Differences between FerretDB and MongoDB®
FerretDB uses the same protocol as MongoDB®, but there are know differences between the two you must take into consideration when using FerretDB.
Some MongoDB® features are not yet implemented in FerretDB. The differences cited below refer to features that are already implemented, and fully supported by FerretDB.
For example, even though error names and codes used by FerretDB are the same as MongoDB®, but the precise content of the error messages may differ in some cases.
Certain characters are not be supported within document keys and files, as well as database and collection names.
Be aware that when using FerretDB, the following characters are not supported:
.sign in document keys
$at the start of a document key
NaNvalues within document fields of double type
_ferretdb_prefix for any names, as this prefix is reserved
- non-latin letters in the database name
Collection names must be composed of valid UTF-8 characters.
An extensive list of all known differences between the two document database engines is available on FerretDB’s Known Differences documentation page.