Given no objections, we'll go ahead and start implementing support for 256-bit decimals.
I'm considering setting up another branch to develop all the components so they can be merged to master atomically. Thanks, Micah On Tue, Jul 28, 2020 at 6:39 AM Wes McKinney <wesmck...@gmail.com> wrote: > Generally this sounds fine to me. At some point it would be good to > add 32-bit and 64-bit decimal support but this can be done in the > future. > > On Tue, Jul 28, 2020 at 7:28 AM Fan Liya <liya.fa...@gmail.com> wrote: > > > > Hi Micah, > > > > Thanks for opening the discussion. > > I am aware of some scenarios where decimal requires more than 16 bytes, > so > > I think it would be beneficial to support this in Arrow. > > > > Best, > > Liya Fan > > > > > > On Tue, Jul 28, 2020 at 11:12 AM Micah Kornfield <emkornfi...@gmail.com> > > wrote: > > > > > Hi Arrow Dev, > > > ZetaSQL (Google's open source standard SQL library) recently > introduced a > > > BigNumeric [1] type which requires a 256 bit width to properly support > it. > > > I'd like to add support (possibly in collaboration with some of my > > > colleagues) to add support for 256 bit width Decimals in Arrow to > support a > > > type corresponding to BigNumeric. > > > > > > In past discussions on this, I don't think we established a minimum > bar for > > > supporting additional bit-widths within Arrow. > > > > > > I'd like to propose the following requirements: > > > 1. A vote agreeing on adding support for a new bitwidth (we can > discuss > > > any objections here). > > > 2. Support in Java and C++ for integration tests verifying the > ability to > > > round-trip the value. > > > 3. Support in Java for conversion to/from BigDecimal [2] > > > 4. Support in Python converting to/from Decimal [3] > > > > > > Is there anything else that people feel like is a requirement for basic > > > support of an additional bit width for Decimal's? > > > > > > Thanks, > > > Micah > > > > > > > > > [1] > > > > > > > https://github.com/google/zetasql/blob/1aefaa7c62fc7a50def879bb7c4225ec6974b7ef/zetasql/public/numeric_value.h#L486 > > > [2] > https://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html > > > [3] https://docs.python.org/3/library/decimal.html > > > >
