[HIVE-22549] RS deduplication should not merge final aggregation without keys

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: Physical Optimizer
• Assignee: Jesús Camacho Rodríguez Assign to me
• Reporter: Jesús Camacho Rodríguez
• Created: 26/Nov/19 23:20
• Updated: 27/Feb/24 22:13
• Resolved: 07/Jan/20 18:20

Description

This may lead to performance degradation. For instance, this can happen for the following query:

set hive.support.concurrency=true;
set hive.txn.manager=org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;

EXPLAIN
CREATE TABLE x STORED AS ORC TBLPROPERTIES('transactional'='true') AS
SELECT * FROM SRC x CLUSTER BY x.key;

Issue Links

• is fixed by: HIVE-22538 RS deduplication does not always enforce hive.optimize.reducededuplication.min.reducer