[SQL DDL] How to extract timestamps from Kafka message's metadata

[Dongwon Kim]

Hi,

I'm working on a Kafka topic where timestamps are not shown in the message
body, instead in the message's metadata.

I want to declare a table from the topic with DDL but "rowtime_column_name"
in the below definition seems to accept only existing columns.

> WATERMARK FOR rowtime_column_name AS watermark_strategy_expression.


Can I define watermarks in this situation where timestamps are shown only
in the metadata?

Thanks,

Dongwon