Research, tool ernie broken link
https://www.torproject.org/getinvolved/research.html.en First point (data) contains "For example, we provide a tool called Ernie that can import relay descriptors into a local database to perform analyses" which links to https://gitweb.torproject.org//ernie.git?a=blob_plain;f=doc/manual.pdf which gives a 400 (Project needed)
Maybe you moved it. Couldn't see anything that matches. E r i n n is quite close, but K a r s t e n is probably responsible for importing descriptors. ;) :)