Substrait consumer doesn't respect final output column names #10817
Description
Describe the bug
Substrait doesn't support the concept of ALIASes, as inside the plan there are no column names, just indices (https://substrait.io/expressions/field_references/#field-references). Ensuring the final plan has the right column names is done through the "names" field on the RootRel.
DataFusion supports already producing that "names" field (
), though the produced list lacks the inner names of struct fields (the "names" should be a flattened list of a depth-first search through all the fields). However the consumer side completely disregards the given names ( ).To Reproduce
#[tokio::test]
async fn select_with_alias() -> Result<()> {
roundtrip("SELECT a AS aliased_a FROM data").await
}
fails with
assertion `left == right` failed
left: "Projection: data.a AS aliased_a\n TableScan: data projection=[a]"
right: "TableScan: data projection=[a]"
Expected behavior
Should succeed producing the correct column names
Additional context
I'll write up a PR to fix