Hi Val, Our proposal does not overlap with IEP-54 <https://cwiki.apache.org/confluence/display/IGNITE/IEP-54%3A+Schema-first+Approach>, which proposes changing Ignite date storage format. Our proposal is enhancing Ignite to handle .NET dates in a truly portable way instead of requiring the application developers to repeat this task every time:
- Write .NET dates as Ignite dates (today .NET dates are written as generic Ignite objects) - Convert Local .NET dates to UTC inside Ignite and to it using Java calendars. вт, 3 нояб. 2020 г. в 11:10, Valentin Kulichenko < valentin.kuliche...@gmail.com>: > Hi Alexey, > > The IEP-54 [1] describes the data layout proposed for Ignite 3.0, it > includes various date/time types. Can you please take a look and check if > this addresses your concerns? We can then discuss further if needed. > > > https://cwiki.apache.org/confluence/display/IGNITE/IEP-54%3A+Schema-first+Approach > > -Val > > On Tue, Nov 3, 2020 at 12:05 AM Alexey Kukushkin < > kukushkinale...@gmail.com> > wrote: > > > Pavel, > > > > We propose changing public API so this is for Ignite 3.0. > > > > Thanks! > > > > вт, 3 нояб. 2020 г. в 02:17, Pavel Tupitsyn <ptupit...@apache.org>: > > > > > Alexey, > > > > > > Just to clarify before we start the discussion: > > > this proposal seems to introduce some breaking changes, so we are > talking > > > about Ignite 3.0, correct? > > > > > > Pavel > > > > > > On Tue, Nov 3, 2020 at 12:13 AM Alexey Kukushkin < > > > kukushkinale...@gmail.com> > > > wrote: > > > > > > > Igniters, > > > > > > > > What do you think about changing .NET API to read/write portable > dates > > by > > > > default and making that really portable? > > > > > > > > *The Problem* > > > > Presently .NET API writes dates as composite Ignite objects. Only > .NET > > > > clients can read such dates: any other client (JDBC, Java, etc) does > > not > > > > understand it without custom deserialization. > > > > > > > > It is still possible to configure .NET serialization to write dates > as > > > > Ignite dates - see DateTime Serialization note > > > > < > > > > > > > > > > https://ignite.apache.org/docs/latest/net-specific/net-platform-interoperability#types-compatibility > > > > >. > > > > But then Ignite accepts only UTC dates, requiring the application > > > > developers to convert local dates to UTC dates and back. This task is > > not > > > > trivial: DateTime.ToUniversalTime > > > > < > > > > > > > > > > https://docs.microsoft.com/en-us/dotnet/api/system.datetime.touniversaltime?view=netcore-3.1 > > > > > > > > > uses > > > > calendars different from Java (and the .NET calendars are the invalid > > > ones > > > > - especially for pre-1990 dates). > > > > > > > > The motivation for the current default behavior was probably the > desire > > > to > > > > keep the Time Zone information: Ignite dates do not store time zones. > > > > > > > > In our experience interoperability is more important than storing > time > > > zone > > > > info. > > > > > > > > *The Proposal* > > > > > > > > 1. Always write .NET dates as portable Ignite dates: get rid of > the > > > > BinaryReflectiveSerializer.ForceTimestamp flag that currently > > triggers > > > > this > > > > behavior. > > > > - We could still keep the ForceTimestamp flag if saving .NET > > dates > > > as > > > > transparent objects seems a useful case. We do not think it is > > > > useful. > > > > 2. Automatically convert Local dates to UTC and back *inside* > > > > Ignite.NET. > > > > - In this case we lose the DateTime.Kind of UTC dates: we > write a > > > UTC > > > > date but we would read a Local date since Ignite would always > > > > convert UTC > > > > to Local when reading. > > > > We could add a UtcDate date flag to QuerySqlFieldAttribute > > > > and BinaryReflectiveSerializer to control the deserialization > > > > behavior if > > > > keeping dates in UTC format use case seems important. > > > > 3. Use NodaTime <https://nodatime.org/> for UTC<->Local > > conversions. > > > > Noda time uses Java calendars making the conversion truely > portable. > > > > > > > > *The Benefits* > > > > > > > > 1. We think portable dates are much more important than storing > time > > > > zone info. Why do we store time zones for every date on the server > > > > anyway? > > > > Time zone is client-side info. > > > > 2. Simpler application code: no more manual configuration to > trigger > > > the > > > > portable behavior. > > > > 3. Non-trivial code to make the truly portable UTC<->Local > > conversion > > > is > > > > implemented once inside Ignite instead of having every Ignite.NET > > > > application implementing it. > > > > > > > > Thank you! > > > > > > > > -- > > > > Best regards, > > > > Alexey > > > > > > > > > > > > > -- > > Best regards, > > Alexey > > > -- Best regards, Alexey
