遇到一段跑起来费解的代码

今天校准数据库的时候，发现了一个执行结果不同的现象。经过定位，发现问题出在下面这段代码上。这段代码的执行结果被一个v_request_num的变量所左右。 v_request_num 越小，最后的结果就越少， v_request_num 越大，最后的结果就越多。如果说单次执行的话，这个是废话。但多次执行，直到将表中数据计算完毕后的结果也是这样，着实费解。

代码如下：

  /********************************************************************************************/
  /*                  最小阀值                                                                 */
  /********************************************************************************************/
  begin
    select min(index_value) into v_min_value
      from  indexvalue
     where exec_index = v_exec_index;
  exception
    when others then
      v_error_no := 23122003;
      p_error_info := '[23122003]取最小index_value失败' ||
                         ' v_exec_index = ' || v_exec_index;
    return v_error_no;
  end;

  /********************************************************************************************/
  /* 取已执行流水号                                                                           */
  /********************************************************************************************/
  begin
    select nvl(count(*), 0)
      into v_count
      from icsentrustno
     where exec_index = v_exec_index and branch_no = 0;
  exception
    when others then
      null;
  end;

  if v_count = 0 then
    begin
      insert into icsentrustno values(v_exec_index, 0, 0);
    exception
      when others then
        v_error_no := 23122003;
        p_error_info := '[23122003]插入流水号表失败'
                        || 'exec_index = ' || v_exec_index;
      return v_error_no;
    end;
  else
    begin
      select record_id
        into v_record_id
        from icsentrustno
       where exec_index = v_exec_index
         and branch_no = 0;
    exception
      when others then
        v_error_no := 23122004;
        p_error_info := '[23122004]执行流水号不存在'
                        || 'exec_index = ' || v_exec_index;
      return v_error_no;
    end;
  end if;

  /********************************************************************************************/
  /*重置起始流水号                                                                            */
  /********************************************************************************************/
  begin
    select nvl(min(record_id),0)
      into v_beginrecord_id
      from entrust;
  exception
    when others then
      v_error_no := 23122013;
      p_error_info := '[23122013]取最小流水号失败' ||
                      ' v_exec_index = ' || v_exec_index;
    return v_error_no;
  end;

  if v_record_id < v_beginrecord_id then
    begin
      update icsentrustno
         set record_id = v_beginrecord_id - 1
       where exec_index = v_exec_index;
    exception
      when others then
        v_error_no := 23122013;
        p_error_info := '[23122013]更新执行流水号表失败' ||
                        ' v_exec_index = ' || v_exec_index;
      return v_error_no;
    end;

    v_record_id := v_beginrecord_id - 1;
  end if;

  /********************************************************************************************/
  /* 取执行结束流水号                                                                         */
  /********************************************************************************************/
  begin
    select nvl(MAX(record_id),0)
      into v_endrecord_id
      from entrust;
  exception
    when others then
      v_error_no := 23122007;
      p_error_info := '[23122007]取执行结束流水号失败'
                     || ' 执行指标: ' || v_exec_index;
    return v_error_no;
  end;

  if v_endrecord_id = v_record_id then --没有新增流水
    return 0;
  end if;

  if v_request_num <> 0 and  v_endrecord_id > (v_record_id + v_request_num) then
    v_endrecord_id :=  v_record_id + v_request_num;    --只取v_request_num条记录
  end if;

  --取配置计算时间设置
  begin
    select nvl(int_config, 15)
      into v_up_time
      from consysconfig
     where config_no = 4121;
  exception
    when others then
      v_up_time := 15;
  end;

  begin
    select cast(nvl(str_config, 1.02) as number(19,2))
      into v_ratio
      from  consysconfig
     where config_no = 4120;
  exception
    when others then
      v_ratio := 1.02;
  end;

  begin
    select nvl(int_config, -1)
      into v_diff
      from consysconfig t
     where config_no = 4207;
  exception
    when others then
      v_diff := -1;
  end;

  /********************************************************************************************/
  /* 以下 计算指标,记录超标流水,置执行流水号                                                  */
  /********************************************************************************************/
  begin
    select min(entrust_time),max(entrust_time)
      into v_min_entrust_time,v_max_entrust_time
      from entrust
     where record_id > v_record_id
       and record_id <= v_endrecord_id
       and entrust_time between 0 and 150000;
  exception
    when others then
      v_error_no := 22702307;
      p_error_info := '[22702307]获取区间最小及最大委托时间失败'
                     || ' 执行指标: ' || v_exec_index;
    return v_error_no;
  end;



  v_begin_time := case when v_min_entrust_time - v_up_time*60 < 0 then 0 else fn_gettime_diffbyminute(v_min_entrust_time, v_up_time) end;
  v_end_time := v_max_entrust_time;

  begin
    insert into t_231220
    select *
      from entrust
     where entrust_time >= 92000
       and entrust_time between v_begin_time and v_end_time
       and stock_type not in ('D','F')
       and abs(entrust_amount * entrust_price)  >= v_min_value
       and entrust_type in ('0','6','7','9')
       and entrust_prop = '0';
   
  exception
    when others then
      v_error_no := 22702307;
      p_error_info := '[22702307]插入临时表[t_231220]失败'
                     || ' 执行指标: ' || v_exec_index;
    return v_error_no;
  end;

  declare cursor cur_record is
  select record_id, oc_date, entrust_time, client_id, fund_account, branch_no, operator_no,
         exchange_type, stock_code, entrust_price, entrust_bs, entrust_amount, entrust_price,
   entrust_type
    from t_231220 a
   where record_id > v_record_id
     and record_id <= v_endrecord_id
     and exists(select 1 from t_231220  b
                 where b.fund_account <> a.fund_account
                   and b.exchange_type = a.exchange_type
                   and b.stock_code = a.stock_code
                   and b.entrust_time between case when a.entrust_time - v_up_time*60 <0 then 0 else fn_gettime_diffbyminute(a.entrust_time,v_up_time) end and fn_gettime_diffbyminute(a.entrust_time,-v_up_time)
                   and b.entrust_bs <> a.entrust_bs
                   and b.entrust_bs = case a.entrust_bs when '1' then '2' when '2' then '1' end
                   and (b.entrust_type = case a.entrust_type when '6' then '0' when '7' then '0' when '9' then '0' end or
                        b.entrust_type = case a.entrust_type when '0' then '6' end or
                        b.entrust_type = case a.entrust_type when '0' then '7' end or
                        b.entrust_type = case a.entrust_type when '0' then '9' end)
                   and (case when b.entrust_price > a.entrust_price then b.entrust_price/a.entrust_price
                             else a.entrust_price/b.entrust_price
                        end) < v_ratio
                   and (v_diff = -1 or ABS(b.entrust_amount - a.entrust_amount) <= v_diff))
   order by record_id;

这里entrust_time是个时间转化出来的number类型，格式是yyyymmdd，8位整数。

v_up_time的单位是分钟。

fn_gettime_diffbyminute(entrust_time,v_up_time) 的作用是得到 entrust_time前 v_up_time的时间，比如当entrust_time为150000 （15点整），v_up_time为10 （10分钟）时，这个函数的结果就是 145000 （14点50分）。类似的，参数变成-v_up_time，就是取entrust_time的后v_up_time的时间，比如说151000。