Data in field_revision with Create new revision unchecked The field_data_myfield and field_revision_myfield have the same row entries (D7 fields). All of my content types have the "Create new revision" unchecked. Is this how it's suppose to work? If yes, two questions 1) is this okay for scalability and 2) how do I stop drupal from renaming the files with _0 even when the original is deleted -- I read that this is because revision is on. If it's not suppose to work this way, how do I fix it.  

I'm using mysql.

To clarify the end goal, I don't want the entire field deleted, I would like the fields not to track data revisions. Currently if field_body is updated, it also tracks it in field_revision body. Ideally, drupal would only save the update in field_body, and field_revision_body would be left empty. The content type is marked to not track revisions.
Is this how it's suppose to work?

It depends on which storage backend you use. The default sql backend works this way.


It shouldn't effect speed (much) but will instead effect data storage which usually isn't a problem.
Drupal will not completely delete a field, but instead mark it as deleted. If you want to completely delete it, you need to delete it from the field_config and field_config_instance tables.