Function assign_work_table

datafusion/physical-plan/src/recursive_query.rs:388–410

(
    plan: Arc<dyn ExecutionPlan>,
    work_table: &Arc<WorkTable>,
)

}

fn assign_work_table(
    plan: Arc<dyn ExecutionPlan>,
    work_table: &Arc<WorkTable>,
) -> Result<Arc<dyn ExecutionPlan>> {
    let mut work_table_refs = 0;
    plan.transform_down(|plan| {
        if let Some(new_plan) =
            plan.with_new_state(Arc::clone(work_table) as Arc<dyn Any + Send + Sync>)
        {
            if work_table_refs > 0 {
                not_impl_err!(
                    "Multiple recursive references to the same CTE are not supported"
                )
            } else {
                work_table_refs += 1;
                Ok(Transformed::yes(new_plan))
            }
        } else {
            Ok(Transformed::no(plan))
        }
    })
    .data()
}

impl Stream for RecursiveQueryStream {
    type Item = Result<RecordBatch>;