There are few improvements that can be made in the current DB model
1) Change to 1-to-1 relationship of tf and tft (tft contains backendId which suggest we might need to have one-to-many still)
2) Removal of locale field from tf and tft
3) Do we need Doc as the parent/wrapper of tf and tft?
The idea for Doc as the wrapper for a list of textflow was to keep track of the request count (reuse of translations) of a page. But the request count stats be retrieved via CP stats. We should put the reuse count under TF for more accurate statistics. If we remove Doc from the model, the locale field will need to remain in TF and TFT.