+1 to rename ANY. I don't have strong opinion on the new name. I think "OPAQUE" is fine, because it is introduced in IBM Informix and Oracle. In Informix, it says [1]:
"An opaque data type is fully encapsulated; the database server does not know about the internal format of an opaque data type. Therefore, the database server cannot make assumptions about how to access a column having an opaque data type. The database developer defines a data structure that holds the opaque-type information and support functions that tell the database server how to access this data structure." So, I think "opaque" is fine here. Another option is "RAW" which is introduced by Oracle [2] represents data that is not to be interpreted by system . Best, Jark [1]: https://www.ibm.com/support/knowledgecenter/en/SSGU8G_11.70.0/com.ibm.esqlc.doc/ids_esqlc_0357.htm [2]: https://docs.oracle.com/cd/B28359_01/server.111/b28318/datatype.htm#CNCPT613 On Mon, 21 Oct 2019 at 15:49, 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!" > >
