当有很多记录的方法时，哪个选项更好？

Question

请建议我哪个选项最好。

我有一个表Student（id，name，create_date）。它有太多的记录（假设数百万）。 我有另一个名为student_stats（month，year，student_count）的表，现在是空的。我将查看我的学生表并填写student_stats表。

student_stats会有这样的数据

month year  count
jan   2000    5
feb   2000    4
...
jan   2015    20  

选项1：

List<MonthYearCount> monthYearCounts = select month(create_date), year(create_date), count(*) from Student where create_date between '2000-01-01' and '2015-02-01' group by month, year;

for(singleMonthYear : all month between '2000-01-01' and '2015-02-01'){
 MonthYearCount monthYearCount = monthYearCounts.get(singleMonthYear);
 studentStats = new StudentStats();
 studentStats.setMonth(monthYearCount.getMonth())
 studentStats.setYear(monthYearCount.getYear());
 studentStats.setCount(monthYearCount.getCount());
 studentStats.insertToDB();
}

class MonthYearCount{
int month;
int year;
int count;
}

选项2：

List<Student> students = select * from Student where create_date between '2000-01-01' and '2015-02-01;

for(singleMonthYear : all month between '2000-01-01' and '2015-02-01'){
  List<Student> filtered = new ArrayList<>();
  for(student : students){
     if(student.getCreateDate() is between singleMonthYear i.e. 2012-05-01 to 2012-05-31){
         filtered.add(student);
     }
  }


  studentStats = new StudentStats();
  studentStats.setMonth(singleMonthYear.getMonth())
  studentStats.setYear(singleMonthYear.getYear());
  studentStats.setCount(filtered.size());
  studentStats.insertToDB();
}

提前致谢！