I'm arrow Java there is a record level accesor facade called FieldReader. There is also a record level builder called ComplexWriter. Both allow arbitrary complex data to be worked with using method invocations. Won't be as efficient as a columnar algorithm but definitely much easier to get started. We use a heavily overloaded interface pattern to basically support dynamic typing. 

Example reader use
https://github.com/dremio/dremio-oss/blob/master/sabot/kernel/src/main/java/com/dremio/exec/vector/complex/fn/JsonWriter.java

Example builder use
https://github.com/dremio/dremio-oss/blob/master/sabot/kernel/src/main/java/com/dremio/exec/vector/complex/fn/JsonReader.java

On Fri, Aug 30, 2019, 8:14 PM Micah Kornfield <emkornfield@gmail.com> wrote:
Hi Simon,
A couple notes:
- Scalars are a C++ thing, There are ValueHolders in Java but i'm not sure what you want.
- Dremio has a JDBC adaptor [1] that might be worth looking at (or maybe porting pieces of it into Arrow).

Thanks,
Micah




On Fri, Aug 30, 2019 at 12:03 PM Simon Dumke <simon.dumke@ipp.mpg.de> wrote:
Hi Ben,

thanks for the suggestion, i'll loon into it!

Regards,
Simon

Am 30. August 2019 20:59:23 schrieb Ben Kietzman <ben.kietzman@rstudio.com>:

Hi Simon,

If you're interested in adding a record interface, the Scalar classes might be a good place to start. They represent a value from an array slot and it should be fairly straightforward to extract a table row as a StructScalar

On Fri, Aug 30, 2019 at 1:27 PM Wes McKinney <wesmckinn@gmail.com> wrote:
hi Simon -- I don't think there is any such Row accessor class in Java
but you are welcome to contribute one to the project. For performance
sensitive applications, using a record interface might not be the best
idea, but I can understand the convenience for some uses cases.

- Wes

On Fri, Aug 30, 2019 at 4:55 AM Simon Dumke <simon.dumke@ipp.mpg.de> wrote:
>
> Hi all,
>
>
>
>
> I did not find anything (and so: no definite answer) in the docs, so i
> thought to ask here:
>
>
>
>
> Does Arrow (and at this point my main concern is Arrow for java) support
> any type of concept that allows a "record level access" (so, a "row") to
> data in an Arrow RecordBatch or Table? I would have thougt that even in
> column-oriented analytics etc. this would be a common last step access
> pattern over many use cases, but i could not find any references to such a
> thing.
>
>
>
>
> Thanks and kind regards,
> Simon
>
>