"SYSTEM" sounds good to me. FYI, this FLIP only impacts low level of the SQL function stack and won't actually involve any DDL, thus I will just document the decision and we should keep it in mind when it's time to implement the DDLs.
I'm in the process of updating the FLIP to reflect changes required for option #2, will send a new version for review soon. On Fri, Sep 20, 2019 at 4:02 PM Dawid Wysakowicz <dwysakow...@apache.org> wrote: > I also like the 'System' keyword. I think we can assume we reached > consensus on this topic. > > On Sat, 21 Sep 2019, 06:37 Xuefu Z, <usxu...@gmail.com> wrote: > > > +1 for using the keyword "SYSTEM". Thanks to Timo for chiming in! > > > > --Xuefu > > > > On Fri, Sep 20, 2019 at 3:28 PM Timo Walther <twal...@apache.org> wrote: > > > > > Hi everyone, > > > > > > sorry, for the late replay. I give also +1 for option #2. Thus, I guess > > > we have a clear winner. > > > > > > I would also like to find a better keyword/syntax for this statement. > > > Esp. the BUILTIN keyword can confuse people, because it could be > written > > > as BUILTIN, BUILDIN, BUILT_IN, or BUILD_IN. And we would need to > > > introduce a new reserved keyword in the parser which affects also > > > non-DDL queries. How about: > > > > > > CREATE TEMPORARY SYSTEM FUNCTION xxx > > > > > > The SYSTEM keyword is already a reserved keyword and in FLIP-66 we are > > > discussing to prefix some of the function with a SYSTEM_ prefix like > > > SYSTEM_WATERMARK. Also SQL defines syntax like "FOR SYSTEM_TIME AS OF". > > > > > > What do you think? > > > > > > Thanks, > > > Timo > > > > > > > > > On 20.09.19 05:45, Bowen Li wrote: > > > > Another reason I prefer "CREATE TEMPORARY BUILTIN FUNCTION" over > "ALTER > > > > BUILTIN FUNCTION xxx TEMPORARILY" is - what if users want to drop the > > > > temporary built-in function in the same session? With the former one, > > > they > > > > can run something like "DROP TEMPORARY BUILTIN FUNCTION"; With the > > latter > > > > one, I'm not sure how users can "restore" the original builtin > function > > > > easily from an "altered" function without introducing further > > nonstandard > > > > SQL syntax. > > > > > > > > Also please pardon me as I realized using net may not be a good > idea... > > > I'm > > > > trying to fit this vote into cases listed in Flink Bylaw [1]. > > > > > > > > >From the following result, the majority seems to be #2 too as it has > > the > > > > most approval so far and doesn't have strong "-1". > > > > > > > > #1：3 (+1), 1 (0), 4(-1) > > > > #2：4(0), 3 (+1), 1(+0.5) > > > > * Dawid -1/0 depending on keyword > > > > #3：2(+1), 3(-1), 3(0) > > > > > > > > [1] > > > > > > > > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=120731026 > > > > > > > > On Thu, Sep 19, 2019 at 10:30 AM Bowen Li <bowenl...@gmail.com> > wrote: > > > > > > > >> Hi, > > > >> > > > >> Thanks everyone for your votes. I summarized the result as > following: > > > >> > > > >> #1：3 (+1), 1 (0), 4(-1) - net: -1 > > > >> #2：4(0), 2 (+1), 1(+0.5) - net: +2.5 > > > >> Dawid -1/0 depending on keyword > > > >> #3：2(+1), 3(-1), 3(0) - net: -1 > > > >> > > > >> Given the result, I'd like to change my vote for #2 from 0 to +1, to > > > make > > > >> it a stronger case with net +3.5. So the votes so far are: > > > >> > > > >> #1：3 (+1), 1 (0), 4(-1) - net: -1 > > > >> #2：4(0), 3 (+1), 1(+0.5) - net: +3.5 > > > >> Dawid -1/0 depending on keyword > > > >> #3：2(+1), 3(-1), 3(0) - net: -1 > > > >> > > > >> What do you think? Do you think we can conclude with this result? Or > > > would > > > >> you like to take it as a formal FLIP vote with 3 days voting period? > > > >> > > > >> BTW, I'd prefer "CREATE TEMPORARY BUILTIN FUNCTION" over "ALTER > > BUILTIN > > > >> FUNCTION xxx TEMPORARILY" because > > > >> 1. the syntax is more consistent with "CREATE FUNCTION" and "CREATE > > > >> TEMPORARY FUNCTION" > > > >> 2. "ALTER BUILTIN FUNCTION xxx TEMPORARILY" implies it alters a > > built-in > > > >> function but it actually doesn't, the logic only creates a temp > > function > > > >> with higher priority than that built-in function in ambiguous > > resolution > > > >> order; and it would behave inconsistently with "ALTER FUNCTION". > > > >> > > > >> > > > >> > > > >> On Thu, Sep 19, 2019 at 2:58 AM Fabian Hueske <fhue...@gmail.com> > > > wrote: > > > >> > > > >>> I agree, it's very similar from the implementation point of view > and > > > the > > > >>> implications. > > > >>> > > > >>> IMO, the difference is mostly on the mental model for the user. > > > >>> Instead of having a special class of temporary functions that have > > > >>> precedence over builtin functions it suggests to temporarily change > > > >>> built-in functions. > > > >>> > > > >>> Fabian > > > >>> > > > >>> Am Do., 19. Sept. 2019 um 11:52 Uhr schrieb Kurt Young < > > > ykt...@gmail.com > > > >>>> : > > > >>>> Hi Fabian, > > > >>>> > > > >>>> I think it's almost the same with #2 with different keyword: > > > >>>> > > > >>>> CREATE TEMPORARY BUILTIN FUNCTION xxx > > > >>>> > > > >>>> Best, > > > >>>> Kurt > > > >>>> > > > >>>> > > > >>>> On Thu, Sep 19, 2019 at 5:50 PM Fabian Hueske <fhue...