incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jaepil Jeong <zgdr...@gmail.com>
Subject Re: Auto Increament
Date Thu, 25 Mar 2010 12:57:43 GMT
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 <nasrullah@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 <zgdr7th@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: zgdr7th@hotmail.com

Everything arises, everything falls away.

Mime
View raw message