Field order of an upsert
What changes in Field order of an upsert compared with MongoDB and what your application has to do.
This difference is of the Different kind.
What MongoDB does
The fields the upsert takes from the filter come out in an internal order.
What TeselaDB does
They come out in the order of the filter.
What your application has to do
Do not rely on the order of the fields of a document.