java - Is unique id generation using UUID really unique?

Question

I want generate unique ID just like auto increment in java . So previously i used current nano seconds but i end up with clash since two data comes with in same nano seconds .. Does UUID solves the above problem ?

Note :: In my project i can even get 10000 rows of records for each and every minute and I will dump those records along with UIDS in to table .And there may be a situation where i would stop my product and restart it after some time ....So during that situation how could UUID class clarifies the previously generated Uids(which i stored in DB) with the new one going to created(Yet to be dumped in DB) ?

Answer 1

While the UUIDs are not guaranteed to be unique, the probability of a duplicate is extremely low. See Random UUID probability of duplicates.

For your application, it makes sense to use the UUID, but you may want to deal with the extremely rare condition, just in case.