[
https://issues.apache.org/jira/browse/FLINK-24610?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Lyn Zhang updated FLINK-24610:
------------------------------
Description:
Flink sql projection not support reusing common expression in code generator.
For example the sql: SELECT split(a, '_'_)[1], split(a, '_'_)[2] FROM table.The
function split(a, '_') will be invoked 2 times per row data.
We can use CalcProgram.getExprList to generator each expression and
CalcProgram.getProjectList to eliminate common expression.
was:
Flink sql projection can not reuse common expression in code generator.
For example the sql: SELECT split(a, '_'_)[1], split(a, '_'_)[2] FROM table.
The function split(a, '_') will be invoked 2 times per row data. Eliminate
common expression by calcite.
> Flink projection common expression elimination
> ----------------------------------------------
>
> Key: FLINK-24610
> URL: https://issues.apache.org/jira/browse/FLINK-24610
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / Planner
> Reporter: Lyn Zhang
> Priority: Major
> Labels: pull-request-available
>
> Flink sql projection not support reusing common expression in code generator.
> For example the sql: SELECT split(a, '_'_)[1], split(a, '_'_)[2] FROM
> table.The function split(a, '_') will be invoked 2 times per row data.
> We can use CalcProgram.getExprList to generator each expression and
> CalcProgram.getProjectList to eliminate common expression.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
