[HIVE-8151] Dynamic partition sort optimization inserts record wrongly to partition when used with GroupBy

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.13.1, 0.14.0
• Fix Version/s: 0.14.0
• Release Note: Added config changes to https://cwiki.apache.org/confluence/display/Hive/Configuration+Properties
• Assignee: Prasanth Jayachandran
• Reporter: Prasanth Jayachandran
• Created: 16/Sep/14 22:27
• Updated: 13/Nov/14 19:43
• Resolved: 02/Oct/14 02:00

Description

HIVE-6455 added dynamic partition sort optimization. It added startGroup() method to FileSink operator to look for changes in reduce key for creating partition directories. This method however is not reliable as the key called with startGroup() is different from the key called with processOp(). startGroup() is called with newly changed key whereas processOp() is called with previously aggregated key. This will result in processOp() writing the last row of previous group as the first row of next group. This happens only when used with group by operator.

The fix is to not rely on startGroup() and do the partition directory creation in processOp() itself.

Issue Links

• is related to: HIVE-6455 Scalable dynamic partitioning and bucketing optimization
• links to: Review Board