Does the `helm-projectile` package use an index?

Question

Do the commands of the helm-projectile package consult an index, or do they scan the entire project tree every time they are invoked?

In case they use an index: when is this index created and updated? Is there an explicit way to create/update it?

Answer 1

It uses a cache that you can invalidete with M-x projectile-invalidate-cache. See chapter caching in this article for more information.