If you open up a BLOB's Edit Value window, there's a button to open the BLOB in an External Editor. I've never been able to get this to work. It tries to use the list of External Editors in the Preferences section.
So I guess I have a couple of questions:
1. How do you add MIME types to this list of External Editors. There's no text/plain, which seems like a pretty important one. I'd also like to add one for *.xlsx files. There's no application/octet-stream to set a default editor.
2. How is the association between a BLOB and a MIME type established? A BLOB is just a series of bytes. Is it trying to auto-detect, or do I need to add a mime_type or file_name column to my table?