Digital Geography

4. May 2012

Geodatabases: a little insight

Most GIS-users I know don’t use Geodatabases. But as your project may grow, participation and co-working gets more and more usual in your projects and you would like to share not only your results but also your data the usage of geodatabases will be one thing to keep in mind.
Normaly each feature or raster is stored in separate files and maybe folders as well. This concept will stay alive in a geodatabase but in a more professional way:

ArcGIS gives you the possibility to store your features in a file geodatabase, perosnal geodatabase or an ArcSDE Geodatabase.
So what is a geodatabase capable of?

According to ESRI a geodatabase offers you the ability to

  • Store a collection of spatial data in a centralized location.
  • Apply sophisticated rules and relationships to the data.
  • Maintain integrity of spatial data with a consistent, accurate database.
  • Work within a multiuser access and editing environment.
  • Integrate spatial data with other IT databases.
  • Support custom features and behavior.

But one thing is much better: by using a good geodatabase model you are independent from your used GIS and also operating sysem. You can compare different concepts of ESRI-geodatabases here: Link
One more thing…There are of course open source geodatabases as well! You just need to look at postgreSQL (which can be also the basis for ArcSDE…) and its extension postgis. Postgis will enable you to benefit from a geodatabase as much as a database from ESRI will do. You can store your features, use SQL, create topologies and analyze your datasets in a very convenient way. But one drawback: It does not look like there is an easy way to adress your postgis database from within ArcMAP.