I have a large
.gdb of all blocks in the United States, available from Census. I would like to create a point shape file of all census tract centroids in the US.
I have QGIS with FileGDB enabled, as well as R with
rgdal, so reading the data is not a technical problem. My issue is that reading the layer into
R has taken 2 hours and used up 56 Gb (I have 64) of memory, and it's not done. I know exactly what I want to do:
- Create a tract field by pulling the first 7 characters out of the GEOID field
- Dissolve the blocks on this field
- Calculate the centroids of the new geographies
- Export as a points shape file, or even as another layer in the database.
QGIS shows the data, but the field calculations take just about as long. It seems that I should be able to send these commands into the database rather than load the database and try to do it interactively. I might need some hand holding to do this, or at least good pointers to the right manuals.
On the other hand, is there a way to pull the database out in chunks? I am running Ubuntu 14.04 on a 12-core machine, so parallelization is always a good option...