[postgis-users] Re: Proposed SQL interface for PGRaster

[Patrick]

"Stephen Marshall" <smarshall at wsi.com> wrote in message 
news:4575E64E.3020108 at wsi.com...
> Mark,
>
> I agree that the user needs to know about the endian-ness of the data. 
> However, I'm envisioning a system where the data is returned in a 
> well-known image format, e.g. Geo-TIFF, JPEG2000, etc.

Hi Stephen,

I am very much against serving up the data in any specific format. PGRaster 
*is* the format. I would say that PostGIS serves up the data in some 
generic, described format, just plain ol' tiles AFAIAC, and that client side 
applications convert this to a format the user is requesting.

There are a number of reasons to do this. First of all, most GIS 
applications don't work with file-based formats; the first thing they do is 
convert it to some internal representation. Secondly, the user or 
application can potentially request a HUGE slab of data and thus cripple the 
server.

My contention is that if PostGIS supports rasters and does so well, then 
applications will implement a driver to access the data in PostGIS format. 
The same happened with the standard geometries now in PostGIS. I don't think 
any application accessing PostGIS does so by converting WKT to a shapefile 
and then read in the shapefile.

Cheers,
Patrick