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From: Jonathan Ellis <jbellis@gmail.com>
Date: Sat, 7 Aug 2010 22:36:08 -0400
Message-ID: <AANLkTim1NbraNm4HcwmF5m8JwZ=bE_CsRTzWRnL43K5y@mail.gmail.com>
Subject: Re: How to migrate any relational database to Cassandra
To: user@cassandra.apache.org
Content-Type: text/plain; charset=ISO-8859-1

are you using OrderPreservingPartitioner then?

On Sat, Aug 7, 2010 at 10:32 PM, Zhong Li <zli@voxeo.com> wrote:
> Here is just my personal experiences.
>
> I recently use Cassandra to implement a system cross 5 datacenters. Because
> it is impossible to do it in SQL Database at low cost, Cassandra helps.
>
> Cassandra is all about indexing, there is no relationship naturally, you
> have to use indexing to keep all relationships. This is fine, because you
> can add new index when you want.
>
> The big pain is the token. Only one token you can choose for a node, all
> system have to adopt same rule to create index. It is huge huge pain.
>
> If Cassandra can implement token at CF level, it is much nature and easy for
> us to implement a system.
>
> Best,
>
> Zhong
>
>
> On Aug 6, 2010, at 9:23 PM, Peter Harrison wrote:
>
>> On Sat, Aug 7, 2010 at 6:00 AM, sonia gehlot <sonia.gehlot@gmail.com>
>> wrote:
>>
>>> Can you please help me how to move forward? How should I do all the setup
>>> for this?
>>
>> My view is that Cassandra is fundamentally different from SQL databases.
>> There
>> may be artefact's which are superficially similar between the two systems,
>> but
>> I guess I'm thinking of a move to Cassandra like my move from dBase to
>> Delphi;
>> in other words there were concepts which modified how you write
>> applications.
>>
>> Now, you can do something similar to a SQL database, but I don't think you
>> would
>> be leveraging the features of Cassandra. That said, I think there will be
>> a new
>> generation of abstraction tools that will make modeling easier.
>>
>> A perhaps more practical answer: there is no one to one mapping between
>> SQL
>> and Cassandra.
>
>


-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com