[IMPALA-13119] CostingSegment.java is initialized with wrong cost

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 4.4.0
• Fix Version/s: Impala 4.5.0, Impala 4.4.1
• Component/s: Frontend
• Target Version: Impala 4.5.0
• Epic Color: ghx-label-9
• Assignee: Riza Suminto
• Reporter: Riza Suminto
• Created: 30/May/24 21:50
• Updated: 14/Aug/24 01:01
• Resolved: 06/Jun/24 03:02

Description

CostingSegment.java has two public constructor: one accept PlanNode, while the other accept DataSink as parameter. Both call appendCost method, which sum the additionalCost with the segment's current cost_.

However, if cost_ were ProcessingCost.zero(), it can mistakenly setNumRowToConsume to 0.

https://github.com/apache/impala/blob/master/fe/src/main/java/org/apache/impala/planner/CostingSegment.java#L114 

The public constructor should just initialize cost_ with ProcessingCost from PlanNode or DataSink from constructor.