After spatial data management (the input, storage, manipulation and display of points, lines, areas, cells), attribute data handling is the other primary capability required of a GISystem. Without the ability to properly handle the related non-spatial information, the technology of GIS would never have taken off as it has. The purpose of the this lecture is to provide you with an overview of attribute data handling in a GIS environment.

Over the years several different approaches to handling attribute data have been used by GIS vendors, although at present the relational database approach is by far the dominant. There is very little else on the net which describes this subject from a GIS perspective.

In ArcView (a precursor to ArcMAP), the database format was derived from dBase, a widely used PC-based relational database management system software program, while in Arc/Info (a unix-based software package that was the precursor to ArcGIS ) the database format was derived from INFO. ArcGIS supports the use of both previous database program formats (i.e., the dBase .dbf format and the info format, which is evident when you create a raster dataset [note the info directory associated with raster files]), but ESRI is also promoting the use of its GeoDatabase (gdb) concept and, in particular, it is promoting the use of multiuser database connections, which means that almost any database supporting Object Linking and Embedding (OLE) can be used–be it an Oracle database, a Microsoft SQL Server, Jet (Microsoft Access) and Microsoft Excel. (Other databases can be accessed from ArcGIS if an OLE DB is available for that database.) SQL is available in ArcGIS through such tools as ‘ Select by attributes’ under Options (attribute table).

Leading DBMS Vendors

• Oracle
• Microsoft SQL Server
• MySQL (free)
• PostgreSQL (free)
• A good review of the rapidly changing DBMS market today: 2019 Database Trends