??????Tracking column's origin

[953396112]

Hi James:
1) I guess you want to trace the column's origin in original table. In Calcite, 
we can use `RelMetadatauery.getColumnOrigin()` to trace the column's origin.The 
method tracks the origin of columns.Here is a unit test 
'org.apache.calcite.test.RelMetadataTest#testCalcColumnOriginsTable' for your 
reference.
2) After removing a specific operator, the column reference of the parent 
operator will be affected. It seems that no tool class can do this. Generally 
speaking, I will traverse to a specific operator pattern to modify the related 
column reference and generate a new RelNode. Maybe we use `RelOptRule` or 
`RelShuttle` to do this.
  I hope it can help you.
  Xu




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??????:                                                                         
                                               "dev"                            
                                                        
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????:&nbsp;Tracking column's origin



Hi, all.
I am trying to rewrite the query plan by removing some nodes but faced with
issues related to manipulating column ref indexes.

Let's consider the following calcite plan:

&nbsp; LogicalProject([...])
&nbsp;&nbsp;&nbsp; LogicalJoin(condition=[=($0, $4)], joinType=[inner])
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LogicalTableScan(table=[[DB, R]])
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LogicalAggregate(group=[{0}], agg#0=[MIN($1)])
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LogicalProject(a=[$3], $f0=[true])
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
LogicalTableScan(table=[[DB, S]])


In the join condition =($0, $4), the RHS column ref $4 is actually coming
from the $3 of table S.
To know this, we track down few nodes in the tree starting from the RHS
child of the join node.
But it becomes tricky when we use a more complex situation.
1) So, I wonder is there a utility class or method to support this purpose?

Furthermore, when we remove LogicalProject(a=[$3], $f0=[true]), we have to
manipulate all related column ref index starting from a parent of that
project node to the root node but manually tracking and shifting column ref
index is really a matter due to its complexity.
2) So I wonder the current Calcite impl has a utility class or methods to
help this situation.

3) Also, would you give me some general guidelines for implementing this
kind of stuff in Calcite?

Thanks,
James