Add '/bin' prefix database

[jakobkukla]

I want to use this as command-not-found replacement. As far is I can tell this only provides full database builds. On my system the command-not-found script takes 3s to execute with the full db.

Could we have an option to download and use a prefix filtered db instead like nix-index --filter-prefix '/bin/'? Or maybe even have an option to provide both and use the smaller one for the command-not-found script?

[Mic92]

How fast is the bin database in comparison? I wonder if nix-index could not somehow compute the smaller database from the bigger one.

[gvolpe]

@Mic92 it's significantly faster. Using nix-index with the full database is borderline unusable for me; when I type a command not found, it takes about 2/3 seconds to display the results. Instead, with a smaller database generated via nix-index --filter-prefix '/bin/', the results are displayed immediately.

Could we have an option to download and use a prefix filtered db instead like nix-index --filter-prefix '/bin/'? Or maybe even have an option to provide both and use the smaller one for the command-not-found script?

It would be great if this could be supported 🙏🏽

For now, I use a local database, but also with this fork for nix command support: gvolpe/nix-index#1