Hi org.apache.calcite.rel.metadata.RelMetadataQuery#getColumnOrigins may help
Regards! Aron Tao James Daniel <[email protected]> 于2021年5月19日周三 上午12:35写道： > 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: > > LogicalProject([...]) > LogicalJoin(condition=[=($0, $4)], joinType=[inner]) > LogicalTableScan(table=[[DB, R]]) > LogicalAggregate(group=[{0}], agg#0=[MIN($1)]) > LogicalProject(a=[$3], $f0=[true]) > 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 >
