[postgis-devel] Typmod Again

[Paragon Corporation]

No we don't

POINTZ, POLYGONZ POLYGONZM, POINTZM  ->  just POINT, POLYGON  -- so we have
POINT(1 2 3), POINT(1 2 3 4)

Technically I believe we are in violation of the standards here.  So Paul's
proposal -- while a breaking change would be more compliant. 

-----Original Message-----
From: postgis-devel-bounces at postgis.refractions.net
[mailto:postgis-devel-bounces at postgis.refractions.net] On Behalf Of Chris
Hodgson
Sent: Wednesday, July 22, 2009 5:25 PM
To: PostGIS Development Discussion
Subject: Re: [postgis-devel] Typmod Again

According to the 1.4 manual, postgis has the following type options:

The type of the spatial object. To restrict the spatial column to a single
type, use one of: POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING,
MULTIPOLYGON, GEOMETRYCOLLECTION or corresponding XYM versions POINTM,
LINESTRINGM, POLYGONM, MULTIPOINTM, MULTILINESTRINGM, MULTIPOLYGONM,
GEOMETRYCOLLECTIONM. For heterogeneous (mixed-type) collections, you can use
"GEOMETRY" as the type.

I don't see any Z options, let alone GEOMETRYZ/M. Do we really have
different types for each possible type and 2/3/4-d combination?

Chris

Paul Ramsey wrote:
> OK, working into the typmod implementation, I found this interesting
quirk.
> Before, I was talking about
>
> geometry(srid, type, dims)
>
> But, in fact, dims is implicit in type, and you probably want that.
> IE, 'POINTZM' (as defined in Table 4 of SFSQL 1.2.0) is a valid type, 
> and implies a dimensionality of four. We want our types to include 
> that information so we can distinguish between POINTM and POINTZ, 
> otherwise, we could define geometry(4326, POINT, 3) and be able to 
> accept both POINTM and POINTZ.
>
> So that brings us down to just
>
> geometry(srid, type)
>
> Anything I'm missing?
>
> P
> _______________________________________________
> postgis-devel mailing list
> postgis-devel at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-devel
>   

_______________________________________________
postgis-devel mailing list
postgis-devel at postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-devel