I have been using Calibre for many years, and I literally
just discovered hierarchical tags.

I have nearly 5000 books tagged using non-hierarchical tags, with ">" in place of "." for genres and subgenres. For example:
nonfiction>science>physics
Is there a way to automatically find and replace all instances of ">" with "." in my tags column, or am I going to have to go through each entry and manually change them all?
Thanks,
mdclanahan