you create one table for one shapefile? Is 
> there an advantage of having all shapefiles of one geometry in one 
> table instead of having one table per shapefile?

Umm, well no special fondness for one or the other. It depends on what 
you plan to do with the data. Being lazy by nature i would probably 
choose one table, gives me less to configure. But in the end it really 
is a question of what you need to do to the data. Is the shape file your

primary source and every time something changes you have to re-import it

(yuck)? Or do you also plan tp maintain the data inside PG?

> I'm curious because here at the museum  we want to put our data also
> into a postgres/postgis db and are unsure about the most clever way to

> accomplish this.
> 
> Your Idea seemed somewhat revolutionary to me, so I wondered if you
> could describe a little more in detail your way of storing shapefiles 
> in the database.

Oh nothing revolutionary, pure laziness and an affection for PG/PostGIS.

You just can do all sorts of cool spatial operations with your data 
simply using SQL once it has been stuffed into PostGIS.

Best, Arnulf.