I've put together a proposal describing changes to Hive's metastore and Thrift API to support statistics at the level of a column in a Hive table/partition. Please bear in mind that this proposal is a work in progress. The goal of the proposal is to obtain feedback from the community. Hence it would be great if you could comment on the proposal.
https://cwiki.apache.org/confluence/display/Hive/Column+Statistics+API Thanks, Shreepadma
