Thread: postgres and postgis

postgres and postgis

From
Hubert Fröhlich
Date:
Hello,
I have georeferenced entries in a Postgres table, mostly with the
"point", "box" and "polygon" datatypes. I used then for queries from
self-written CGI scripts which works very well.

However, for extending geographical uses of my data, e.g. with
MapServer, I consider switching to PostGIS, which, on the other hand
supports similar datatypes (following OpenGIS Simple Feature
Specifications) , but not the same ones. The advantage of OpenGIS Simple
Features is that lots of popular GIS applications (such as UMN
MapServer) support them.


a) How arere the postgis geometries related with postgresql objects? Is
there a connection in the development?
b) Has anybody tested migrating data from postgres to PostGIS? Is this
step useful? What is the best practice? Or does somebody have an idea
how to provide the connection?


Thanks,

Regards, Hubert

--
-------------------------------------------------------------------------------
Dr.-Ing. Hubert Fröhlich
Bezirksfinanzdirektion München
Alexandrastr. 3, D-80538 München, GERMANY
Tel. :+49 (0)89 / 2190 - 2980
Fax  :+49 (0)89 / 2190 - 2459
hubert.froehlich@bvv.bayern.de


Re: postgres and postgis

From
Hubert Fröhlich
Date:
OK, but there are datatypes (e.g. POINT etc. in Postgres), and I cannot
access them from PostGIS directly, as PostGIS uses similar geometry
types in a *different* way.

How can I use Postgres geometry datatypes in PostGIS directly? Or do I
have to migrate my data (and, eventually, my old apps too) ?


Is there a possibility to unify the development of these different
datatypes?

Regards,

Hubert


P.J. "Josh" Rovero wrote:
> PostGIS *is* postgresql, with added datatypes, operators and functions.
>
> Hubert Fröhlich wrote:
>
>> a) How arere the postgis geometries related with postgresql objects?
>> Is there a connection in the development?
>> b) Has anybody tested migrating data from postgres to PostGIS? Is this
>> step useful? What is the best practice? Or does somebody have an idea
>> how to provide the connection?
>
>
>


--
-------------------------------------------------------------------------------
Dr.-Ing. Hubert Fröhlich
Bezirksfinanzdirektion München
Alexandrastr. 3, D-80538 München, GERMANY
Tel. :+49 (0)89 / 2190 - 2980
Fax  :+49 (0)89 / 2190 - 2459
hubert.froehlich@bvv.bayern.de