code: @Override
      public List<DColumn> getColumns(String storeName, String rowKey,
                                      String startColumn, String endColumn, int count) {
          String tableName = storeToTableName(storeName);
          Map<String, AttributeValue> attributeMap = m_ddbClient.getItem(tableName, makeDDBKey(rowKey)).getItem();
          List<DColumn> colList =
              loadAttributes(attributeMap,
                             colName -> ((Utils.isEmpty(startColumn) || colName.compareTo(startColumn) >= 0) &&
                                         (Utils.isEmpty(endColumn) || colName.compareTo(endColumn) <= 0))
                            );
          m_logger.debug("getColumns({}, {}, {}, {}) returning {} columns",
                         new Object[]{tableName, rowKey, startColumn, endColumn, colList.size()});
          return colList;
      }
docs: ----- Public DBService methods: Queries