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https://issues.apache.org/jira/browse/FLINK-7337?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16111030#comment-16111030
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Fabian Hueske commented on FLINK-7337:
--------------------------------------

We would of course still have a logical and a physical schema. The logical 
schema is Calcite's {{RelDataType}} and the physical schema is based on Flink's 
{{TypeInformation}}.
However, both would be have the same schema and we do not need a special 
translation that "filters" out time indicator fields and keeps track of their 
positions. Hence, we might be able to remove the {{RowSchema}} class (or keep 
it but significantly simplify the logic).

Time indicator fields would be defined and identified as before. So we would 
still use {{.rowtime}} and {{.proctime}} when converting a {{DataStream}} into 
a {{Table}} and the equivalent interfaces for {{TableSources}}. Fields which 
are declared as {{rowtime}} (or {{proctime}}) will have a special time 
indicator type (as right now). Any expressions that is evaluated on such a 
field results in a regular timestamp type, i.e., the resulting value cannot be 
used as a time indicator. AFAIK, the current approach uses similar checks.

So essentially, many things (including the API) remain as they are. We are 
"only" changing the internal representation of timestamp attributes.


> Refactor handling of time indicator attributes
> ----------------------------------------------
>
>                 Key: FLINK-7337
>                 URL: https://issues.apache.org/jira/browse/FLINK-7337
>             Project: Flink
>          Issue Type: Improvement
>          Components: Table API & SQL
>    Affects Versions: 1.4.0
>            Reporter: Fabian Hueske
>            Assignee: Fabian Hueske
>
> After a [discussion on the dev mailing 
> list|https://lists.apache.org/thread.html/735d55f9022df8ff73566a9f1553e14be94f8443986ad46559b35869@%3Cdev.flink.apache.org%3E]
>  I propose the following changes to the current handling of time indicator 
> attributes:
> * Remove the separation of logical and physical row type.
> ** Hold the event-time timestamp as regular Long field in Row
> ** Represent the processing-time indicator type as a null-valued field in Row 
> (1 bit overhead)
> * Remove materialization of event-time timestamps because timestamp is 
> already accessible in Row.
> * Add {{ProcessFunction}} to set timestamp into the timestamp field of a 
> {{StreamRecord}}.



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