Thanks Alkis, that is interesting data.

> We found that the reported numbers were not reproducible on AWS instances

I just updated the benchmark results[1] to include results from
AWS m6id.8xlarge instance (and they are indeed about 2x slower than when
run on my 2023 Mac laptop)

> You can find the summary of our findings in a separate tab in the
proposal document:

Thank you, these are interesting. Can you share instructions on how to
reproduce the reported numbers? I am interested to review the code used to
generate these results (esp the C++ thrift code)

Thanks
Andrew


[1]:
https://github.com/alamb/parquet_footer_parsing?tab=readme-ov-file#results-on-linux


On Fri, Oct 17, 2025 at 10:20 AM Alkis Evlogimenos
<[email protected]> wrote:

> Thank you Andrew for putting the code in open source so that we can repro
> it.
>
> We have run the rust benchmarks and also run the flatbuf proposal with our
> C++ thrift parser, the flatbuf footer with Thrift conversion, the
> flatbuf footer without Thrift conversion, and the flatbuf footer
> without Thrift conversion and without verification. You can find the
> summary of our findings in a separate tab in the proposal document:
>
> https://docs.google.com/document/d/1kZS_DM_J8n6NKff3vDQPD1Y4xyDdRceYFANUE0bOfb0/edit?tab=t.ve65qknb3sq1#heading=h.3uwb5liauf1s
>
> The TLDR is that flatbuf is 5x faster with the Thrift conversion vs the
> optimized Thrift parsing. It also remains faster than the Thrift parser
> even if the Thrift parser skips statistics. Furthermore if Thrift
> conversion is skipped, the speedup is 50x, and if verification is skipped
> it goes beyond 150x.
>
>
> On Tue, Sep 30, 2025 at 5:56 PM Andrew Lamb <[email protected]>
> wrote:
>
> > Hello,
> >
> > I did some benchmarking for the new parser[2] we are working on in
> > arrow-rs.
> >
> > This benchmark achieves nearly an order of magnitude improvement (7x)
> > parsing Parquet metadata with no changes to the Parquet format, by simply
> > writing a more efficient thrift decoder (which can also skip statistics).
> >
> > While we have not implemented a similar decoder in other languages such
> as
> > C/C++ or Java, given the similarities in the existing thrift libraries
> and
> > usage, we expect similar improvements are possible in those languages as
> > well.
> >
> > Here are some inline images:
> > [image: image.png]
> > [image: image.png]
> >
> >
> > You can find full details here [1]
> >
> > Andrew
> >
> >
> > [1]: https://github.com/alamb/parquet_footer_parsing
> > [2]: https://github.com/apache/arrow-rs/issues/5854
> >
> >
> > On Wed, Sep 24, 2025 at 5:59 PM Ed Seidl <[email protected]> wrote:
> >
> >> > Concerning Thrift optimization, while a 2-3x improvement might be
> >> > achievable, Flatbuffers are currently demonstrating a 10x improvement.
> >> > Andrew, do you have a more precise estimate for the speedup we could
> >> expect
> >> > in C++?
> >>
> >> Given my past experience on cuDF, I'd estimate about 2X there as well.
> >> cuDF has it's own metadata parser that I once benchmarked against the
> >> thrift generated parser.
> >>
> >> And I'd point out that beyond the initial 2X improvement, rolling your
> >> own parser frees you of having to parse out every structure in the
> metadata.
> >>
> >
>

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