@gmail.com> > > > >>> wrote: > > > >>>>> Hi, > > > >>>>> > > > >>>>> I thought about it a bit more and think that there is some good > > value > > > >>> in > > > >>>> my > > > >>>>> last proposal. > > > >>>>> > > > >>>>> A lot of complexity comes from the fact that we want to allow > > > >>> overriding > > > >>>>> built-in functions which are differently addressed as other > > functions > > > >>>> (and > > > >>>>> db objects). > > > >>>>> We could just have "CREATE TEMPORARY FUNCTION" do exactly the > same > > > >>> thing > > > >>>> as > > > >>>>> "CREATE FUNCTION" and treat both functions exactly the same > except > > > >>> that: > > > >>>>> 1) temp functions disappear at the end of the session > > > >>>>> 2) temp function are resolved before other functions > > > >>>>> > > > >>>>> This would be Dawid's proposal from the beginning of this thread > > (in > > > >>> case > > > >>>>> you still remember... ;-) ) > > > >>>>> > > > >>>>> Temporarily overriding built-in functions would be supported with > > an > > > >>>>> explicit command like > > > >>>>> > > > >>>>> ALTER BUILTIN FUNCTION xxx TEMPORARILY AS ... > > > >>>>> > > > >>>>> This would also address the concerns about accidentally changing > > the > > > >>>>> semantics of built-in functions. > > > >>>>> IMO, it can't get much more explicit than the above command. > > > >>>>> > > > >>>>> Sorry for bringing up a new option in the middle of the > discussion, > > > >>> but > > > >>>> as > > > >>>>> I said, I think it has a bunch of benefits and I don't see major > > > >>>> drawbacks > > > >>>>> (maybe you do?). > > > >>>>> > > > >>>>> What do you think? > > > >>>>> > > > >>>>> Fabian > > > >>>>> > > > >>>>> Am Do., 19. Sept. 2019 um 11:24 Uhr schrieb Fabian Hueske < > > > >>>>> fhue...@gmail.com > > > >>>>>> : > > > >>>>>> Hi everyone, > > > >>>>>> > > > >>>>>> I thought again about option #1 and something that I don't like > is > > > >>> that > > > >>>>>> the resolved address of xyz is different in "CREATE FUNCTION > xyz" > > > >>> and > > > >>>>>> "CREATE TEMPORARY FUNCTION xyz". > > > >>>>>> IMO, adding the keyword "TEMPORARY" should only change the > > > >>> lifecycle of > > > >>>>>> the function, but not where it is located. This implicitly > changed > > > >>>>> location > > > >>>>>> might be confusing for users. > > > >>>>>> After all, a temp function should behave pretty much like any > > other > > > >>>>>> function, except for the fact that it disappears when the > session > > is > > > >>>>> closed. > > > >>>>>> Approach #2 with the additional keyword would make that pretty > > > >>> clear, > > > >>>>> IMO. > > > >>>>>> However, I neither like GLOBAL (for reasons mentioned by Dawid) > or > > > >>>>> BUILDIN > > > >>>>>> (we are not adding a built-in function). > > > >>>>>> So I'd be OK with #2 if we find a good keyword. In fact, > approach > > #2 > > > >>>>> could > > > >>>>>> also be an alias for approach #3 to avoid explicit specification > > of > > > >>> the > > > >>>>>> system catalog/db. > > > >>>>>> > > > >>>>>> Approach #3 would be consistent with other db objects and the > > > >>> "CREATE > > > >>>>>> FUNCTION" statement. > > > >>>>>> Adding system catalog/db seems rather complex, but then again > how > > > >>> often > > > >>>>> do > > > >>>>>> we expect users to override built-in functions? If this becomes > a > > > >>> major > > > >>>>>> issue, we can still add option #2 as an alias. > > > >>>>>> > > > >>>>>> Not sure what's the best approach from an internal point of > view, > > > >>> but I > > > >>>>>> certainly think that consistent behavior is important. > > > >>>>>> Hence my votes are: > > > >>>>>> > > > >>>>>> -1 for #1 > > > >>>>>> 0 for #2 > > > >>>>>> 0 for #3 > > > >>>>>> > > > >>>>>> Btw. Did we consider a completely separate command for > overriding > > > >>>>> built-in > > > >>>>>> functions like "ALTER BUILTIN FUNCTION xxx TEMPORARILY AS ..."? > > > >>>>>> > > > >>>>>> Cheers, Fabian > > > >>>>>> > > > >>>>>> > > > >>>>>> Am Do., 19. Sept. 2019 um 11:03 Uhr schrieb JingsongLee > > > >>>>>> <lzljs3620...@aliyun.com.invalid>: > > > >>>>>> > > > >>>>>>> I know Hive and Spark can shadow built-in functions by > temporary > > > >>>>> function. > > > >>>>>>> Mysql, Oracle, Sql server can not shadow. > > > >>>>>>> User can use full names to access functions instead of > shadowing. > > > >>>>>>> > > > >>>>>>> So I think it is a completely new thing, and the direct way to > > deal > > > >>>> with > > > >>>>>>> new things is to add new grammar. So, > > > >>>>>>> +1 for #2, +0 for #3, -1 for #1 > > > >>>>>>> > > > >>>>>>> Best, > > > >>>>>>> Jingsong Lee > > > >>>>>>> > > > >>>>>>> > > > >>>>>>> > > ------------------------------------------------------------------ > > > >>>>>>> From:Kurt Young <ykt...@gmail.com> > > > >>>>>>> Send Time:2019年9月19日(星期四) 16:43 > > > >>>>>>> To:dev <dev@flink.apache.org> > > > >>>>>>> Subject:Re: [DISCUSS] FLIP-57 - Rework FunctionCatalog > > > >>>>>>> > > > >>>>>>> And let me make my vote complete: > > > >>>>>>> > > > >>>>>>> -1 for #1 > > > >>>>>>> +1 for #2 with different keyword > > > >>>>>>> -0 for #3 > > > >>>>>>> > > > >>>>>>> Best, > > > >>>>>>> Kurt > > > >>>>>>> > > > >>>>>>> > > > >>>>>>> On Thu, Sep 19, 2019 at 4:40 PM Kurt Young <ykt...