Teddy Choi created HIVE-20873:
---------------------------------
Summary: Use Murmur hash for VectorHashKeyWrapperTwoLong to reduce
hash collision
Key: HIVE-20873
URL: https://issues.apache.org/jira/browse/HIVE-20873
Project: Hive
Issue Type: Improvement
Reporter: Teddy Choi
Assignee: Teddy Choi
VectorHashKeyWrapperTwoLong is implemented with few bit shift operators and XOR
operators for short computation time, but more hash collision. Group by
operations become very slow on large data sets. It needs Murmur hash or a
better hash function for less hash collision.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
