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From Ikeda Anthony <anthony.ikeda....@gmail.com>
Subject Re: Java bits: Horizontal Scalibility and DAO layer design
Date Wed, 27 Jul 2011 15:23:01 GMT
Speaking from personal experience (and believe me it all comes down to this) we attempted a
DAO approach as well. However, we found that based upon all the mutator.addInsertion()s we
were creating across column families everything ended up in the same DAO - we only have 3
main Column Families that represent about 10 logical entities.

So we have now moved to a Command pattern where the mutations are encapsulated within a command
which can be used with other commands if need be - though we haven't found a need to just
yet.

Anthony




On 27/07/2011, at 08:15 AM, Selcuk Bozdag wrote:

> Hi,
> 
> The question I am asking is a bit about the design of a data access
> objects layer on top of a cassandra datastore.
> 
> I had a look at project Kundera which basically implies JPA approach
> by creating POJOs and mapping them through annotations. Looks
> promising but what if I would like to have new columns inside the data
> store(i.e. an attribute of a pojo class) without changing the
> codebase? How could I achieve such an extensiblity on the DAO layer?
> What would be the most relevant design pattern?
> 
> Please do not take the question regarding Kundera, it was just an
> example. The eventual design should let me CRUD POJOs while gaining an
> ability to be extended.
> 
> Regards,
> 
> Selcuk


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