Hi Jingsong, Thanks for your input. I'd prefer to keep Hive syntax to a separate parser, because 1) Supporting both Hive and Flink syntax in one parser makes the grammar complicated and less efficient, e.g. we may need a bigger LOOKAHEAD value to resolve conflicts. 2) It can be difficult to add new features to a syntax without interfering with the other one. 3) It'll be more difficult to turn off Hive syntax when Hive dialect is not used. The separate parser only requires minimum change in the planner, which I think is acceptable compared to the benefits it brings us.
On Thu, Apr 9, 2020 at 10:42 PM Jingsong Li <jingsongl...@gmail.com> wrote: > Thanks Rui for diving. > > +1 for this proposal. > > There are still lots of people who love Hive SQL. > And I have seen some people support HQL on presto. Presto, as a famous > computing engine, also supports ANSI SQL as we do. This is quite different > from HQL. > > Do you think we must need import `FlinkHiveSqlParserImpl`? This will bother > planner code, if possible, I think it is better to keep dialect things in > sql-parer. > What do you think? > > Best, > Jingsong Lee > > On Thu, Apr 9, 2020 at 3:56 PM Rui Li <lirui.fu...@gmail.com> wrote: > > > Hi Kurt, > > > > Thanks for the feedback and that's a good idea. I have updated the FLIP > and > > added tables in the "Limited Scope" section to list the supported and > > unsupported features. Please have a look and let me know if that makes > > sense. Thanks. > > > > On Wed, Apr 8, 2020 at 2:19 PM Kurt Young <ykt...@gmail.com> wrote: > > > > > Hi Rui, > > > > > > Thanks for bringing up this discussion and it makes sense to me though > i > > > have one comment about the FLIP. > > > There are a few places in the design document saying some features will > > not > > > be supported or not included in > > > this FLIP, but I don't get what will be supported exactly. I can > imagine > > > other users will also have such confusion. > > > Could you add a table or a list of syntax which will be supported? > > > > > > Best, > > > Kurt > > > > > > > > > On Wed, Apr 1, 2020 at 4:24 PM Rui Li <li...@apache.org> wrote: > > > > > > > Hi devs, > > > > > > > > I'd like to start a discussion about bringing DDL & DML compatibility > > for > > > > Hive connector. The proposal mainly aims to implement more DDLs for > > Hive > > > > connector and allow users to write Hive syntax when using the Hive > > > dialect. > > > > Hopefully this will make it easier for users to migrate to Flink, > with > > > > fewer SQL statements that need to be changed. > > > > > > > > Please find more details in the FLIP wiki [1]. Feedbacks and > > suggestions > > > > are appreciated. > > > > > > > > [1] > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-123%3A+DDL+and+DML+compatibility+for+Hive+connector > > > > > > > > -- > > > > Cheers, > > > > Rui Li > > > > > > > > > > > > > -- > > Best regards! > > Rui Li > > > > > -- > Best, Jingsong Lee > -- Best regards! Rui Li
