Thanks Paul, If we make a CF Name_Address(name, address) rather than an index, we have to maintain it, once any change happens in ID_Address(*Id*, address) , Name_ID(*name*, id). Besides, it also occupies some space.
In contrast, if Name_Address(name, address) is just an index, we can redirect the query to ID_Address(*Id*, address) , Name_ID(*name*, id) without the cost of maintenance. Does it make sense? Alvin 2010/9/16 Rock, Paul <paul.r...@teamaol.com> > Alvin - assuming I understand what you're after correctly, why not make a > CF Name_Address(name, address). Modifying the Cassandra methods to do the > "join" you describe seems like overkill to me... > > -Paul > > On Sep 15, 2010, at 7:34 PM, Alvin UW wrote: > > Hello, > > I am going to build an index to join two CFs. > First, we see this index as a CF/SCF. The difference is I don't materialise > it. > Assume we have two tables: > ID_Address(*Id*, address) , Name_ID(*name*, id) > Then,the index is: Name_Address(*name*, address) > > When the application tries to query on Name_Address, the value of "name" is > given by the application. > I want to direct the read operation to Name_ID to get "Id" value, then go > to ID_Address to > get the "address" value by the "Id" value. So far, I consider only the read > operation. > By this way, the join query is transparent to the user. > > So I think I should find out which methods or classes are in charge of the > read operation in the above operation. > For example, the operation in cassandra CLI "get > Keyspace1.Standard2['jsmith']" calls exactly which methods > in the server side? > > I noted CassandraServer is used to listen to clients, and there are some > methods such as get(), get_slice(). > Is it the right place I can modify to implement my idea? > > Thanks. > > Alvin > > >