@gmail.com> > > > >>> wrote: > > > >>>>>>>> Looks like I'm the only person who is willing to +1 to #2 for > > now > > > >>>> :-) > > > >>>>>>>> But I would suggest to change the keyword from GLOBAL to > > > >>>>>>>> something like BUILTIN. > > > >>>>>>>> > > > >>>>>>>> I think #2 and #3 are almost the same proposal, just with > > > >>> different > > > >>>>>>>> format to indicate whether it want to override built-in > > > >>> functions. > > > >>>>>>>> My biggest reason to choose it is I want this behavior be > > > >>> consistent > > > >>>>>>>> with temporal tables. I will give some examples to show the > > > >>> behavior > > > >>>>>>>> and also make sure I'm not misunderstanding anything here. > > > >>>>>>>> > > > >>>>>>>> For most DBs, when user create a temporary table with: > > > >>>>>>>> > > > >>>>>>>> CREATE TEMPORARY TABLE t1 > > > >>>>>>>> > > > >>>>>>>> It's actually equivalent with: > > > >>>>>>>> > > > >>>>>>>> CREATE TEMPORARY TABLE `curent_db`.t1 > > > >>>>>>>> > > > >>>>>>>> If user change current database, they will not be able to > access > > > >>> t1 > > > >>>>>>> without > > > >>>>>>>> fully qualified name, .i.e db1.t1 (assuming db1 is current > > > >>> database > > > >>>>> when > > > >>>>>>>> this temporary table is created). > > > >>>>>>>> > > > >>>>>>>> Only #2 and #3 followed this behavior and I would vote for > this > > > >>>> since > > > >>>>>>> this > > > >>>>>>>> makes such behavior consistent through temporal tables and > > > >>>> functions. > > > >>>>>>>> Why I'm not voting for #3 is a special catalog and database > just > > > >>>> looks > > > >>>>>>> very > > > >>>>>>>> hacky to me. It gave a imply that our built-in functions saved > > > >>> at a > > > >>>>>>>> special > > > >>>>>>>> catalog and database, which is actually not. Introducing a > > > >>> dedicated > > > >>>>>>>> keyword > > > >>>>>>>> like CREATE TEMPORARY BUILTIN FUNCTION looks more clear and > > > >>>>>>>> straightforward. One can argue that we should avoid > introducing > > > >>> new > > > >>>>>>>> keyword, > > > >>>>>>>> but it's also very rare that a system can overwrite built-in > > > >>>>> functions. > > > >>>>>>>> Since we > > > >>>>>>>> decided to support this, introduce a new keyword is not a big > > > >>> deal > > > >>>>> IMO. > > > >>>>>>>> Best, > > > >>>>>>>> Kurt > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>>> On Thu, Sep 19, 2019 at 3:07 PM Piotr Nowojski < > > > >>> pi...@ververica.com > > > >>>>>>>> wrote: > > > >>>>>>>> > > > >>>>>>>>> Hi, > > > >>>>>>>>> > > > >>>>>>>>> It is a quite long discussion to follow and I hope I didn’t > > > >>>>>>> misunderstand > > > >>>>>>>>> anything. From the proposals presented by Xuefu I would vote: > > > >>>>>>>>> > > > >>>>>>>>> -1 for #1 and #2 > > > >>>>>>>>> +1 for #3 > > > >>>>>>>>> > > > >>>>>>>>> Besides #3 being IMO more general and more consistent, having > > > >>>>> qualified > > > >>>>>>>>> names (#3) would help/make easier for someone to use cross > > > >>>>>>>>> databases/catalogs queries (joining multiple data > > sets/streams). > > > >>>> For > > > >>>>>>>>> example with some functions to manipulate/clean up/convert > the > > > >>>> stored > > > >>>>>>> data > > > >>>>>>>>> in different catalogs registered in the respective catalogs. > > > >>>>>>>>> > > > >>>>>>>>> Piotrek > > > >>>>>>>>> > > > >>>>>>>>>> On 19 Sep 2019, at 06:35, Jark Wu <imj...@gmail.com> wrote: > > > >>>>>>>>>> > > > >>>>>>>>>> I agree with Xuefu that inconsistent handling with all the > > > >>> other > > > >>>>>>>>> objects is > > > >>>>>>>>>> not a big problem. > > > >>>>>>>>>> > > > >>>>>>>>>> Regarding to option#3, the special "system.system" namespace > > > >>> may > > > >>>>>>> confuse > > > >>>>>>>>>> users. > > > >>>>>>>>>> Users need to know the set of built-in function names to > know > > > >>>> when > > > >>>>> to > > > >>>>>>>>> use > > > >>>>>>>>>> "system.system" namespace. > > > >>>>>>>>>> What will happen if user registers a non-builtin function > name > > > >>>>> under > > > >>>>>>> the > > > >>>>>>>>>> "system.system" namespace? > > > >>>>>>>>>> Besides, I think it doesn't solve the "explode" problem I > > > >>>> mentioned > > > >>>>>>> at > > > >>>>>>>>> the > > > >>>>>>>>>> beginning of this thread. > > > >>>>>>>>>> > > > >>>>>>>>>> So here is my vote: > > > >>>>>>>>>> > > > >>>>>>>>>> +1 for #1 > > > >>>>>>>>>> 0 for #2 > > > >>>>>>>>>> -1 for #3 > > > >>>>>>>>>> > > > >>>>>>>>>> Best, > > > >>>>>>>>>> Jark > > > >>>>>>>>>> > > > >>>>>>>>>> > > > >>>>>>>>>> On Thu, 19 Sep 2019 at 08:38, Xuefu Z <usxu...@gmail.com> > > > >>> wrote: > > > >>>>>>>>>>> @Dawid, Re: we also don't need additional referencing the > > > >>>>>>>>> specialcatalog > > > >>>>>>>>>>> anywhere. > > > >>>>>>>>>>> > > > >>>>>>>>>>> True. But once we allow such reference, then user can do so > > > >>> in > > > >>>> any > > > >>>>>>>>> possible > > > >>>>>>>>>>> place where a function name is expected, for which we have > to > > > >>>>>>> handle. > > > >>>>>>>>>>> That's a big difference, I think. > > > >>>>>>>>>>> > > > >>>>>>>>>>> Thanks, > > > >>>>>>>>>>> Xuefu > > > >>>>>>>>>>> > > > >>>>>>>>>>> On Wed, Sep 18, 2019 at 5:25 PM Dawid Wysakowicz < > > > >>>>>>>>>>> wysakowicz.da...