[GRASS5] Maximum number of categories

[Radim Blazek]

On Saturday 24 April 2004 08:43, Moritz Lennert wrote:
> Radim Blazek said:
> > Bad news!
> >
> > I have discovered, that number of categories for each element is stored
> > as 1byte. It was enough when only one cat of each field was allowed.
> > Now each field may have many cats and 256 is not enough.
> >
> > I think that there are already too many 5.7 vector files in use,
> > so I must increase 'coor' format version (5.0->5.1) [1], and to handle
> > more versions
> > for reading. Unfortunately it will not be possible to read new files in
> > older versions
> > of GRASS 5.7. I'll add first the code for reading and after some 1-2
> > months also for writing,
> > to minimize problems.
> >
> > Do you have other suggestions?
>
> If the 'coor' format solution is a "second-best" solution in form of a
> hack (please coorect me if it isn't), I would think that since 5.7 is
> officially declared as development version, people have to live with the
> risk of things being broken. So, I think it would be better to revise the
> format completely and cleanly to include all necessary changes, instead of
> finding other solutions that might be not as clean and then carry this
> around for the next years.
>
> Moritz

The 'coor' format was designed for 5.7 without any compromises. 
AFAIK, the suggested change (number of cats 1 byte -> 2(4) bytes) 
is the only required. 
I know that 5.7 is devel version and it is devel version exactly 
for these reasons. However, we (including me, I think) said 
few times that 5.7 can be used already for work.
To have support (reading) for both 5.0 and 5.1 'coor' formats 
means only few rows of code.

I think that I'll do both steps of the change (i.e. first reading,
then writing) without long delay but in 2 cvs commits.
The problem may appear only for groups using more installation
of GRASS and sharing the data. In that case, they can either:
1) make first update for reading on all machines and then
   also for writing
or
2) stop the work for a while and update all installations directly
   to reading+writing.
Is it OK?


Radim