Change branch/repository from unstable to stable

Here’s a scenario I’ve seen in the past:

Let’s say I change into the “Testing” branch. A few days later, the “Testing” branch requires a fix, and is rebuilt.

Must I decrement “/opt/pakfire/db/core/mine” to reapply the branch update?

When the “Testing” branch is released, if I switch back to the “Stable” branch, should I assume a decrement of “/opt/pakfire/db/core/mine” is needed?

Thanks!