pub fn build_streaming_pipeline_with_policy<'a, 'txn: 'a, S: KVStore + 'txn, C: Catalog + ?Sized, T: SqlTxn<'txn, S>>(
txn: &'a mut T,
catalog: &C,
plan: LogicalPlan,
memory: Option<&MemoryPolicy>,
) -> Result<(Box<dyn RowIterator + 'a>, Projection, Vec<ColumnMetadata>)>