@gmail.com> > > > >>>>>>>>>>> wrote: > > > >>>>>>>>>>> > > > >>>>>>>>>>>> @Bowen I am not suggesting introducing additional > catalog. I > > > >>>>> think > > > >>>>>>> we > > > >>>>>>>>>>> need > > > >>>>>>>>>>>> to get rid of the current built-in catalog. > > > >>>>>>>>>>>> > > > >>>>>>>>>>>> @Xuefu in option #3 we also don't need additional > > > >>> referencing > > > >>>> the > > > >>>>>>>>> special > > > >>>>>>>>>>>> catalog anywhere else besides in the CREATE statement. The > > > >>>>>>> resolution > > > >>>>>>>>>>>> behaviour is exactly the same in both options. > > > >>>>>>>>>>>> > > > >>>>>>>>>>>> On Thu, 19 Sep 2019, 08:17 Xuefu Z, <usxu...@gmail.com> > > > >>> wrote: > > > >>>>>>>>>>>>> Hi Dawid, > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> "GLOBAL" is a temporary keyword that was given to the > > > >>>> approach. > > > >>>>> It > > > >>>>>>>>> can > > > >>>>>>>>>>> be > > > >>>>>>>>>>>>> changed to something else for better. > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> The difference between this and the #3 approach is that > we > > > >>>> only > > > >>>>>>> need > > > >>>>>>>>>>> the > > > >>>>>>>>>>>>> keyword for this create DDL. For other places (such as > > > >>>> function > > > >>>>>>>>>>>>> referencing), no keyword or special namespace is needed. > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> Thanks, > > > >>>>>>>>>>>>> Xuefu > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> On Wed, Sep 18, 2019 at 4:32 PM Dawid Wysakowicz < > > > >>>>>>>>>>>>> wysakowicz.da...@gmail.com> > > > >>>>>>>>>>>>> wrote: > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Hi, > > > >>>>>>>>>>>>>> I think it makes sense to start voting at this point. > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Option 1: Only 1-part identifiers > > > >>>>>>>>>>>>>> PROS: > > > >>>>>>>>>>>>>> - allows shadowing built-in functions > > > >>>>>>>>>>>>>> CONS: > > > >>>>>>>>>>>>>> - incosistent with all the other objects, both > permanent & > > > >>>>>>> temporary > > > >>>>>>>>>>>>>> - does not allow shadowing catalog functions > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Option 2: Special keyword for built-in function > > > >>>>>>>>>>>>>> I think this is quite similar to the special catalog/db. > > > >>> The > > > >>>>>>> thing I > > > >>>>>>>>>>> am > > > >>>>>>>>>>>>>> strongly against in this proposal is the GLOBAL keyword. > > > >>> This > > > >>>>>>>>> keyword > > > >>>>>>>>>>>>> has a > > > >>>>>>>>>>>>>> meaning in rdbms systems and means a function that is > > > >>> present > > > >>>>>>> for a > > > >>>>>>>>>>>>>> lifetime of a session in which it was created, but > > > >>> available > > > >>>> in > > > >>>>>>> all > > > >>>>>>>>>>>> other > > > >>>>>>>>>>>>>> sessions. Therefore I really don't want to use this > > > >>> keyword > > > >>>> in > > > >>>>> a > > > >>>>>>>>>>>>> different > > > >>>>>>>>>>>>>> context. > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Option 3: Special catalog/db > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> PROS: > > > >>>>>>>>>>>>>> - allows shadowing built-in functions > > > >>>>>>>>>>>>>> - allows shadowing catalog functions > > > >>>>>>>>>>>>>> - consistent with other objects > > > >>>>>>>>>>>>>> CONS: > > > >>>>>>>>>>>>>> - we introduce a special namespace for built-in > functions > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> I don't see a problem with introducing the special > > > >>> namespace. > > > >>>>> In > > > >>>>>>> the > > > >>>>>>>>>>>> end > > > >>>>>>>>>>>>> it > > > >>>>>>>>>>>>>> is very similar to the keyword approach. In this case > the > > > >>>>>>> catalog/db > > > >>>>>>>>>>>>>> combination would be the "keyword" > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Therefore my votes: > > > >>>>>>>>>>>>>> Option 1: -0 > > > >>>>>>>>>>>>>> Option 2: -1 (I might change to +0 if we can come up > with > > > >>> a > > > >>>>>>> better > > > >>>>>>>>>>>>> keyword) > > > >>>>>>>>>>>>>> Option 3: +1 > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>>> Dawid > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> On Thu, 19 Sep 2019, 05:12 Xuefu Z, <usxu...