Conjuntos de resultados múltiples con Oracle

Debes escribir un pl/sql anónimo bloque que devuelve ref cursors .

Prueba esto en ADO.NET :

    oraConnection = new OracleConnection();
    da = new OracleDataAdapter();
    ds = new DataSet();

    oraConnection.ConnectionString = "Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=172.20.10.8)(PORT=1521))(CONNECT_DATA=(SID=orcl12c)));";
    cmdText = "begin open :1 for select * from adr; open :2 for select * from person; end;"; 
    cmd = new OracleCommand();
    cmd.CommandText = cmdText;
    cmd.Connection = oraConnection;
    cmd.CommandType = CommandType.Text; 

    OracleParameter refcur1 = cmd.Parameters.Add("Refcur", OracleDbType.RefCursor);
    refcur1.Direction = ParameterDirection.Output;
    OracleParameter refcur2 = cmd.Parameters.Add("Refcur", OracleDbType.RefCursor);
    refcur2.Direction = ParameterDirection.Output;

        da.SelectCommand = cmd;
        da.Fill(ds);