Thinking I had something new, I wrote this article about recovering deleted files. However, it turns out Frits Hoogland had already blogged about recovery of deleted files on linux, as Frits pointed out in a comment on my blog, where he also mentioned a metalink note on this matter. The procedure outlined in the note describes how to recover the deleted file and put it in the same location as the deleted file. The problem is that it doesn’t include offlining/onlining the file, so the database ends up with two distinct copies of the file.
So you have accidentally removed a datafile from your production database? First thing, DON’T PANIC! There’s an easy way to recover deleted datafiles, for as long as your database remains up. The procedure, outlined here, works on linux, however this method conceivably can work for other platforms.