After read this nice post from underdark A Beginner’s Guide to pgRouting, although I still have some little problems, I think I can begin the "Creating a routable road network" stage right now.
I got a polyline shapefile already, but after I Add PostGIS Layers, I open PostGIS Manager and I don't know if these two red triangles would bother me later on:
- There is a significant difference between estimated and real row count. Consider running VACCUUM ANALYZE.
- No spatial index defined.
If they do, what can I do？