[
https://issues.apache.org/jira/browse/FLINK-39095?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
ASF GitHub Bot updated FLINK-39095:
-----------------------------------
Labels: enhancement pull-request-available table-planner usability (was:
enhancement table-planner usability)
> [SQL] Display ChangelogMode in Execution Plan for Streaming Queries
> -------------------------------------------------------------------
>
> Key: FLINK-39095
> URL: https://issues.apache.org/jira/browse/FLINK-39095
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / Planner
> Reporter: featzhang
> Priority: Minor
> Labels: enhancement, pull-request-available, table-planner,
> usability
>
> Currently, Flink's execution plan (ExecNode level) does not display the
> ChangelogMode information for streaming queries. This makes it difficult for
> users to understand:
> - Whether the stream is append-only
> - Whether it contains retractions (UPDATE_BEFORE, UPDATE_AFTER, DELETE)
> - The exact changelog semantics of each operator
> While the physical plan (StreamPhysicalRel) already supports displaying
> ChangelogMode via ExplainDetail.CHANGELOG_MODE, the execution plan (ExecNode)
> does not expose this information.
> This enhancement proposes to add ChangelogMode display to the execution plan
> output, making it more transparent for users to understand the streaming
> semantics.
> Motivation:
> Many users are confused about:
> 1. Whether their query produces append-only results or retract streams
> 2. Which operators introduce retractions
> 3. The changelog semantics of intermediate results
> This information is critical for:
> - Understanding query behavior
> - Performance tuning
> - Debugging unexpected results
> - Choosing appropriate sink connectors
> Proposed Changes:
> 1. Add a method to ExecNode interface or StreamExecNode to retrieve
> ChangelogMode
> 2. Modify ExecNodePlanDumper to display ChangelogMode information
> 3. Format: Display as "changelogMode=[I,UB,UA,D]" where:
> - I = INSERT
> - UB = UPDATE_BEFORE
> - UA = UPDATE_AFTER
> - D = DELETE
> Example Output:
> Before:
> ```
> Calc(select=[a, b])
> +- TableSourceScan(table=[[my_table]])
> ```
> After:
> ```
> Calc(select=[a, b], changelogMode=[I,UB,UA])
> +- TableSourceScan(table=[[my_table]], changelogMode=[I,UB,UA,D])
> ```
> Implementation Location:
> - ExecNode.java or StreamExecNode.java: Add getChangelogMode() method
> - ExecNodePlanDumper.java: Modify to display ChangelogMode in tree/DAG output
> - ExecNodeBase.java: Provide default implementation that derives from
> ModifyKindSetTrait and UpdateKindTrait
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
