[HIVE-9757] LLAP: Reuse string dictionaries per column per stripe when processing row groups

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: llap
• Fix Version/s: llap
• Assignee: Prasanth Jayachandran
• Reporter: Prasanth Jayachandran
• Created: 23/Feb/15 23:04
• Updated: 17/Feb/16 01:33
• Resolved: 02/Mar/15 21:23

Description

Dictionary streams are cached by low level cache. When creating column vectors from streams we create dictionary for every row group that we process. We should add per query cache to cache the deserialized representation of dictionary per stripe per column.