Adding a new field to nested subcollection in firebase [duplicate]
There is no singular best practice here. Both approaches you describe are valid, and neither is pertinently better than the other.
A few things to keep in mind in either scenario:
- You may not be able to handle all updates in a single batched write (since that can handle at most 500 documents at once), so I'd recommend not wasting energy on that.
- In some scenario's it is also acceptable (and sometimes even required) to not update the existing documents, so I recommend always considering that too.