# File lib/og/backends/psql.rb, line 153
        def self.calc_field_index(klass, og)
                res = og.query "SELECT * FROM #{klass::DBTABLE} LIMIT 1"
                meta = og.managed_classes[klass]
        
                for field in res.fields
                        meta.field_index[field] = res.fieldnum(field)
                end
        end