[HIVE-2845] Add support for index joins in Hive

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Indexing, Query Processor
• Labels: indexing joins performance
• Assignee: Unassigned
• Reporter: Namit Jain
• Created: 07/Mar/12 01:30
• Updated: 19/Aug/12 21:46

Description

Hive supports indexes, which are used for filters currently.

It would be very useful to add support for index-based joins in Hive.
If 2 tables A and B are being joined, and an index exists on the join key of A,
B can be scanned (by the mappers), and for each row in B, a lookup for the corresponding row in A can be performed.
This can be very useful for some usecases.