Database interface for GRASS

[Malcolm Williamson]

On Sat, 13 Apr 1996, Eric Buddington wrote:

> 
> I've been pondering the multitude of data formats and coordinate systems
> available, and the difficulty of transformation from one to the other. In
> writing programs that convert to GRASS format, I've begun to see that a
> lot of data is lost in the translation. I suspect that this is generally
> inevitable when one converts between formats. Additionally, GRASS doesn't
> do very good compression, which is important for low-end (low disk space)
> systems, like mine.

I believe that the run-length encoding used by GRASS to compress raster 
files was chosen partly due to the speed at which it can be uncompressed, 
an important consideration for reading raster layers. I assume that 
you're not referring to the archiving of GRASS data. I don't doubt that 
there are better algorithms out there, but RLE has served GRASS pretty 
well. With the price of disk storage today, I think that processing speed 
is more of a consideration than storage size. My $.02 :^)

> 
> How about giving GRASS the ability to access a standard database that
> could incorporate various kinds of information, and would be extensible as
> needed? I'd guess that modern database programs are probably well-suited
> for this sort of thing, as far as dealing with varied data types and
> sometimes sparse data. If the interface were also standard (perhaps SQL?),
> it would be portable and able to take advantage of future improvements in
> database software. Also, we (as GRASS users) wouldn't have to maintain the
> database code; we'd just need routines to dump existing data into the
> database.

Check out src.garden/grass.informix. These SQL tools have been ported to 
one or two other databases by some other folks, as well; other people on 
this list could probably tell you more. 
> 
> As a disclaimer, I don't know much about databases. After talking recently
> to a friend who knows a litle, it seemes reasonable. Can someone with more
> background comment?
> 
> -Eric
> 
        -Malcolm
--
Malcolm D. Williamson - GIS Specialist           E-mail: malcolm at cast.uark.edu
Center for Advanced Spatial Technologies      Telephone: (501) 575-6159
Ozark Rm. 12                                        Fax: (501) 575-5218 
University of Arkansas              
Fayetteville, AR 72701
>