[HIVE-4244] Make string dictionaries adaptive in ORC

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: File Formats
• Assignee: Kevin Wilfong
• Reporter: Owen O'Malley
• Created: 28/Mar/13 15:38
• Updated: 17/May/13 16:41

Description

The ORC writer should adaptively switch between dictionary and direct encoding. I'd propose looking at the first 100,000 values in each column and decide whether there is sufficient loading in the dictionary to use dictionary encoding.

Sub-Tasks

• ORC Turn off dictionary encoding when number of distinct keys is greater than threshold: Closed