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
