I discovered something I would it strange today. As I was looking at my colleague code, I found that when whe query a stored proc, there's no need to open the connection before the instruction dataAdapter fill.
here's the example
Public Function getCodeBiensNi() As List(Of CodeBiensNi)
Dim CodeBiensNis As New List(Of CodeBiensNi)
Dim cursCmd As OracleCommand = New OracleCommand("b240004k.get_bdm_code_biens_ni_2", connection)
cursCmd.CommandType = CommandType.StoredProcedure