我应该缓存文件的md5还是足够快，不需要？

Question

I need to check md5 checksum of ~10-20 files on server every time a user logs in. Each file can be ~10MB. Should I cache md5 of these files or do it in real-time without wasting time & bothering?

P. S. there will probably be up to 10k logins a day.

Answer 1

That depends on the requirements, checking a cached value is not the same as getting a file checksum.

So based on the first sentence - I need to check md5 checksum of ~10-20 files - no, you cannot cache it.

However, if you just need to display a checksum, then yes, you can and should cache it and check the file-integrity periodically with a cron-job if necessary.