Hi Timo,
Thanks for your proposal. It is a very pragmatic feature. Among all options
in the FLIP, option 3 is one I prefer too and I'd like to ask some
questions to understand your thoughts.
1. I did some research on pseudo columns, just out of curiosity, do you
know why most SQL systems do not need any prefix with their pseudo column?
2. Some platform providers will use ${variable_name} to define their own
configurations and allow them to be embedded into SQL scripts. Will there
be any conflict with option 3?
Best regards,
Jing
On Tue, Jul 25, 2023 at 7:00 PM Konstantin Knauf <kna...@apache.org> wrote:
> Hi Timo,
>
> this makes sense to me. Option 3 seems reasonable, too.
>
> Cheers,
>
> Konstantin
>
> Am Di., 25. Juli 2023 um 12:53 Uhr schrieb Timo Walther <
> twal...@apache.org
> >:
>
> > Hi everyone,
> >
> > I would like to start a discussion about introducing the concept of
> > "System Columns" in SQL and Table API.
> >
> > The subject sounds bigger than it actually is. Luckily, Flink SQL
> > already exposes the concept of metadata columns. And this proposal is
> > just a slight adjustment for how metadata columns can be used as system
> > columns.
> >
> > The biggest problem of metadata columns currently is that a catalog
> > implementation can't provide them by default because they would affect
> > `SELECT *` when adding another one.
> >
> > Looking forward to your feedback on FLIP-348:
> >
> >
> >
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-348%3A+Support+System+Columns+in+SQL+and+Table+API
> >
> > Thanks,
> > Timo
> >
>
>
> --
> https://twitter.com/snntrable
> https://github.com/knaufk
>
