COPY TO STDOUT Apache Arrow support

Hi,

would it be possible to add Apache Arrow streaming format to the copy
backend + frontend?
The use case is fetching (or storing) tens or hundreds of millions of rows
for client side data science purposes (Pandas, Apache Arrow compute
kernels, Parquet conversion etc). It looks like the serialization overhead
when using the postgresql wire format can be significant.

Best regards,
Adam Lippai