Thanks for the suggestion Sasha! Will give it a try. On Tue, Mar 21, 2023 at 12:30 PM Sasha Krassovsky <[email protected]> wrote:
> Hi Haocheng, > I agree that the Project node could be a good candidate for this. One of > the expressions that Project can take is called “cast”. In C++ you would do > something like > > Expression cast_expr = call(“cast”, my_column, > compute::CastOptions::Unsafe(uint32())); > > And pass that expression to your Project node. > > Hope this helps, > Sasha > > 21 марта 2023 г., в 09:10, Haocheng Liu <[email protected]> написал(а): > > > Hi, > > I have a use case that my reader node will read in POD types as int8_t, > int16_t, int32.t, etc from a bespoke format. Due to downstream > library requirements, I have to upcast *all* int8_t and int16_t columns > to int32_t. Based on my reading the Project node > <https://arrow.apache.org/docs/cpp/streaming_execution.html#project> looks > most promising for this type of workflow. > > I check the examples in source code and online documentation, to my best > knowledge they only cover how to apply predefined functions rather than > doing a type conversion. Can anyone guide what's the best practice here in > C++? > > Thanks. > > Best regards > Haocheng > > -- Best regards
