Since there hasn't been other movement on this, we need to disable writing LZ4-compressed files until this can be investigated more thoroughly. If someone wants to submit a patch that would be helpful otherwise I can take a look in the next couple days
On Thu, Jul 2, 2020 at 12:50 PM Antoine Pitrou <anto...@python.org> wrote: > > > Well, it depends how important speed is, but LZ4 has extremely fast > decompression, even compared to Snappy: > https://github.com/lz4/lz4#benchmarks > > Regards > > Antoine. > > > Le 02/07/2020 à 19:47, Christian Hudon a écrit : > > At least for us, the advantages of Parquet are speed and interoperability > > in the context of longer-term data storage, so I would tend to say > > "reasonably conservative". > > > > Le mer. 1 juill. 2020, à 09 h 32, Antoine Pitrou <solip...@pitrou.net> a > > écrit : > > > >> > >> I don't have a sense of how conservative Parquet users generally are. > >> Is it worth adding a LZ4_FRAMED compression option in the Parquet > >> format, or would people just not use it? > >> > >> Regards > >> > >> Antoine. > >> > >> > >> On Tue, 30 Jun 2020 14:33:17 +0200 > >> "Uwe L. Korn" <uw...@xhochy.com> wrote: > >>> I'm also in favor of disabling support for now. Having to deal with > >> broken files or the detection of various incompatible implementations in > >> the long-term will harm more than not supporting LZ4 for a while. Snappy is > >> generally more used than LZ4 in this category as it has been available > >> since the inception of Parquet and thus should be considered as a viable > >> alternative. > >>> > >>> Cheers > >>> Uwe > >>> > >>> On Mon, Jun 29, 2020, at 11:48 PM, Wes McKinney wrote: > >>>> On Thu, Jun 25, 2020 at 3:31 AM Antoine Pitrou <anto...@python.org> > >> wrote: > >>>>> > >>>>> > >>>>> Le 25/06/2020 à 00:02, Wes McKinney a écrit : > >>>>>> hi folks, > >>>>>> > >>>>>> (cross-posting to dev@arrow and dev@parquet since there are > >>>>>> stakeholders in both places) > >>>>>> > >>>>>> It seems there are still problems at least with the C++ > >> implementation > >>>>>> of LZ4 compression in Parquet files > >>>>>> > >>>>>> https://issues.apache.org/jira/browse/PARQUET-1241 > >>>>>> https://issues.apache.org/jira/browse/PARQUET-1878 > >>>>> > >>>>> I don't have any particular opinion on how to solve the LZ4 issue, > >> but > >>>>> I'd like to mention that LZ4 and ZStandard are the two most efficient > >>>>> compression algorithms available, and they span different parts of > >> the > >>>>> speed/compression spectrum, so it would be a pity to disable one of > >> them. > >>>> > >>>> It's true, however I think it's worse to write LZ4-compressed files > >>>> that cannot be read by other Parquet implementations (if that's what's > >>>> happening as I understand it?). If we are indeed shipping something > >>>> broken then we either should fix it or disable it until it can be > >>>> fixed. > >>>> > >>>>> Regards > >>>>> > >>>>> Antoine. > >>>> > >>> > >> > >> > >> > >> > >
