Hi, Timo.
As far as I know, table function should work with `lateral` keyword, it
means users can not use the following statement to read the results?
```
SELECT * FROM read_metadata('<path-to-file>')
```
Best,
Shengkai
Gabor Somogyi <gabor.g.somo...@gmail.com> 于2025年3月28日周五 16:18写道：
> Hi Timo,
>
> Thanks for the help!
> Your comment is fair and shows the proper direction in the mentioned FLIP.
>
> BR,
> G
>
>
> On Fri, Mar 28, 2025 at 8:36 AM Gyula Fóra <gyula.f...@gmail.com> wrote:
>
> > That's a very good point, I let Gabor and Shengkai follow up on that
> > suggestion :)
> >
> > Gyula
> >
> > On Fri, Mar 28, 2025 at 8:30 AM Timo Walther <twal...@apache.org> wrote:
> >
> > > Hi Gyula,
> > >
> > > if I understand the discussion correctly, you want to use a PTF without
> > > table arguments to return a table (read from savepoint metadata)? If
> > > this is the case, you don't need a PTF for it. A regular table function
> > > can also do the job. IIRC we support TVF with constant args.
> > >
> > > Cheers,
> > > Timo
> > >
> > > On 28.03.25 08:10, Gyula Fóra wrote:
> > > > Hi Timo!
> > > >
> > > > Thanks for the answers.
> > > >
> > > > Just to give some context here is this thread:
> > > > https://lists.apache.org/thread/08jwrocqyk1q82lnfdldhnyb79m496lp
> > > >
> > > > We were considering a PTF like state_metadata("checkpointpath") to
> > > create a
> > > > table with the available state metadata instead of creating a custom
> > > > connector for reading the metadata. Our thinking was this could
> > > completely
> > > > replace the need for a new connector.
> > > >
> > > > But this would only make sense if state_metadata("checkpointpath")
> > could
> > > > work as a proper table, such as we can make batch operations on it as
> > > well.
> > > >
> > > > Cheers,
> > > > Gyula
> > > >
> > > > On Fri, Mar 28, 2025 at 7:39 AM Timo Walther <twal...@apache.org>
> > wrote:
> > > >
> > > >> Hi Gabor,
> > > >>
> > > >> great that you already try out PTFs. I'm in the process of writing
> > > >> documentation for it. Including a list of limitations.
> > > >>
> > > >> Please note that PTF won't be support in batch mode in the first
> > phase.
> > > >> For stateful PTFs we would need to use a batch state backend and
> also
> > > >> other code paths around time need to be adjusted.
> > > >>
> > > >> Cheers,
> > > >> Timo
> > > >>
> > > >>
> > > >> On 28.03.25 03:31, Shengkai Fang wrote:
> > > >>> I think it is by design. You can read the FLIP, it says:
> > > >>>
> > > >>> *Time Semantics*:
> > > >>>
> > > >>> -
> > > >>>
> > > >>> PTFs support event-time semantics only.
> > > >>> -
> > > >>>
> > > >>> Processing-time doesn’t go well with batch mode and thus a
> > unified
> > > >> API
> > > >>> should built on event-time.
> > > >>> The proposed onWatermark timers allow for making processing
> > > >> nevertheless
> > > >>> and key-independent. An onWatermark should cover most
> processing
> > > >> time use
> > > >>> cases.
> > > >>>
> > > >>>
> > > >>> But I think if the PTF doesn't implement the `onTime` method, it
> > means
> > > >> the
> > > >>> function doesn't care about the time. In this case, we can just
> > > >>> convert directly in batch mode.
> > > >>>
> > > >>> Best,
> > > >>> Shengkai
> > > >>>
> > > >>> Gabor Somogyi <gabor.g.somo...@gmail.com> 于2025年3月28日周五 00:25写道：
> > > >>>
> > > >>>> Hi All,
> > > >>>>
> > > >>>> Seems like the process table function scan operation is not
> > supported
> > > in
> > > >>>> batch mode.
> > > >>>> Steps to repro [1] which gives the following exception:
> > > >>>>
> > > >>>> Caused by: org.apache.flink.table.api.TableException: Unsupported
> > > >> function
> > > >>>> for scan:PROCESS_TABLE
> > > >>>>
> > > >>>> Is this something which is planned?
> > > >>>>
> > > >>>> [1]
> > > >>>>
> > > >>>>
> > > >>
> > >
> >
> https://github.com/gaborgsomogyi/flink/commit/494b297082de718eae16e4e555ed58cefa404676
> > > >>>>
> > > >>>> BR,
> > > >>>> G
> > > >>>>
> > > >>>
> > > >>
> > > >>
> > > >
> > >
> > >
> >
>
