> Let's not use TUMBLE (or HOP, or SESSION) as the main example. It is somewhat built-in (i.e. has special treatment in the code). Let's work in terms of, say, the RAMP user-defined function. It is used in several tests [1].
We may need to support all the user defined table functions with TABLE keyword left out. Are we planning to support it as a default syntax or as a dialect ? Say, maybe Oracle. Julian Hyde <[email protected]> 于2020年10月30日周五 上午5:11写道： > I think we can do them separately. And I think we should do the TABLE > first. The biggest problem is with namespaces - if you omit TABLE, you > have to deal with the possibility that there is a table (or view) > called FOO and also a parameterless table function called FOO. Not > sure how Oracle and SQL Server resolve this. > > Let's not use TUMBLE (or HOP, or SESSION) as the main example. It is > somewhat built-in (i.e. has special treatment in the code). Let's work > in terms of, say, the RAMP user-defined function. It is used in > several tests [1]. > > Julian > > [1] > https://github.com/apache/calcite/blob/ffc1e3b05e7f920d95c48f7c75fd48372684b8e7/core/src/test/java/org/apache/calcite/test/RelBuilderTest.java#L361 > > On Thu, Oct 29, 2020 at 1:53 PM Rui Wang <[email protected]> wrote: > > > > In terms of SQL grammar to support omitting TABLE, there are actually two > > changes for > > > > SELECT * > > FROM TABLE(TUMBLE(TABLE Bid, DESCRIPTOR(bidtime), INTERVAL '10' > MINUTES)); > > > > You can support omitting the TABLE after the FROM, which makes the query > > become: > > SELECT * > > FROM TUMBLE(TABLE Bid, DESCRIPTOR(bidtime), INTERVAL '10' MINUTES); > > > > Another is omitting TABLE from the parameter, which is > > SELECT * > > FROM TUMBLE(Bid, DESCRIPTOR(bidtime), INTERVAL '10' MINUTES); > > > > Do we want to achieve both or just one of these? If for one the grammar > is > > too complicated to change but for another the grammar is easier to be > > changed, are we ok to only have one keyword omitted? > > > > -Rui > > > > On Thu, Oct 29, 2020 at 11:28 AM Julian Hyde <[email protected]> wrote: > > > > > Can we drop the word "polymorphic" from the discussion? Polymorphic > > > table functions are a valid ask, but can be a separate discussion. > > > This is about calling table functions without the TABLE keyword, > > > right? > > > > > > Which is what I said to you four years ago: > > > https://issues.apache.org/jira/browse/CALCITE-1472#comment-15664799 > > > > > > In other words: let's fix > > > https://issues.apache.org/jira/browse/CALCITE-1490. > > > > > > Julian > > > > > > On Thu, Oct 29, 2020 at 2:26 AM Jark Wu <[email protected]> wrote: > > > > > > > > Hi all, > > > > > > > > It's great to see Calcite already supports PTF syntax and support the > > > > out-of-box new window syntax. > > > > > > > > SELECT * > > > > FROM TABLE(TUMBLE(TABLE Bid, DESCRIPTOR(bidtime), INTERVAL '10' > > > MINUTES)); > > > > > > > > However, some people from the Flink community think that the TABLE() > > > > keyword is a little verbose for users [5]. > > > > I have seen the discussion in the previous mailing list [1], and > know the > > > > TABLE() keyword is mandatory in SQL standard paper. > > > > > > > > But it seems that other databases are not following the standard, I > find > > > > that Polymorphic Table Function syntax > > > > in Oracle is more concise without the TABLE() keywords [2][3], e.g. > > > > > > > > SELECT * > > > > FROM skip_col(scott.emp, COLUMNS(comm, hiredate, mgr)) > > > > > > > > Besides, SQL Server also seems to support the non TABLE() syntax for > > > > table-valued functions [4]. > > > > If we can support the Oracle syntax, it would be more consistent with > > > > existing TUMBLE functions > > > > and hence easier to be picked up by users. > > > > > > > > The new window TVF syntax can be: > > > > > > > > SELECT window_start, count(*) > > > > FROM TUMBLE(Bid, COLUMNS(bidtime), INTERVAL '10' MINUTES)) > > > > GROUP BY window_start; > > > > > > > > Which is more similar to the existing group window functions: > > > > > > > > SELECT TUMBLE_START(bidtime, INTERVAL '10' MINUTES), count(*) > > > > FROM Bid > > > > GROUP BY TUMBLE(bidtime, INTERVAL '10' MINUTES); > > > > > > > > I am fairly inexperienced with the parsing and validation logic in > > > Calcite, > > > > so I don't know whether the new syntax can be supported in Calcite. > > > > > > > > What do you think? > > > > > > > > Best, > > > > Jark > > > > > > > > [1]: > > > > > > > > https://lists.apache.org/x/thread.html/4a91632b1c780ef9d67311f90fce626582faae7d30a134a768c3d324@%3Cdev.calcite.apache.org%3E > > > > [2]: > > > https://oracle-base.com/articles/18c/polymorphic-table-functions-18c > > > > [3]: > > > > > > > > https://docs.oracle.com/en/database/oracle/oracle-database/18/lnpls/plsql-optimization-and-tuning.html#GUID-F8E13DDD-710D-4626-824E-B344849C5AFE > > > > [4]: > > > > > > > > https://www.sqlservertutorial.net/sql-server-user-defined-functions/sql-server-table-valued-functions/ > > > > [5]: > > > > > > > > http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-145-Support-SQL-windowing-table-valued-function-tp45269p45665.html > > > >