@gmail.com> > > > >>>> wrote: > > > >>>>>>>>>>>>>>> Hi Aljoscha, > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Thanks for the summary and these are great questions to > > > >>> be > > > >>>>>>>>>>> answered. > > > >>>>>>>>>>>>> The > > > >>>>>>>>>>>>>>> answer to your first question is clear: there is a > > > >>> general > > > >>>>>>>>>>> agreement > > > >>>>>>>>>>>> to > > > >>>>>>>>>>>>>>> override built-in functions with temp functions. > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> However, your second and third questions are sort of > > > >>>> related, > > > >>>>>>> as a > > > >>>>>>>>>>>>>> function > > > >>>>>>>>>>>>>>> reference can be either just function name (like > "func") > > > >>> or > > > >>>> in > > > >>>>>>> the > > > >>>>>>>>>>>> form > > > >>>>>>>>>>>>>> or > > > >>>>>>>>>>>>>>> "cat.db.func". When a reference is just function name, > it > > > >>>> can > > > >>>>>>> mean > > > >>>>>>>>>>>>>> either a > > > >>>>>>>>>>>>>>> built-in function or a function defined in the current > > > >>>> cat/db. > > > >>>>>>> If > > > >>>>>>>>>>> we > > > >>>>>>>>>>>>>>> support overriding a built-in function with a temp > > > >>> function, > > > >>>>>>> such > > > >>>>>>>>>>>>>>> overriding can also cover a function in the current > > > >>> cat/db. > > > >>>>>>>>>>>>>>> I think what Timo referred as "overriding a catalog > > > >>>> function" > > > >>>>>>>>>>> means a > > > >>>>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>> function defined as "cat.db.func" overrides a catalog > > > >>>> function > > > >>>>>>>>>>> "func" > > > >>>>>>>>>>>>> in > > > >>>>>>>>>>>>>>> cat/db even if cat/db is not current. To support this, > > > >>> temp > > > >>>>>>>>>>> function > > > >>>>>>>>>>>>> has > > > >>>>>>>>>>>>>> to > > > >>>>>>>>>>>>>>> be tied to a cat/db. What's why I said above that the > 2nd > > > >>>> and > > > >>>>>>> 3rd > > > >>>>>>>>>>>>>> questions > > > >>>>>>>>>>>>>>> are related. The problem with such support is the > > > >>> ambiguity > > > >>>>> when > > > >>>>>>>>>>> user > > > >>>>>>>>>>>>>>> defines a function w/o namespace, "CREATE TEMPORARY > > > >>> FUNCTION > > > >>>>>>> func > > > >>>>>>>>>>>> ...". > > > >>>>>>>>>>>>>>> Here "func" can means a global temp function, or a temp > > > >>>>>>> function in > > > >>>>>>>>>>>>>> current > > > >>>>>>>>>>>>>>> cat/db. If we can assume the former, this creates an > > > >>>>>>> inconsistency > > > >>>>>>>>>>>>>> because > > > >>>>>>>>>>>>>>> "CREATE FUNCTION func" actually means a function in > > > >>> current > > > >>>>>>> cat/db. > > > >>>>>>>>>>>> If > > > >>>>>>>>>>>>> we > > > >>>>>>>>>>>>>>> assume the latter, then there is no way for user to > > > >>> create a > > > >>>>>>> global > > > >>>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>> function. > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Giving a special namespace for built-in functions may > > > >>> solve > > > >>>>> the > > > >>>>>>>>>>>>> ambiguity > > > >>>>>>>>>>>>>>> problem above, but it also introduces artificial > > > >>>>>>> catalog/database > > > >>>>>>>>>>>> that > > > >>>>>>>>>>>>>>> needs special treatment and pollutes the cleanness of > > > >>> the > > > >>>>>>> code. I > > > >>>>>>>>>>>>> would > > > >>>>>>>>>>>>>>> rather introduce a syntax in DDL to solve the problem, > > > >>> like > > > >>>>>>> "CREATE > > > >>>>>>>>>>>>>>> [GLOBAL] TEMPORARY FUNCTION func". > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Thus, I'd like to summarize a few candidate proposals > for > > > >>>>> voting > > > >>>>>>>>>>>>>> purposes: > > > >>>>>>>>>>>>>>> 1. Support only global, temporary functions without > > > >>>> namespace. > > > >>>>>>> Such > > > >>>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>> functions overrides built-in functions and catalog > > > >>> functions > > > >>>>> in > > > >>>>>>>>>>>> current > > > >>>>>>>>>>>>>>> cat/db. The resolution order is: temp functions -> > > > >>> built-in > > > >>>>>>>>>>> functions > > > >>>>>>>>>>>>> -> > > > >>>>>>>>>>>>>>> catalog functions. (Partially or fully qualified > > > >>> functions > > > >>>> has > > > >>>>>>> no > > > >>>>>>>>>>>>>>> ambiguity!) > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> 2. In addition to #1, support creating and referencing > > > >>>>> temporary > > > >>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>> associated with a cat/db with "GLOBAL" qualifier in DDL > > > >>> for > > > >>>>>>> global > > > >>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>> functions. The resolution order is: global temp > > > >>> functions -> > > > >>>>>>>>>>> built-in > > > >>>>>>>>>>>>>>> functions -> temp functions in current cat/db -> > catalog > > > >>>>>>> function. > > > >>>>>>>>>>>>>>> (Resolution for partially or fully qualified function > > > >>>>> reference > > > >>>>>>> is: > > > >>>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>> functions -> persistent functions.) > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> 3. In addition to #1, support creating and referencing > > > >>>>> temporary > > > >>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>> associated with a cat/db with a special namespace for > > > >>>> built-in > > > >>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>> and global temp functions. The resolution is the same > as > > > >>> #2, > > > >>>>>>> except > > > >>>>>>>>>>>>> that > > > >>>>>>>>>>>>>>> the special namespace might be prefixed to a reference > > > >>> to a > > > >>>>>>>>>>> built-in > > > >>>>>>>>>>>>>>> function or global temp function. (In absence of the > > > >>> special > > > >>>>>>>>>>>> namespace, > > > >>>>>>>>>>>>>> the > > > >>>>>>>>>>>>>>> resolution order is the same as in #2.) > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> My personal preference is #1, given