[GRASS5] Raster files suggestion: new directory layout

[Radim Blazek]

Any changes in raster directory structure should be done
only with other necessary changes in GRASS raster format, 
which will break data compatibility, IMHO.
I think that to force users to convert (gigabytes) of data 
for nothing is not the best idea.

On Monday 05 July 2004 15:12, Paolo Cavallini wrote:
> I strongly support the idea. Perhaps this could give us a chance to improve
> the data format as well? 

Improvements in data format can give a chance to change also directory structure,
vice versa it does not make much sense I think.

> I think a limitation of rasters is that they are
> always 8 bitpp, whereas in many cases (black&white maps) it would be more
> appropriate to stick to 1bpp (far smaller files!).
> But if this is complicated, of course it will be better to change the
> directory layout ASAP.
> All the best.
> pc
>
> At 14:43, lunedì 05 luglio 2004, Markus Neteler has probably written:
> > Hi,
> >
> > another proposal: Let's simplify the raster file directory layout
> > and have all files related to a raster map staying in a single
> > directory (such as the 5.7 vector files). We already have discussed
> > it some time ago.
> >
> > Advantages:
> > - clean and understandable file structure

I think that the structure is understandable.

> > - cleanup of raster API which is hard to understand at time

Is it realy because of directory structure?

> > - user can easily copy a map into another machine
> >   (say, for backup reasons or whatever)

Yes, that's true, but GRASS is designed so that users should not
access GISDBASE directly, only through GRASS modules.
For backup I would suggest r/v.pack/unpack

> > - more?
> >
> > Disadvantages:
> > - a script to migrate raster databases is needed
> >   (as we once did for LZW elimination)

The script is not the problem, the prolem is that the data 
compatibility is broken.

> > When to implement it:
> > - I suggest to do it asap in GRASS 5.7. While at migrating
> >   their vector databases the users can also migrate the raster
> >   databases (which is simply a 'mv' of the files).

5.7.0 was already released, I was waiting with 5.7.0 until 
format was stabilised.

> > It could be implemented in two phases:
> > - first read old raster file directory layout, but write new
> >   layout
> > - in a later version remove support for reading old layout

Is anybody going to implement it in near future?


Radim