How to attached Secondary ".ndf" file after detaching from DB

Hi All,

I have DWH and currently we have archived old data and kept in seperate parition file. We want to detached file to avoid backup of same (since data is not used) but we want to attached same file if business required old data..

Can anyone work on such senario before.

It will be really helpful if some one through light how I can achieve this

Why not leave that NDF file attached and just backup the PRIMARY file group?

BACKUP DATABASE { database_name | @database_name_var } <file_or_filegroup> [ ,...n ] TO <backup_device> [ ,...n ] [ <MIRROR TO clause> ] [ next-mirror-to ] [ WITH { DIFFERENTIAL | <general_WITH_options> [ ,...n ] } ] [;]