So we can conclude that maps and ta

So we can conclude that maps and tables can be linked if they have the same domain.
However, there is a very important restriction that should be mentioned here. It is
only possible to have an attribute table with a class domain, or with an ID domain.
Tables with a value domain are not possible. The reason for that is:
- Suppose you have defined a value domain with minimum 0 and maximum 10000,
and a precision of 0.01. In that case, a table connected to the map should have a
very large number of records (10000*100 = 1,000,000). The number of records and
the extreme size of a table will become a problem.
- A more important reason, however, is that value maps themselves do not contain
information to which attributes they can be linked. They are in fact attribute maps,
and not thematic maps. The Landuse map (with a class domain) can have an attribute table, in which for each land use type information is given, such as the
biomes production per hectare, the value of the land per hectare, etc.
- The Cityblock map (with domain ID) can have an attribute table in which information
is stored for each city block, such as the number of people living in the
block, the number of houses, public buildings, shops, etc.
- A value map, on the other hand, such as the segment map Contour, contains values,
representing a certain phenomenon (in this case terrain elevation). It is difficult
to imagine which attributes could be linked with such information, other than
purely statistic information (e.g. the length of each line).
The linking of maps with attribute tables is useful if you want to substitute the units
of a map with an attribute value from the connected table (a process called
renumbering). In that case you generate an attribute map.
Although value maps cannot be linked to attribute tables, you can generate tables
from value maps. The most important ones are cross tables and histograms. These are
not used, however, to renumber the value maps. It would make no sense to replace the
DN values (reflectance values) of a satellite image with the area attribute from its histogram.