HIVE-5325: Implement statistics providing ORC writer and reader interfaces
Review Request #14243 - Created Sept. 20, 2013 and updated
HIVE-5324 adds new interfaces that can be implemented by ORC reader/writer to provide statistics. Writer provided statistics is used to update table/partition level statistics in metastore. Reader provided statistics can be used for reducer estimation, CBO etc. in the absence of metastore statistics.
ORC related unit and qfile tests are passing.