the unknown use > case > > > >>> and > > > >>>>>>>>>>>> introduced > > > >>>>>>>>>>>>>>> complexity for #2 and #3. However, #2 is an acceptable > > > >>>>>>> alternative. > > > >>>>>>>>>>>>> Thus, > > > >>>>>>>>>>>>>>> my votes are: > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> +1 for #1 > > > >>>>>>>>>>>>>>> +0 for #2 > > > >>>>>>>>>>>>>>> -1 for #3 > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Everyone, please cast your vote (in above format > > > >>> please!), > > > >>>> or > > > >>>>>>> let > > > >>>>>>>>>>> me > > > >>>>>>>>>>>>> know > > > >>>>>>>>>>>>>>> if you have more questions or other candidates. > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Thanks, > > > >>>>>>>>>>>>>>> Xuefu > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> On Wed, Sep 18, 2019 at 6:42 AM Aljoscha Krettek < > > > >>>>>>>>>>>> aljos...@apache.org> > > > >>>>>>>>>>>>>>> wrote: > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> Hi, > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> I think this discussion and the one for FLIP-64 are > very > > > >>>>>>>>>>> connected. > > > >>>>>>>>>>>>> To > > > >>>>>>>>>>>>>>>> resolve the differences, think we have to think about > > > >>> the > > > >>>>> basic > > > >>>>>>>>>>>>>>> principles > > > >>>>>>>>>>>>>>>> and find consensus there. The basic questions I see > are: > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> - Do we want to support overriding builtin functions? > > > >>>>>>>>>>>>>>>> - Do we want to support overriding catalog functions? > > > >>>>>>>>>>>>>>>> - And then later: should temporary functions be tied > to > > > >>> a > > > >>>>>>>>>>>>>>>> catalog/database? > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> I don’t have much to say about these, except that we > > > >>> should > > > >>>>>>>>>>>> somewhat > > > >>>>>>>>>>>>>>> stick > > > >>>>>>>>>>>>>>>> to what the industry does. But I also understand that > > > >>> the > > > >>>>>>>>>>> industry > > > >>>>>>>>>>>> is > > > >>>>>>>>>>>>>>>> already very divided on this. > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>>>>> Aljoscha > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> On 18. Sep 2019, at 11:41, Jark Wu <imj...@gmail.com > > > > > >>>>> wrote: > > > >>>>>>>>>>>>>>>>> Hi, > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> +1 to strive for reaching consensus on the remaining > > > >>>> topics. > > > >>>>>>> We > > > >>>>>>>>>>>> are > > > >>>>>>>>>>>>>>>> close to the truth. It will waste a lot of time if we > > > >>>> resume > > > >>>>>>> the > > > >>>>>>>>>>>>> topic > > > >>>>>>>>>>>>>>> some > > > >>>>>>>>>>>>>>>> time later. > > > >>>>>>>>>>>>>>>>> +1 to “1-part/override” and I’m also fine with Timo’s > > > >>>>>>>>>>>> “cat.db.fun” > > > >>>>>>>>>>>>>> way > > > >>>>>>>>>>>>>>>> to override a catalog function. > > > >>>>>>>>>>>>>>>>> I’m not sure about “system.system.fun”, it > introduces a > > > >>>>>>>>>>>> nonexistent > > > >>>>>>>>>>>>>> cat > > > >>>>>>>>>>>>>>>> & db? And we still need to do special treatment for > the > > > >>>>>>> dedicated > > > >>>>>>>>>>>>>>>> system.system cat & db? > > > >>>>>>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>>>>>> Jark > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>> 在 2019年9月18日，06:54，Timo Walther <twal...@apache.org > > > > > >>> 写道： > > > >>>>>>>>>>>>>>>>>> Hi everyone, > > > >>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>> @Xuefu: I would like to avoid adding too many things > > > >>>>>>>>>>>>> incrementally. > > > >>>>>>>>>>>>>>>> Users should be able to override all catalog objects > > > >>>>>>> consistently > > > >>>>>>>>>>>>>>> according > > > >>>>>>>>>>>>>>>> to FLIP-64 (Support for Temporary Objects in Table > > > >>> module). > > > >>>>> If > > > >>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>>> are treated completely different, we need more code > and > > > >>>>> special > > > >>>>>>>>>>>>> cases. > > > >>>>>>>>>>>>>>> From > > > >>>>>>>>>>>>>>>> an implementation perspective, this topic only affects > > > >>> the > > > >>>>>>> lookup > > > >>>>>>>>>>>>> logic > > > >>>>>>>>>>>>>>>> which is rather low implementation effort which is > why I > > > >>>>> would > > > >>>>>>>>>>> like > > > >>>>>>>>>>>>> to > > > >>>>>>>>>>>>>>>> clarify the remaining items. As you said, we have a > > > >>> slight > > > >>>>>>>>>>> consenus > > > >>>>>>>>>>>>> on > > > >>>>>>>>>>>>>>>> overriding built-in functions; we should also strive > for > > > >>>>>>> reaching > > > >>>>>>>>>>>>>>> consensus > > > >>>>>>>>>>>>>>>> on the remaining topics. > > > >>>>>>>>>>>>>>>>>> @Dawid: I like your idea as it ensures registering > > > >>>> catalog > > > >>>>>>>>>>>> objects > > > >>>>>>>>>>>>>>>> consistent and the overriding of built-in functions > more > > > >>>>>>>>>>> explicit. > > > >>>>>>>>>>>>>>>>>> Thanks, > > > >>>>>>>>>>>>>>>>>> Timo > > > >>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>> On 17.09.19 11:59, kai wang wrote: > > > >>>>>>>>>>>>>>>>>>> hi, everyone > > > >>>>>>>>>>>>>>>>>>> I think this flip is very meaningful. it supports > > > >>>>> functions > > > >>>>>>>>>>>> that > > > >>>>>>>>>>>>>> can > > > >>>>>>>>>>>>>>> be > > > >>>>>>>>>>>>>>>>>>> shared by different catalogs and dbs, reducing the > > > >>>>>>>>>>> duplication > > > >>>>>>>>>>>> of > > > >>>>>>>>>>>>>>>> functions. > > > >>>>>>>>>>>>>>>>>>> Our group based on flink's sql parser module > > > >>> implements > > > >>>>>>>>>>> create > > > >>>>>>>>>>>>>>> function > > > >>>>>>>>>>>>>>>>>>> feature, stores the parsed function metadata and > > > >>> schema > > > >>>>> into > > > >>>>>>>>>>>>> mysql, > > > >>>>>>>>>>>>>>> and > > > >>>>>>>>>>>>>>>>>>> also customizes the catalog, customizes sql-client > to > > > >>>>>>> support > > > >>>>>>>>>>>>>> custom > > > >>>>>>>>>>>>>>>>>>> schemas and functions. Loaded, but the function is > > > >>>>> currently > > > >>>>>>>>>>>>>> global, > > > >>>>>>>>>>>>>>>> and is > > > >>>>>>>>>>>>>>>>>>> not subdivided according to catalog and db. > > > >>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>> In addition, I very much hope to participate in the > > > >>>>>>>>>>> development > > > >>>>>>>>>>>>> of > > > >>>>>>>>>>>>>>> this > > > >>>>>>>>>>>>>>>>>>> flip, I have been paying attention to the > community, > > > >>> but > > > >>>>>>>>>>> found > > > >>>>>>>>>>>> it > > > >>>>>>>>>>>>>> is > > > >>>>>>>>>>>>>>>> more > > > >>>>>>>>>>>>>>>>>>> difficult to join. > > > >>>>>>>>>>>>>>>>>>> thank you. > > > >>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>> Xuefu Z <usxu...@gmail.com> 于2019年9月17日周二 > 上午11:19写道： > > > >>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> Thanks to Tmo and Dawid for sharing thoughts. > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> It seems to me that there is a general consensus > on > > > >>>>> having > > > >>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>>>>>>> that have no namespaces and overwrite built-in > > > >>>> functions. > > > >>>>>>>>>>> (As > > > >>>>>>>>>>>> a > > > >>>>>>>>>>>>>> side > > > >>>>>>>>>>>>>>>> note > > > >>>>>>>>>>>>>>>>>>>> for comparability, the current user defined > > > >>> functions > > > >>>> are > > > >>>>>>>>>>> all > > > >>>>>>>>>>>>>>>> temporary and > > > >>>>>>>>>>>>>>>>>>>> having no namespaces.) > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> Nevertheless, I can also see the merit of having > > > >>>>> namespaced > > > >>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>>>>>>> that can overwrite functions defined in a specific > > > >>>>> cat/db. > > > >>>>>>>>>>>>>> However, > > > >>>>>>>>>>>>>>>> this > > > >>>>>>>>>>>>>>>>>>>> idea appears orthogonal to the former and can be > > > >>> added > > > >>>>>>>>>>>>>>> incrementally. > > > >>>>>>>>>>>>>>>>>>>> How about we first implement non-namespaced temp > > > >>>>> functions > > > >>>>>>>>>>> now > > > >>>>>>>>>>>>> and > > > >>>>>>>>>>>>>>>> leave > > > >>>>>>>>>>>>>>>>>>>> the door open for namespaced ones for later > > > >>> releases as > > > >>>>> the > > > >>>>>>>>>>>>>>>> requirement > > > >>>>>>>>>>>>>>>>>>>> might become more crystal? This also helps shorten > > > >>> the > > > >>>>>>>>>>> debate > > > >>>>>>>>>>>>> and > > > >>>>>>>>>>>>>>>> allow us > > > >>>>>>>>>>>>>>>>>>>> to make some progress along this direction. > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> As to Dawid's idea of having a dedicated cat/db to > > > >>> host > > > >>>>> the > > > >>>>>>>>>>>>>>> temporary > > > >>>>>>>>>>>>>>>> temp > > > >>>>>>>>>>>>>>>>>>>> functions that don't have namespaces, my only > > > >>> concern > > > >>>> is > > > >>>>>>> the > > > >>>>>>>>>>>>>> special > > > >>>>>>>>>>>>>>>>>>>> treatment for a cat/db, which makes code less > > > >>> clean, as > > > >>>>>>>>>>>> evident > > > >>>>>>>>>>>>> in > > > >>>>>>>>>>>>>>>> treating > > > >>>>>>>>>>>>>>>>>>>> the built-in catalog currently. > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> Thanks, > > > >>>>>>>>>>>>>>>>>>>> Xuefiu > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> On Mon, Sep 16, 2019 at 5:07 PM Dawid Wysakowicz < > > > >>>>>>>>>>>>>>>>>>>> wysakowicz.da...@gmail.com> > > > >>>>>>>>>>>>>>>>>>>> wrote: > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> Hi, > > > >>>>>>>>>>>>>>>>>>>>> Another idea to consider on top of Timo's > > > >>> suggestion. > > > >>>>> How > > > >>>>>>>>>>>> about > > > >>>>>>>>>>>>>> we > > > >>>>>>>>>>>>>>>> have a > > > >>>>>>>>>>>>>>>>>>>>> special namespace (catalog + database) for > built-in > > > >>>>>>>>>>> objects? > > > >>>>>>>>>>>>> This > > > >>>>>>>>>>>>>>>> catalog > > > >>>>>>>>>>>>>>>>>>>>> would be invisible for users as Xuefu was > > > >>> suggesting. > > > >>>>>>>>>>>>>>>>>>>>> Then users could still override built-in > > > >>> functions, if > > > >>>>>>> they > > > >>>>>>>>>>>>> fully > > > >>>>>>>>>>>>>>>> qualify > > > >>>>>>>>>>>>>>>>>>>>> object with the built-in namespace, but by > default > > > >>> the > > > >>>>>>>>>>> common > > > >>>>>>>>>>>>>> logic > > > >>>>>>>>>>>>>>>> of > > > >>>>>>>>>>>>>>>>>>>>> current dB & cat would be used. > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> CREATE TEMPORARY FUNCTION func ... > > > >>>>>>>>>>>>>>>>>>>>> registers