HIVE-7695 : hive stats issue when insert query is appending data into table (Ashutosh Chauhan via Prashanth J)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.14@1629074 13f79535-47bb-0310-9956-ffa450edef68
HIVE-8318 : Null Scan optimizer throws exception when no partitions are selected (Ashutosh Chauhan via Gunther Hagleitner)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.14@1629075 13f79535-47bb-0310-9956-ffa450edef68