docs: @Local
      @Override
      public int[] directExecute(String... sqls) {
          if (sqls.length == 0) return new int[0];
          Connection conn = writePool.poll();
          try {
              conn.setReadOnly(false);
              final Statement stmt = conn.createStatement();
              final int[] rs = new int[sqls.length];
              int i = -1;
              for (String sql : sqls) {
                  rs[++i] = stmt.execute(sql) ? 1 : 0;
              }
              stmt.close();
              return rs;
          } catch (SQLException e) {
              throw new RuntimeException(e);
          } finally {
              if (conn != null) writePool.offerConnection(conn);
          }
      }