[
https://issues.apache.org/jira/browse/FLINK-15004?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
godfrey he updated FLINK-15004:
-------------------------------
Description: Currently, blink planner will use default rowCount value
(defined in {{FlinkPreparingTableBase#DEFAULT_ROWCOUNT}} ) when the statistics
is unknown, and maybe choose one-phase Aggregate. The job will hang if the data
is skewed. So It's better to use two-phase Aggregate for execution stability if
the statistics is unknown. (was: Currently, blink planner will use default
rowCount value (defined in {{FlinkPreparingTableBase#DEFAULT_ROWCOUNT}} ) when
the statistics is unknown, and maybe choose {{HashJoin}} instead of
{{SortMergeJoin}}. The job will hang if the build side of {{HashJoin}} has huge
input size. So It's better to use {{SortMergeJoin}} for execution stability if
the statistics is unknown.)
> Choose two-phase Aggregate if the statistics is unknown
> -------------------------------------------------------
>
> Key: FLINK-15004
> URL: https://issues.apache.org/jira/browse/FLINK-15004
> Project: Flink
> Issue Type: Sub-task
> Components: Table SQL / Planner
> Affects Versions: 1.9.0, 1.9.1
> Reporter: godfrey he
> Assignee: godfrey he
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.10.0
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Currently, blink planner will use default rowCount value (defined in
> {{FlinkPreparingTableBase#DEFAULT_ROWCOUNT}} ) when the statistics is
> unknown, and maybe choose one-phase Aggregate. The job will hang if the data
> is skewed. So It's better to use two-phase Aggregate for execution stability
> if the statistics is unknown.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
