private DataTable GetSchema_OracleDA()
        {
            OracleConnection conn;
            string connetionString = GetConnectionString_OracleDA();
            conn = new OracleConnection(connetionString);

            try
            {
                conn.Open();
                DataTable schemaTable = conn.GetSchema();
                return schemaTable;
            }
            catch (OracleException ex)
            {
                MessageBox.Show("Exception in GetSchema_OracleDA - " + ex.Message);
                LogMessage("Exception in GetSchema_OracleDA - " + ex.Message, MessageSeverity.Error);
            }
            finally
            {
                conn.Close();
            }
            return null;
        }