在Google App Engine中存储人员年龄是一种好习惯吗？

I need to search through thousands of records of type 'Person' and fetch the ones, say: Age between 25 and 30. So is it a good practice if I store the age at the write time itself and run a scheduler to update the age on every persons bday. A scheduler that runs everday for all the person having birthday that day. I know this is wrong for relational database. Could someone experienced in GAE/J guide me on this. I need to search through thousands of records o