Hi there, Thanks to all for reply. But I still have a question:
1. When I using Twtiter via Tweetie which is iPhone application, I can see the unique ID for each of users in their personal profile page. It seems like incremental number. As far as I know, Twitter using Cassandra for its back-end. My question is how do they do that? 2. I know UUID is the best solution to generate unique ID. However, I worry about value conflicts with billions of columns. Is there anyone who has experience about this? Thanks, On Thu, Mar 25, 2010 at 10:37 AM, Muhammed Nasrullah <nasrul...@gmail.com>wrote: > You replace it with an UUID. In a true scalable distributed system, you > should not have an auto_increment. If you are writing to 10 > nodes simultaneously, it becomes near impossible to keep a single > incrementing value being used by the entire system without causing a lot of > write contention. > > This is how you generate a Time-UUID in Java: > http://wiki.apache.org/cassandra/FAQ#working_with_timeuuid_in_java > > > On Wed, Mar 24, 2010 at 9:57 PM, Jaepil Jeong <zgdr...@gmail.com> wrote: > >> Hi there, >> >> I just started research about Cassandra to replace MySQL, and I have a >> question: How can I replace the "auto increament" attribute in MySQL >> with Cassandra? If I can't, how can I generate an ID which is globally >> unique for each of columns? >> >> Thanks, >> >> Sent from my iPhone >> > > -- Jaepil Jeong Software Architect twitter: http://twitter.com/JaepilJeong msn: zgdr...@hotmail.com Everything arises, everything falls away.
