[HIVE-9618] Deduplicate RS keys for ptf/windowing

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Component/s: PTF-Windowing
• Assignee: Navis Ryu
• Reporter: Navis Ryu
• Created: 09/Feb/15 07:57
• Updated: 18/May/15 19:52
• Resolved: 12/Feb/15 16:59

Description

Currently, partition spec containing same column for partition-by and order-by makes duplicated key column for RS. For example,

explain
select p_mfgr, p_name, p_size, 
rank() over (partition by p_mfgr order by p_name) as r, 
dense_rank() over (partition by p_mfgr order by p_name) as dr, 
sum(p_retailprice) over (partition by p_mfgr order by p_name rows between unbounded preceding and current row)  as s1
from noop(on noopwithmap(on noop(on part 
partition by p_mfgr 
order by p_mfgr, p_name
)))

"partition by p_mfgr order by p_mfgr, p_name" makes duplicated key columns like below

Reduce Output Operator
    key expressions: p_mfgr (type: string), p_mfgr (type: string), p_name (type: string)
    sort order: +++
    Map-reduce partition columns: p_mfgr (type: string)
    value expressions: p_size (type: int), p_retailprice (type: double)