disable changes of local file

[cgorac]

Got large data file in project that I've imported to the repository
along with other files. I'd like this file to be kept in repository,
but that local changes (this file is changend often locally, because of
testing) do not change the copy in repository and that during an update
from repository local copy doesn't change either. Now, I know that I
can accomplish later trough putting this file name in .cvsignore file,
but is there some more "proper" way and further how to accomplish
first.

Thanks.