I found the solution: my Mnesia.create_table seems to have wrong argument structure. This is the right way:
Mnesia.create_table(:testtable, attributes: [:id, :testdata], disc_copies: [node()], type: :set)
I found the solution: my Mnesia.create_table seems to have wrong argument structure. This is the right way:
Mnesia.create_table(:testtable, attributes: [:id, :testdata], disc_copies: [node()], type: :set)