How can I avoid re-importing assets?

How can I avoid Unity re-importing it assets?

I am zipping up my Library folder, and deleting it. If I copy the entire project to
my file server with the Library.zip, Unity still re-imports its assets when I pull down a fresh copy from the server, after restoring the Library folder from the zip file.

I don’t want to waste the time re-importing the assets, that is why I zipped up the Library
and saved it. What files/folders is Unity looking at to determine whether or not to rebuild the cache? (re-import the assets). Is there a timestamp issue?

This does not work. If I switch a project over to use meta files, and delete my library (or svn ignore it) Unity rebuilds the Library because it cannot find the asset database. The rebuild of the Library folder is what I am trying to avoid. It is slowing down my workflow too much. I really need to be able to rebuild the asset database myself programmatically, as a background task, but I have no technical information about it.

If you go into the editor settings, switch version control over to Meta Files. Then you don’t have to copy your library at all! however all of your assets and folders will have an additional file, but this means that when you open unity, only assets that have been modified should be re-imported.

hope this answers your question.

It looks like disabling auto-refresh helps the problem somewhat.
Edit->Preferences-General Settings : Auto-refresh