Hi all, I'm trying to extract all of the (fully qualified) columns used by a query - similar to the information provided by RelMetadataQuery.getTableReferences() <https://calcite.apache.org/apidocs/org/apache/calcite/rel/metadata/RelMetadataQuery.html#getTableReferences-org.apache.calcite.rel.RelNode->, but for column references. Is this possible to do using Calcite?
I've been looking through the API docs and experimenting with the API, but I haven't found a straightforward way of doing this. Any help or information is appreciated. Adam
