l...@gnu.org (Ludovic Courtès) writes: > Leo Famulari <l...@famulari.name> skribis: > >> I _think_ that `gc --references` works by querying the database for a >> list of references in the store item you give it as an argument. I think >> that the information in the database is created after building, by >> scanning the files of the package's output in /gnu/store, looking for >> strings that appear to be paths in /gnu/store. I say "I think" because I >> am not sure. I don't understand that part of the code very well yet. > > That’s 100% correct! :-) Namely, ‘guix gc --references’ makes an RPC to > the daemon, which then looks things up in the database (see the ‘Refs’ > table in nix/libstore/schema.sql.) > > Scanning for references indeed happens at the end of a successful build, > in ‘scanForReferences’ in libstore/references.cc. Since scanning is > expensive (I/O-intensive), the result is stored in the database.
Sorry, this might be a dumb question, I don't quite understand the concept of these references. Why are references important? Shouldn't every store item know which other store-items are related to it from the "inputs"-field in its definition? Why is it necessary to keep track of the references? Thank you!
