It is sometimes suggested that spatial data is just another form of data that can now be maintained in a data base and that in reality there is nothing “special about spatial”. Nothing could be further from the truth. For example spatial data is not the same as integer, alphanumeric or symbolic data for a number of reasons. These are: spatial data is scale dependent: do I query for 37.3N 45.2W..or? spatial queries are endemically computationally expensive…