Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Geodatabase Software

Despite the idea of a geodatabase—storing all of geometry, a spatial reference system, attributes, and behavioral rules for data in a single relational database management system—things are still not simple. Esri software has to “partner” with existing RDBMSs, so the conventions for dealing with spatial data must conform to the different general conventions of these RDBMSs. For these and other reasons, there are two Esri geodatabase flavors for single-user ArcGIS: Personal and File. For multiuser Esri software there is the ArcSDE (Spatial Database Engine). (Multiuser ArcGIS has Desktop, Workgroup, and Enterprise versions.)

Personal Geodatabases: They depend on Microsoft Access RDBMS. The datasets are stored within a data file, which is limited in size to 2GB. This was Esri’s first version of storing both the geometry and the attributes in a single database system. The extension on the name is .mdb, standing for “Microsoft database.” While personal geodatabases suffer from several disadvantages compared to file geodatabases (discussed below), they also have their strengths. If you plan to remain in the Windows operating system environment, and want to search and work with the ArcGIS software that stores attribute tables with Microsoft Access, personal databases can be quite satisfactory.

File Geodatbases: Datasets are stored in folders in a file system. Each dataset is held as a file that can be as large as one TB (Terabyte—roughly a billion bytes, which would ...