temporary function in current cat & dB > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> CREATE TEMPORARY FUNCTION cat.db.func ... > > > >>>>>>>>>>>>>>>>>>>>> registers temporary function in cat db > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> CREATE TEMPORARY FUNCTION system.system.func ... > > > >>>>>>>>>>>>>>>>>>>>> Overrides built-in function with temporary > function > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> The built-in/system namespace would not be > writable > > > >>>> for > > > >>>>>>>>>>>>> permanent > > > >>>>>>>>>>>>>>>>>>>> objects. > > > >>>>>>>>>>>>>>>>>>>>> WDYT? > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> This way I think we can have benefits of both > > > >>>> solutions. > > > >>>>>>>>>>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>>>>>>>>>> Dawid > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>> On Tue, 17 Sep 2019, 07:24 Timo Walther, < > > > >>>>>>>>>>> twal...@apache.org > > > >>>>>>>>>>>>>>> wrote: > > > >>>>>>>>>>>>>>>>>>>>>> Hi Bowen, > > > >>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>> I understand the potential benefit of overriding > > > >>>>> certain > > > >>>>>>>>>>>>>> built-in > > > >>>>>>>>>>>>>>>>>>>>>> functions. I'm open to such a feature if many > > > >>> people > > > >>>>>>>>>>> agree. > > > >>>>>>>>>>>>>>>> However, it > > > >>>>>>>>>>>>>>>>>>>>>> would be great to still support overriding > catalog > > > >>>>>>>>>>> functions > > > >>>>>>>>>>>>>> with > > > >>>>>>>>>>>>>>>>>>>>>> temporary functions in order to prototype a > query > > > >>>> even > > > >>>>>>>>>>>> though > > > >>>>>>>>>>>>> a > > > >>>>>>>>>>>>>>>>>>>>>> catalog/database might not be available > currently > > > >>> or > > > >>>>>>>>>>> should > > > >>>>>>>>>>>>> not > > > >>>>>>>>>>>>>> be > > > >>>>>>>>>>>>>>>>>>>>>> modified yet. How about we support both cases? > > > >>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>> CREATE TEMPORARY FUNCTION abs > > > >>>>>>>>>>>>>>>>>>>>>> -> creates/overrides a built-in function and > never > > > >>>>>>>>>>>> consideres > > > >>>>>>>>>>>>>>>> current > > > >>>>>>>>>>>>>>>>>>>>>> catalog and database; inconsistent with other > DDL > > > >>> but > > > >>>>>>>>>>>>> acceptable > > > >>>>>>>>>>>>>>> for > > > >>>>>>>>>>>>>>>>>>>>>> functions I guess. > > > >>>>>>>>>>>>>>>>>>>>>> CREATE TEMPORARY FUNCTION cat.db.fun > > > >>>>>>>>>>>>>>>>>>>>>> -> creates/overrides a catalog function > > > >>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>> Regarding "Flink don't have any other built-in > > > >>>> objects > > > >>>>>>>>>>>>> (tables, > > > >>>>>>>>>>>>>>>> views) > > > >>>>>>>>>>>>>>>>>>>>>> except functions", this might change in the near > > > >>>>> future. > > > >>>>>>>>>>>> Take > > > >>>>>>>>>>>>>>>>>>>>>> > https://issues.apache.org/jira/browse/FLINK-13900 > > > >>> as > > > >>>>> an > > > >>>>>>>>>>>>>> example. > > > >>>>>>>>>>>>>>>>>>>>>> Thanks, > > > >>>>>>>>>>>>>>>>>>>>>> Timo > > > >>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>> On 14.09.19 01:40, Bowen Li wrote: > > > >>>>>>>>>>>>>>>>>>>>>>> Hi Fabian, > > > >>>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>>> Yes, I agree 1-part/no-override is the least > > > >>>> favorable > > > >>>>>>>>>>>> thus I > > > >>>>>>>>>>>>>>>> didn't > > > >>>>>>>>>>>>>>>>>>>>>>> include that as a voting option, and the > > > >>> discussion > > > >>>> is > > > >>>>>>>>>>>> mainly > > > >>>>>>>>>>>>>>>> between > > > >>>>>>>>>>>>>>>>>>>>>>> 1-part/override builtin and 3-part/not override > > > >>>>> builtin. > > > >>>>>>>>>>>>>>>>>>>>>>> Re > However, it means that temp functions are > > > >>>>>>>>>>> differently > > > >>>>>>>>>>>>>>> treated > > > >>>>>>>>>>>>>>>>>>>> than > > > >>>>>>>>>>>>>>>>>>>>>>> other db objects. > > > >>>>>>>>>>>>>>>>>>>>>>> IMO, the treatment difference results from the > > > >>> fact > > > >>>>> that > > > >>>>>>>>>>>>>>> functions > > > >>>>>>>>>>>>>>>>>>>> are > > > >>>>>>>>>>>>>>>>>>>>> a > > > >>>>>>>>>>>>>>>>>>>>>>> bit different from other objects - Flink don't > > > >>> have > > > >>>>> any > > > >>>>>>>>>>>> other > > > >>>>>>>>>>>>>>>>>>>> built-in > > > >>>>>>>>>>>>>>>>>>>>>>> objects (tables, views) except functions. > > > >>>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>>>>> Cheers, > > > >>>>>>>>>>>>>>>>>>>>>>> Bowen > > > >>>>>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> -- > > > >>>>>>>>>>>>>>>>>>>> Xuefu Zhang > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>>>>> "In Honey We Trust!" > > > >>>>>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> -- > > > >>>>>>>>>>>>>>> Xuefu Zhang > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> "In Honey We Trust!" > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> -- > > > >>>>>>>>>>>>> Xuefu Zhang > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> "In Honey We Trust!" > > > >>>>>>>>>>>>> > > > >>>>>>>>>>> > > > >>>>>>>>>>> -- > > > >>>>>>>>>>> Xuefu Zhang > > > >>>>>>>>>>> > > > >>>>>>>>>>> "In Honey We Trust!" > > > >>>>>>>>>>> > > > >>>>>>>>> > > > > > > > > > > -- > > Xuefu Zhang > > > > "In Honey We Trust!" > > >
