Hi, I didn't mean to unify parser for Flink SQL and Hive SQL. I mean we should not put hive things to planner. Because planner have set conformance. So the parser already know the dialect things.
A simple way is implement a Flink SqlParserImplFactory with conformance. We can limit dialect things to parser module. Best, Jingsong Lee On Fri, Apr 10, 2020 at 4:16 PM Rui Li <lirui.fu...@gmail.com> wrote: > 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 > -- Best, Jingsong Lee
