Getae and Dacians? Are they the same? Or is this unknowable?

[Rumo]

We were discussing about Cniva and I'd like to point out a strange coincidence. The conflict between Decius and Cniva is accounted by a single source, Jordanes' Getica (101). Not only that, Decius' enemies are called Goths by two sources, Jordanes and a Cassiodorean Chronica (see under XXV Decius). The other sources call them Scythians (Zosimus, Zonaras) or barbarians (Eutropius, Aurelius Victor). That is not to suggest the entire episode is fictional, only that it may be "reworked". Other Roman enemies such as Burebistas were transformed into Goths, too.

If I missed any important ancient testimony on Decius and Cniva let me know.