Hi, this would indeed be much appreciated by a lot of people. There is this issue, existing about this subject
https://issues.apache.org/jira/browse/CASSANDRA-4914 Maybe could you help commiters there. Hope this will be usefull to you. Please let us know when you find a way to do these operations. Cheers. 2013/12/18 Brian O'Neill <b...@alumni.brown.edu> > We are seeking to replace Acunu in our technology stack / platform. It is > the only component in our stack that is not open source. > > In preparation, over the last few weeks I’ve migrated Virgil to CQL. The > vision is that Virgil could receive a REST request to upsert/delete data > (hierarchical JSON to support collections). Virgil would lookup the > dimensions/aggregations for that table, add the key to the pertinent > dimensional tables (e.g. DISTINCT), incorporate values into aggregations > (e.g. SUMs) and increment/decrement relevant counters (COUNT). (using > additional CF’s) > > This seems straight-forward, but appears to require a read-before-write. > (e.g. read the current value of a SUM, incorporate the new value, then use > the lightweight transactions of C* 2.0 to conditionally update the value.) > > Before I go down this path, I was wondering if anyone is designing/working > on the same, perhaps at a lower level? (CQL?) > > Is there any intent to support aggregations/filters (COUNT, SUM, DISTINCT, > etc) at the CQL level? If so, is there a preliminary design? > > I can see a lower-level approach, which would leverage the commit logs > (and mem/sstables) and perform the aggregation during read-operations (and > flush/compaction). > > thoughts? i'm open to all ideas. > > -brian > -- > Brian ONeill > Chief Architect, Health Market Science (http://healthmarketscience.com) > mobile:215.588.6024 > blog: http://brianoneill.blogspot.com/ > twitter: @boneill42 >
