Hi, IMHO, `UNKNOWN` does not fully reflects the situation here, because the types are actually “known” to users, and users just want to leave them out of Flink type system.
+1 for `RAW`, for it's more intuitive than `OPAQUE`. Best, Paul Lam > 在 2019年10月21日，16:43，Kurt Young <ykt...@gmail.com> 写道： > > OPAQUE seems to be a little bit advanced to a lot non-english > speakers (including me). I think Xuefu raised a good alternative: > UNKNOWN. What do you think about it? > > Best, > Kurt > > > On Mon, Oct 21, 2019 at 3:49 PM Aljoscha Krettek <aljos...@apache.org> > wrote: > >> I prefer OPAQUE compared to ANY because any is often the root object in an >> object hierarchy and would indicate to users the wrong thing. >> >> Aljoscha >> >>> On 18. Oct 2019, at 18:41, Xuefu Z <usxu...@gmail.com> wrote: >>> >>> Thanks to Timo for bringing up an interesting topic. >>> >>> Personally, "OPAQUE" doesn't seem very intuitive with respect to types. >> (It >>> suits pretty well to glasses, thought. :)) Anyway, could we just use >>> "UNKNOWN", which is more explicit and true reflects its nature? >>> >>> Thanks, >>> Xuefu >>> >>> >>> On Fri, Oct 18, 2019 at 7:51 AM Timo Walther <twal...@apache.org> wrote: >>> >>>> Hi everyone, >>>> >>>> Stephan pointed out that our naming of a generic/blackbox/opaque type in >>>> SQL might be not intuitive for users. As the term ANY rather describes a >>>> "super-class of all types" which is not the case in our type system. Our >>>> current ANY type stands for a type that is just a blackbox within SQL, >>>> serialized by some custom serializer, that can only be modified within >>>> UDFs. >>>> >>>> I also gathered feedback from a training instructor and native English >>>> speaker (David in CC) where I received the following: >>>> >>>> "The way I’m thinking about this is this: there’s a concept here that >>>> people have to become aware of, which is that Flink SQL is able to >>>> operate generically on opaquely typed things — and folks need to be able >>>> to connect what they see in code examples, etc. with this concept (which >>>> they may be unaware of initially). >>>> I feel like ANY misses the mark a little bit, but isn’t particularly >>>> bad. I do worry that it may cause some confusion about its purpose and >>>> power. I think OPAQUE would more clearly express what’s going on." >>>> >>>> Also resources like Wikipedia [1] show that this terminology is common: >>>> >>>> "a data type whose concrete data structure is not defined [...] its >>>> values can only be manipulated by calling subroutines that have access >>>> to the missing information" >>>> >>>> I would therefore vote for refactoring the type name because it is not >>>> used much yet. >>>> >>>> Implications are: >>>> >>>> - a new parser keyword "OPAQUE" and changed SQL parser >>>> >>>> - changes for logical type root, logical type visitors, and their usages >>>> >>>> What do you think? >>>> >>>> Thanks, >>>> >>>> Timo >>>> >>>> [1] https://en.wikipedia.org/wiki/Opaque_data_type >>>> >>>> >>>> >>> >>> -- >>> Xuefu Zhang >>> >>> "In Honey We Trust!" >> >>
