On Thu, 10 Jul 2025 17:18:34 -0700 yun zou <yunzou.colost...@gmail.com> wrote: > > I think the point was raised previously that hard-coded names were > > preferred but I don't recall if that was when we were still calling this > > DayTime? > > I believe the main concern around naming is focused on whether to > use *"Duration"* or *"Interval"*, rather than the inclusion of *"Nano"* in > the type name. > > As for the parameterized time unit, the primary issue seems to be that > the *physical type size would vary depending on the unit* — for example, > using int32 for milliseconds and int64 for microseconds. However, it sounds > like the proposal is to use the same physical type, the unit is just used to > indicate the type name.
Certainly the latter, IMHO. > > I do think it's reasonable to parameterize `TimeUnit` > > for consistency and future proofing but for now we should say it only > > supports Nanoseconds > > It feels a bit odd to introduce a parameter when it currently only supports > a single value. > An alternative could be to start with a concrete type like *NanoDuration*, > and if future > requirements arise, we can consider adding new logical types such as > *MicroDuration*, etc. > The disadvantage is that the number of logical type definitions will > increase along with the units > we want to support, but I doubt there will be a lot. The Arrow format supports 64-bit durations of seconds, milliseconds, microseconds and nanoseconds. It would make sense for Parquet to roundtrip these types IMHO. Regards Antoine.
