While it is possible to convert to IntLiteral or even probably to DateLiteral, presto mostly delegates to iceberg to do the proper conversion from LongLiteral, AFAIK (see https://github.com/prestosql/presto/blob/de97d1572d7da5570177627bd42fbb8b7fdd417e/presto-iceberg/src/main/java/io/prestosql/plugin/iceberg/ExpressionConverter.java#L167)
Thank you, Vlad On 2020/02/19 20:10:14, Ryan Blue <rb...@netflix.com.INVALID> wrote: > Can you describe the use case a bit more? What prevents you from using an > IntLiteral instead? > > On Wed, Feb 19, 2020 at 11:26 AM Vlad Rozov <vro...@apache.org> wrote: > > > Hi Ryan, > > > > Thank you for the detailed explanation. Yes, there is a use case in Presto > > for LongLiteral to DateLiteral conversion as it uses long and allows it to > > be converted/cast to Date. > > > > Thank you, > > > > Vlad > > > > On 2020/02/19 18:54:35, Ryan Blue <rb...@netflix.com.INVALID> wrote: > > > Originally, we didn't allow int to date or long to timestamp, but we > > added > > > those to support expression conversion from Spark. It's much easier to > > > allow the LongLiteral created from a Spark timestamp expression directly > > to > > > a TimestampLiteral than to convert to an equivalent timestamp string > > > because the internal representation in Spark and Iceberg are the same. > > The > > > conversion from long to date was never really needed by this path, so we > > > probably didn't add it. Iceberg is fairly strict with allowed conversions > > > to date and timestamp because the validation we can apply is still very > > > permissive. > > > > > > I think it's fine to add long to date if there is a need, but otherwise > > I'd > > > leave it as it is. Do you have a use case for this? > > > > > > On Tue, Feb 18, 2020 at 3:19 PM Vlad Rozov <vro...@apache.org> wrote: > > > > > > > Hi, > > > > > > > > What is the reason iceberg does not allow LongLiteral to DateLiteral > > > > conversion while allowing LongLiteral to IntegerLiteral and > > IntegerLiteral > > > > to DateLiteral? Should not direct conversion from LongLiteral to > > > > DateLiteral be allowed when LongLiteral represents values in a proper > > range? > > > > > > > > Thank you, > > > > > > > > Vlad > > > > > > > > > > > > -- > > > Ryan Blue > > > Software Engineer > > > Netflix > > > > > > > > -- > Ryan Blue > Software Engineer > Netflix >
