Changing my +1 to +0. We have to make reasonable accommodations for our users. Glad we had this discussion.
> On Apr 24, 2020, at 11:10 AM, Rui Wang <amaliu...@apache.org> wrote: > > Hi Timo, > > My intention is to fully drop concepts such as SqlGroupedWindowFunction and > auxiliary group functions, which include relevant code in parser/syntax, > operator, planner, etc. > > Since you mentioned the need for more time to migrate. How many Calcite > releases that you think can probably leave enough buffer time? (Calcite > schedules 4 releases a year. So say 2 releases will give 6 months) > > > -Rui > > On Fri, Apr 24, 2020 at 1:50 AM Timo Walther <twal...@apache.org> wrote: > >> Hi everyone, >> >> so far Apache Flink depends on this feature. We are fine with improving >> the SQL compliance and eventually dropping GROUP BY TUMBLE/HOP/SESSION >> in the future. However, we would like to give our users some time to >> migrate their existing pipelines. >> >> What does dropping mean for Calcite? Will users of Calcite be able to >> still support this syntax? In particular, are you intending to also drop >> concepts such as SqlGroupedWindowFunction and auxiliary group functions? >> Or are you intending to just remove entries from Calcite's default >> operator table? >> >> Regards, >> Timo >> >> >> On 24.04.20 10:30, Julian Hyde wrote: >>> +1 >>> >>> Let’s remove TUMBLE etc from the GROUP BY clause. Since this is a SQL >> change, not an API change, I don’t we need to give notice. Let’s just do it. >>> >>> Julian >>> >>>> On Apr 22, 2020, at 4:05 PM, Rui Wang <amaliu...@apache.org> wrote: >>>> >>>> Made a mistake on the example above, and update it as follows: >>>> >>>> // Table function windowing syntax. >>>> SELECT >>>> product_id, count(*), window_start >>>> FROM TABLE(TUMBLE(order, DESCRIPTOR(rowtime), INTERVAL '1' hour)) >>>> GROUP BY product_id, window_start >>>> >>>>> On Wed, Apr 22, 2020 at 2:31 PM Rui Wang <amaliu...@apache.org> wrote: >>>>> >>>>> Hi community, >>>>> >>>>> I want to kick off a discussion about deprecating grouped window >> functions >>>>> (GROUP BY TUMBLE/HOP/SESSION) as the table function windowing support >>>>> becomes a thing [1] (FROM TABLE(TUMBLE/HOP/SESSION)). The current >> stage of >>>>> table function windowing is TUMBLE support is checked in. HOP and >> SESSION >>>>> support is likely to be merged in 1.23.0. >>>>> >>>>> A briefly example of two different windowing syntax: >>>>> >>>>> // Grouped window functions. >>>>> SELECT >>>>> product_id, count(*), TUMBLE_START() as window_start >>>>> FROM order >>>>> GROUP BY product_id, TUMBLE(rowtime, INTERVAL '1' hour); // an hour >> long >>>>> fixed window size. >>>>> >>>>> // Table function windowing syntax. >>>>> SELECT >>>>> product_id, count(*), window_start >>>>> FROM TABLE(TUMBLE(order, DESCRIPTOR(.rowtime), INTERVAL '1' hour) >>>>> GROUP BY product_id >>>>> >>>>> I am giving a short, selective comparison as the following: >>>>> >>>>> The places that table function windowing behaves better >>>>> 1) no GROUPING/GROUP BY enforced. It becomes a problem in streaming >> JOIN. >>>>> For example, one use case is for each hour, apply a JOIN on two >> streams. In >>>>> this case, no GROUP BY is needed. >>>>> 2) grouped window functions allow multiple calls in GROUP BY. For >> example, >>>>> from SQL syntax perspective, GROUP BY TUMBLE(...), HOP(...), >> SESSION(...) >>>>> is not wrong, but it is an illegal query. >>>>> 3) Calcite includes an Enumerable implementation of table function >>>>> windowing, while grouped window functions do not have that. >>>>> >>>>> >>>>> The places that table function windowing behaves worse >>>>> 1) table function windowing adds "window_start", "window_end" into >> table >>>>> directly, which increases the volume of data (number of rows * >>>>> sizeof(timestamp) * 2). >>>>> >>>>> >>>>> I want to focus on discussing two questions in this thread: >>>>> 1) Do people support deprecating grouped window functions? >>>>> 2) By which version people prefer to make grouped window functions >>>>> completely removed?(if 1) is yes). >>>>> >>>>> >>>>> >>>>> [1]: https://jira.apache.org/jira/browse/CALCITE-3271 >>>>> >>>>> >>>>> -Rui >>>>> >> >>
