Sorry for late reply because we were in a vocation holiday. @Julian
> Thanks for the examples. The PARTITION BY syntax is a clear improvement > for the SESSION function and I think we should do it, even though it is > breaking. Thanks for great suggestion. I’ll make further comments against > https://issues.apache.org/jira/browse/CALCITE-4337 < > https://issues.apache.org/jira/browse/CALCITE-4337> > The further comments in JIRA is great and very professional. I need double check in the SQL standard for some points. Once I finish it, I would reply in the JIRA as soon as possible. @Viliam > the table argument, according to the sql standard, must be in > parentheses, like this: > > SELECT * > FROM TABLE(SESSION(TABLE(input_table), ... > Good point, I would keep it in mind. Best, JING ZHANG Viliam Durina <[email protected]> 于2021年10月3日周日 上午2:21写道： > Btw, the table argument, according to the sql standard, must be in > parentheses, like this: > > SELECT * > FROM TABLE(SESSION(TABLE(input_table), ... > > When doing a breaking change, we should also consider this. > > Viliam > > On Thu, 30 Sept 2021 at 18:11, Julian Hyde <[email protected]> wrote: > > > Thanks for the examples. The PARTITION BY syntax is a clear improvement > > for the SESSION function and I think we should do it, even though it is > > breaking. > > > > I’ll make further comments against > > https://issues.apache.org/jira/browse/CALCITE-4337 < > > https://issues.apache.org/jira/browse/CALCITE-4337>. > > > > > On Sep 29, 2021, at 9:58 PM, JING ZHANG <[email protected]> wrote: > > > > > > Hi Julian, > > > Thanks for your feedback, the suggestion is very helpful. > > > I've added the discussion content the CALCITE-4337 > > > <https://issues.apache.org/jira/browse/CALCITE-4337> [1]. I would > > continue > > > later discussion in the JIRA case. > > > About an example of a query before and after the syntax change. I would > > use > > > the example in session table function document > > > <https://calcite.apache.org/docs/reference.html#session> [2]. > > > Old syntax demo: > > > > > >> SELECT * FROM TABLE( SESSION( TABLE orders, DESCRIPTOR(rowtime), > > >> DESCRIPTOR(product), INTERVAL '20' MINUTE)); -- or with the named > > params -- > > >> note: the DATA param must be the first SELECT * FROM TABLE( SESSION( > > DATA > > >> => TABLE orders, TIMECOL => DESCRIPTOR(rowtime), KEY => > > DESCRIPTOR(product > > >> ), SIZE => INTERVAL '20' MINUTE)); > > > > > > > > > New syntax demo is as follows, the difference is use PARTITION BY > clause > > to > > > replace KEY DESCRIPTOR. > > > > > >> SELECT * FROM TABLE( SESSION( TABLE orders PARTITION BY product, > > >> DESCRIPTOR(rowtime), INTERVAL '20' MINUTE)); -- or with the named > > params -- > > >> note: the DATA param must be the first SELECT * FROM TABLE( SESSION( > > DATA > > >> => TABLE orders PARTITION BY product, TIMECOL => DESCRIPTOR(rowtime), > > SIZE > > >> => INTERVAL '20' MINUTE)); > > > > > > > > > Best, > > > JING ZHANG > > > > > > Julian Hyde <[email protected]> 于2021年9月30日周四 上午4:55写道： > > > > > >> Regarding changes to the syntax of the SESSION table function. I am > open > > >> to this, even though it would be a breaking change. Can you give an > > example > > >> of a query before and after the syntax change? > > >> > > >> I would like to support the new PARTITIONED BY clause for table > > functions. > > >> I encourage you to make the change for table functions in general, > > before > > >> and separately from the change to the SESSION function and window > > functions. > > >> > > >> Please ensure that the discussion gets added to the JIRA case. It > might > > be > > >> best if we continue discussion in the JIRA case. > > >> > > >> Julian > > >> > > >> > > >>> On Sep 28, 2021, at 10:28 PM, JING ZHANG <[email protected]> > wrote: > > >>> > > >>> Hi community, > > >>> I'm now working on CALCITE-4337 > > >>> <https://issues.apache.org/jira/browse/CALCITE-4337> [1] which aims > to > > >>> support PARTITION BY clause for table function argument. > > >>> I've submitted a pull request > > >>> <https://github.com/apache/calcite/pull/2524> [2], > > >>> thanks @Danny very much for review. > > >>> There are two points left which need more discussion. So I fire this > > >>> discussion in order to get more broader suggestions. > > >>> 1. SQL standard Polymorphic Table Functions > > >>> < > > >> > > > https://standards.iso.org/ittf/PubliclyAvailableStandards/c069776_ISO_IEC_TR_19075-7_2017.zip > > >>> > > >>> [3] > > >>> states: > > >>> > > >>>> Input tables have either row semantics or set semantics, as follows: > > >>>> a) Row semantics means that the the result of the PTF is decided on > a > > >>>> row-by-row basis. As an extreme example, the DBMS could atomize the > > >> input > > >>>> table into individual rows, and send each single row to a different > > >> virtual > > >>>> processor. > > >>>> b) Set semantics means that the outcome of the function depends on > how > > >> the > > >>>> data is partitioned. A partition may not be split across virtual > > >>>> processors, nor may a virtual processor handle more than one > > partition. > > >>> > > >>> > > >>> A SESSION window has an input table with set semantics which means it > > >>> requires a PARTITION BY clause. > > >>> The new syntax is conflict with current session window table function > > >>> syntax, please take a look at session table function > > >>> <https://calcite.apache.org/docs/reference.html#session> [4]. > > >>> *Could we replace the old syntax directly, or take compatible into > > >>> consideration.* > > >>> 2. Based on SQL standard, only input tables with set semantics may be > > >>> partitioned while input table with row semantics may not be > > partitioned. > > >>> *Should we have separate branch in Parser.jj for set semantic input > > table > > >>> of table function(Currently, only input table of session window table > > >>> function has set semantics)*? > > >>> > > >>> Any suggestion is appreciated. Thanks in advanced. > > >>> [1] https://issues.apache.org/jira/browse/CALCITE-4337 > > >>> [2] https://github.com/apache/calcite/pull/2524 > > >>> [3] > > >>> > > >> > > > https://standards.iso.org/ittf/PubliclyAvailableStandards/c069776_ISO_IEC_TR_19075-7_2017.zip > > >>> [4] https://calcite.apache.org/docs/reference.html#session > > >>> > > >>> Best > > >>> JING ZHANG > > >> > > >> > > > > > > -- > This message contains confidential information and is intended only for > the > individuals named. If you are not the named addressee you should not > disseminate, distribute or copy this e-mail. Please notify the sender > immediately by e-mail if you have received this e-mail by mistake and > delete this e-mail from your system. E-mail transmission cannot be > guaranteed to be secure or error-free as information could be intercepted, > corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. > The sender therefore does not accept liability for any errors or omissions > in the contents of this message, which arise as a result of e-mail > transmission. If verification is required, please request a hard-copy > version. -Hazelcast >
