incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Olivier Mallassi <omalla...@octo.com>
Subject trying to make my ideas clear about partionning...
Date Mon, 10 May 2010 11:17:11 GMT
Hi all,

I am trying to make my ideas clear about how the partioning works in
Cassandra.

Here is what I understood, pease correct me if I am wrong.

- Row key are partitionned based on the partitionning strategy you choose
(randon, order preserving, custom if you implemented the IPartioner
interface). One partionning strategy is defined per cluster (in fact for
each node of the cluster but the confifguration should be the sames so...)
Order Preserving Partionning is better for range queries because the key are
stored in a sequential way so when selecting a range of keys, you hit less
nodes than with the RandomPartitioner.

- Once this first partitioning is done, a second one is done based on the
Column (or SuperColumn) name and the CompareWith you defined for the
ColumnFamily.

Am I right?
Am I wrong if I say that potentially the different columns of the same
ColumnFamily are stored on different nodes? So if I wanna read a complete
row, I hit several nodes.
Is there a way of controlling the way Column are stored?

Thanks for your help.

Oliv/

Mime
View raw message