Hi community,
I’m trying to extract column lineage from Flink SQL jobs (all of them are single INSERT statements). Here’s what I have done: 1. From `SqlToOperationConverter#convertSqlInsert()`, get the `PlannerQueryOperation` generated by the INSERT statement. 2. Get the corresponding `RelNode` by calling `PlannerQueryOperation#getCalciteTree()`, whose root is a `LogicalProject`. 3. Use the `RelMdColumnOrigins` metadata in Calcite to fetch column lineage, i.e. `relNode.getCluster.getMetadataQuery.getColumnOrigins(relNode, 1)` However, the column origins are always null or empty sets, which is quite confusing. Any suggestions on this would be appreciated. Many thanks~
