Convert Lat/Long to Census Tract

[OlsabeckT29]

My dataset already has been geocoded but it is missing census tract information. Is there a way in SAS to identify the corresponding census tracts to the existing lat/longs without running the whole dataset through proc geocode? The dataset has about 15 million observations so to re-geocode it will take significant time. I am trying to avoid using the following piece of code due to the time it will take for this size of dataset.

Proc geocode
method=street
data=child_clean
out=georesults
lookupstreet=lookup.usm
attribute_var=(tract);
run;

Thank you for your help! 

[ballardw · Accepted solution]

The only that comes to my mind is if you have a map data set of census tracts that have boundary values of the map polygons in the same units as your data then Proc GINSIDE might work.

Not sure if faster though.