docs: protected List<String> getAllColumns(String tableName) {
          List<String> columns = new ArrayList<String>();
          try {
              // Lower-case table names are required for PostgreSQL; we might need to
              // alter this if we use another comparison database (besides HSQL) someday
              ResultSet rs = dbconn.getMetaData().getColumns(null, null, tableName.toLowerCase(), null);
              while (rs.next()) {
                  columns.add(rs.getString(4));
              }
          } catch (SQLException e) {
              printCaughtException("In NonVoltDBBackend.getAllColumns, caught SQLException: " + e);
          }
          return columns;
      }