[jira] [Commented] (FLINK-17868) Proctime in DDL can not work in batch mode

["Qingyue (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-17868?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17258187#comment-17258187 ] 

Qingyue commented on FLINK-17868:
---------------------------------

Hi [~jark] and [~lzljs3620320], I'm interested in this issue and want to have a try.

I came up with three possible solutions and listed the proposed and rejected alternatives and want to hear your opinions. Please correct me if I'm wrong.
h3. Proposed plan

Introduce a new rule and program to `FlinkBatchProgram` to rewrite `PROCTIME()` to `CURRENT_TIMESTAMP()` at planning phase.
h3. Alternative plans

1. Introduce `FlinkBatchProgram` to `FlinkRelTimeIndicatorProgram` (i.e. reuse `RelTimeIndicatorConveter`) and rewrite `PROCTIME ` to `PROCTIME_MATERIALIZE ` during planning phase.
 * Pro: translated batch plan is same as stream plan `Calc(select=[a, c, PROCTIME_MATERIALIZE(PROCTIME()) AS EXPR$2])`.

 * Con: `PROCTIME_MATERIALIZE ` is transformed to process function of`AbstractProcessStreamOperator`, which introduces `ctx.timerService()`. While `BatchExecCalc` uses `TableStreamOperator` as operator base class, it causes the generated code to fail to compile. To solve this, either modify the codegen logic to avoid using `timerService` for batch or move `ctx` from `AbstractProcessStreamOperator` to its parent `TableStreamOperator`.

2. We don't change the current plan(i.e., `Calc(select=[a, c, PROCTIME() AS EXPR$2]` remains unchanged). Instead, we modify the codegen logic at the transformation phase. We add a check on `PROCTIME` when `ExprCodeGenerator#generateCallExpression` is called, and if it's a batch transformation, we generate `currentTimestamp` directly.
 * Pro: the modified scope is limited to a minimum.

 * Con: It may not be proper to distinguish stream vs. batch during the transformation phase.

 

Thanks, Qingyue.

> Proctime in DDL can not work in batch mode
> ------------------------------------------
>
>                 Key: FLINK-17868
>                 URL: https://issues.apache.org/jira/browse/FLINK-17868
>             Project: Flink
>          Issue Type: Bug
>          Components: Table SQL / Planner
>            Reporter: Jingsong Lee
>            Priority: Major
>              Labels: sprint
>             Fix For: 1.13.0
>
>
> The data of this proctime column will be all null. Should same to current timestamp.



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