Il ven 17 nov 2017, 19:19 Julian Hyde <jh...@apache.org> ha scritto:
> > IMHO It would better to keep somethin like an EnumerableProjection which
> > renames the fields
>
> I disagree. If we commit to preserving field names all kinds of
> optimization are not possible.
>
> In Calcite RelNode world, field names are a hint to make debugging
> easier but are not ultimately reliable. The reliable way to reference
> fields is by position.
>
I understand your point Julian. In my case I want the final resultset to
have knowledge of the alias requested by the user.
Select a as b from table
ResultSet rs = ...
String col = rs.getString("b");
If I am losing the alias I can't support this case.
The test case from Luis is working so there is some trick I am missing
Enrico
> Julian
>
>
> On Fri, Nov 17, 2017 at 9:33 AM, Enrico Olivelli <eolive...@gmail.com>
> wrote:
> > I run the debugger on your test case.
> > IMHO The BindableTableScan RelNode does not keep the original aliases of
> > the query.
> > The test cases runs CalciteConnection, maybe there is some magic during
> the
> > execution of the query.
> > Can you provide me some insight ?
> > Maybe it is better that I provide a reproducer.
> > I am not using CalciteConnection but only the planner
> >
> > Thanks
> > Enrico
> >
> > 2017-11-17 18:08 GMT+01:00 Enrico Olivelli <eolive...@gmail.com>:
> >
> >> your test is working
> >>
> >> I will try to understand where is the problem in my code
> >>
> >> b.q. I am looking for a sponsor for this patch, which is a real blocker
> >> for me, could you pleas take a look Luis ?
> >> https://github.com/apache/calcite/pull/568
> >>
> >> Thank you
> >> Enrico
> >>
> >> 2017-11-17 17:45 GMT+01:00 Luis Fernando Kauer <
> >> lfka...@yahoo.com.br.invalid>:
> >>
> >>> Please insert the following test in ScannableTableTest and run:
> >>> /** ProjectableFilterableTable project push down using alias. */
> >>> @Test public void testPFPushDownWithAlias() throws Exception {
> >>> final StringBuilder buf = new StringBuilder();
> >>> final Table table = new BeatlesProjectableFilterableTable(buf,
> true);
> >>> CalciteAssert.that()
> >>> .with(newSchema("s", "beatles", table))
> >>> .query("select \"i\" as theKey from \"s\".\"beatles\"")
> >>> .explainContains("EnumerableInterpreter\n"
> >>> + " BindableTableScan(table=[[s, beatles]],
> >>> projects=[[0]])\n")
> >>> .returnsUnordered("THEKEY=4",
> >>> "THEKEY=4",
> >>> "THEKEY=6",
> >>> "THEKEY=5"); }
> >>> It passes for me.
> >>> You'll need the updated version of this test class, because it was
> >>> recently refactored.
> >>> It's usually easier for other people to test the problem if you create
> >>> runnable test cases to show the problem. Em sexta-feira, 17 de
> novembro
> >>> de 2017 14:29:09 BRST, Enrico Olivelli <eolive...@gmail.com> escreveu:
> >>>
> >>> In the RowType I have 'k1' and not "thekey"
> >>>
> >>> Enrico
> >>>
> >>> 2017-11-17 17:20 GMT+01:00 Luis Fernando Kauer
> >>> <lfka...@yahoo.com.br.invalid
> >>> >:
> >>>
> >>> > Did you execute the query?
> >>> > ProjectRemoveRule removes the Project when it is "trivial". Since
> the
> >>> > only used project was pushed to BindableTableScan, the Project would
> >>> only
> >>> > set the alias, but that can be done in row type.
> >>> > The result is correct because RowType is preserved with the alias.
> It
> >>> > just does not show in the plan.
> >>> > However, I seems that repeating a column with different aliases
> >>> generates
> >>> > an error:
> >>> > SELECT k1 theKey, k1 theKey2 FROM tblspace1.tsql where k1 ='mykey2'
> >>> >
> >>> > Regards,
> >>> > Luis Fernando
> >>> >
> >>> > Em sexta-feira, 17 de novembro de 2017 12:27:49 BRST, Enrico
> >>> Olivelli <
> >>> > eolive...@gmail.com> escreveu:
> >>> >
> >>> > Hi,
> >>> > I have a ProjectableFilterableTable, it seems to me that the
> >>> BindablaScan
> >>> > RelNode does not keep track of column name aliases in the original
> >>> > projection
> >>> >
> >>> > Example:
> >>> >
> >>> > Query:SELECT k1 theKey FROM tblspace1.tsql where k1 ='mykey2'
> >>> >
> >>> > -- Logical Plan
> >>> > LogicalProject(THEKEY=[$0])
> >>> > LogicalFilter(condition=[=($0, 'mykey2')])
> >>> > EnumerableTableScan(table=[[tblspace1, tsql]])
> >>> >
> >>> > -- Best Plan
> >>> > EnumerableInterpreter
> >>> > BindableTableScan(table=[[tblspace1, tsql]], filters=[[=($0,
> >>> > 'mykey2')]],
> >>> > projects=[[0]])
> >>> >
> >>> > Is this correct ?
> >>> > IMHO It would better to keep somethin like an EnumerableProjection
> which
> >>> > renames the fields
> >>> >
> >>> > Am I missing something ?
> >>> > Thanks
> >>> > Enrico
> >>> >
> >>> >
> >>>
> >>>
> >>
> >>
>
--
-- Enrico Olivelli
