Overlay analysis is the very common analysis of GIS application. In AutoCAD Map 3D 2010 which enhanced a new feature "Overlay analysis". Actually many software have this kind of analysis for long time ago.

Why is this a useful tool of Map 3D 2010?
As FDO technology, Map 3D can do data integration very easy with different kind of GIS data/ database. How do you think if the project have involved a number of differ data format, and need to do spatial analysis periodically? As well as all the shakeholder will submit you a new updated data by weekly/ daily.

In Map 3D 2010, Overlay analysis can be help anytime/ any format once all layer is prepared. No proprietary file format barrier!

For example:
- What are the plots stored in PostGIS that would be impacted by a flood, described in an Oracle database in the proprietary format ArcGIS (ArcSDE)?

- What are the buildings stored in a file SHP affected by an intervention on a defined network in a file MapInfo?

This is very impressive.