Feature table with own feature attributes?

[2StepForward]

Hi list,

one question, is it possible to add a additional feature attribute to a feature table?

Example:

 1        gid      location       the_geom          state
       
            1         xx.tif            wkb                 0

where state is a user own feature attribute.
An second, is it possible to quere (filter) this user own feature attribute.

Thank's a lot