[postgis-users] What's the Purpose of the Geometry_Columns Table?

[Markus Schaber]

Hi, Strk,

strk at refractions.net wrote:

>> Agreement with Markus.
>>
>> CREATE TABLE thetable ( thegeom GEOMETRY(4326,2,'POLYGON') );
> 
> Also:
> 
> CREATE TABLE thetable ( thegeom ST_POLYGON2D(4326) )
> 
> (this won't need *multi_valued* typmod)

That's right.

Due to the small number of geometry and dimension combinations, we could
possibly implement them using domains over GEOMETRY, but that's not
feasible for the SRIDs.

I don't know yet how DOMAINs affect the type names transmitted in the
client protocol, so it's possible that the jdbc / j2ee / python geotypes
have to be updated, but that might be the case for multi-valued
typemods, too. And, finally, shielding the applications via abstraction
over such changes is the whole point of those projects.

Happy Committing,
Markus
-- 
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

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