Rename Expr::display_name to Expr::schema_name, make UNNEST naming conform to convention

datafusion/core/src/physical_planner.rs

@@ -1529,7 +1529,7 @@ pub fn create_window_expr(
     // unpack aliased logical expressions, e.g. "sum(col) over () as total"
     let (name, e) = match e {
         Expr::Alias(Alias { expr, name, .. }) => (name.clone(), expr.as_ref()),
-        _ => (e.display_name()?, e),
+        _ => (e.schema_name()?, e),
     };
     create_window_expr_with_name(e, name, logical_schema, execution_props)
 }
@@ -1620,7 +1620,7 @@ pub fn create_aggregate_expr_and_maybe_filter(
     // unpack (nested) aliased logical expressions, e.g. "sum(col) as total"
     let (name, e) = match e {
         Expr::Alias(Alias { expr, name, .. }) => (Some(name.clone()), expr.as_ref()),
-        Expr::AggregateFunction(_) => (e.display_name().ok(), e),
+        Expr::AggregateFunction(_) => (e.schema_name().ok(), e),
         _ => (None, e),
     };