Thanks Jingsong for starting the discussion. The general design of the FLIP looks good to me. +1 for the FLIP. It's time to get rid of the old Expression!
Regarding to the function behavior, shall we also include new functions from blink planner (e.g. LISTAGG, REGEXP, TO_DATE, etc..) ? Best, Jark On Wed, 14 Aug 2019 at 23:34, Timo Walther <twal...@apache.org> wrote: > Hi Jingsong, > > thanks for writing down this FLIP. Big +1 from my side to finally get > rid of PlannerExpressions and have consistent and well-defined behavior > for Table API and SQL updated to FLIP-37. > > We might need to discuss some of the behavior of particular functions > but this should not affect the actual FLIP-51. > > Regards, > Timo > > > Am 13.08.19 um 12:55 schrieb JingsongLee: > > Hi everyone, > > > > We would like to start a discussion thread on "FLIP-51: Rework of the > > Expression Design"(Design doc: [1], FLIP: [2]), where we describe how > > to improve the new java Expressions to work with type inference and > > convert expression to the calcite RexNode. This is a follow-up plan > > for FLIP-32[3] and FLIP-37[4]. This FLIP is mostly based on FLIP-37. > > > > This FLIP addresses several shortcomings of current: > > - New Expressions still use PlannerExpressions to type inference and > > to RexNode. Flnk-planner and blink-planner have a lot of repetitive > code > > and logic. > > - Let TableApi and Cacite definitions consistent. > > - Reduce the complexity of Function development. > > - Powerful Function for user. > > > > Key changes can be summarized as follows: > > - Improve the interface of FunctionDefinition. > > - Introduce type inference for built-in functions. > > - Introduce ExpressionConverter to convert Expression to calcite > > RexNode. > > - Remove repetitive code and logic in planners. > > > > I also listed type inference and behavior of all built-in functions [5], > to > > verify that the interface is satisfied. After introduce type inference to > > table-common module, planners should have a unified function behavior. > > And this gives the community also the chance to quickly discuss types > > and behavior of functions a last time before they are declared stable. > > > > Looking forward to your feedbacks. Thank you. > > > > [1] > https://docs.google.com/document/d/1yFDyquMo_-VZ59vyhaMshpPtg7p87b9IYdAtMXv5XmM/edit?usp=sharing > > [2] > https://cwiki.apache.org/confluence/display/FLINK/FLIP-51%3A+Rework+of+the+Expression+Design > > [3] > https://cwiki.apache.org/confluence/display/FLINK/FLIP-32%3A+Restructure+flink-table+for+future+contributions > > [4] > https://cwiki.apache.org/confluence/display/FLINK/FLIP-37%3A+Rework+of+the+Table+API+Type+System > > [5] > https://docs.google.com/document/d/1fyVmdGgbO1XmIyQ1BaoG_h5BcNcF3q9UJ1Bj1euO240/edit?usp=sharing > > > > Best, > > Jingsong Lee > > >
