Can not plan left join query on 2 inline datasources

[suneet-s]

Affected Version

0.19.0

Description

Found while investigating #9792

with abc as
(
  SELECT cityName, "__time", sum_added from wikipedia WHERE "cityName" = 'Buenos Aires'
)
SELECT t1.cityName, t1."__time" from abc as t1 LEFT join abc as t2 on t1.cityName = t2.cityName WHERE t1.cityName = 'Buenos Aires'

This fails with the error

org.apache.calcite.plan.RelOptPlanner$CannotPlanException: There are not enough rules to produce a node with desired properties: convention=DRUID, sort=[].
Missing conversion is LogicalSort[convention: NONE -> DRUID]
There is 1 empty subset: rel#10934:Subset#8.DRUID.[], the relevant part of the original plan is as follows
10932:LogicalSort(fetch=[100])
  10930:LogicalProject(subset=[rel#10931:Subset#7.NONE.[]], cityName=[CAST('Buenos Aires':VARCHAR):VARCHAR], __time=[$1])
    10928:LogicalJoin(subset=[rel#10929:Subset#6.NONE.[]], condition=[=($0, 'Buenos Aires')], joinType=[left])
      10922:LogicalProject(subset=[rel#10923:Subset#3.NONE.[]], cityName=[CAST('Buenos Aires':VARCHAR):VARCHAR], __time=[$0])
        10920:LogicalFilter(subset=[rel#10921:Subset#2.NONE.[]], condition=[=($1, 'Buenos Aires')])
          10918:LogicalProject(subset=[rel#10919:Subset#1.NONE.[]], __time=[$0], cityName=[$2])
            10859:LogicalTableScan(subset=[rel#10917:Subset#0.NONE.[]], table=[[druid, wikipedia]])
      10926:LogicalFilter(subset=[rel#10927:Subset#5.NONE.[]], condition=[=($0, 'Buenos Aires')])
        10924:LogicalProject(subset=[rel#10925:Subset#4.NONE.[]], cityName=[$2])
          10859:LogicalTableScan(subset=[rel#10917:Subset#0.NONE.[]], table=[[druid, wikipedia]])

However, the same query as an inner join works

with abc as
(
  SELECT cityName, "__time", sum_added from wikipedia WHERE "cityName" = 'Buenos Aires'
)
SELECT t1.cityName, t1."__time" from abc as t1 inner join abc as t2 on t1.cityName = t2.cityName WHERE t1.cityName = 'Buenos Aires'

The query also works if a time filter is added

with abc as
(
  SELECT cityName, "__time", sum_added from wikipedia WHERE "cityName" = 'Buenos Aires' and "__time" > '2016'
)
SELECT t1.cityName, t1."__time" from abc as t1 left join abc as t2 on t1.cityName = t2.cityName WHERE t1.cityName = 'Buenos Aires'

[suneet-s]

This appears to work when as long as there is a filter that is on a column which is not part of the join condition.

For example

with abc as
(
  SELECT cityName, "__time", sum_added from wikipedia WHERE "cityName" = 'Buenos Aires'
)
SELECT t1.cityName, t1."__time" from abc as t1 LEFT join abc as t2 on t1.sum_added = t2.sum_added