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!"
