Minor: remove unused methods in datafusion/optimizer/src/utils.rs (#5098

)

datafusion/optimizer/src/utils.rs

@@ -24,7 +24,7 @@ use datafusion_expr::expr::{BinaryExpr, Sort};
 use datafusion_expr::expr_rewriter::{ExprRewritable, ExprRewriter};
 use datafusion_expr::expr_visitor::inspect_expr_pre;
 use datafusion_expr::{
-    and, col,
+    and,
     logical_plan::{Filter, LogicalPlan},
     utils::from_plan,
     Expr, Operator,
@@ -412,60 +412,6 @@ pub fn only_or_err<T>(slice: &[T]) -> Result<&T> {
     }
 }
 
-/// Merge and deduplicate two sets Column slices
-///
-/// # Arguments
-///
-/// * `a` - A tuple of slices of Columns
-/// * `b` - A tuple of slices of Columns
-///
-/// # Return value
-///
-/// The deduplicated union of the two slices
-pub fn merge_cols(
-    a: (&[Column], &[Column]),
-    b: (&[Column], &[Column]),
-) -> (Vec<Column>, Vec<Column>) {
-    let e =
-        a.0.iter()
-            .map(|it| it.flat_name())
-            .chain(a.1.iter().map(|it| it.flat_name()))
-            .map(|it| Column::from(it.as_str()));
-    let f =
-        b.0.iter()
-            .map(|it| it.flat_name())
-            .chain(b.1.iter().map(|it| it.flat_name()))
-            .map(|it| Column::from(it.as_str()));
-    let mut g = e.zip(f).collect::<Vec<_>>();
-    g.dedup();
-    g.into_iter().unzip()
-}
-
-/// Change the relation on a slice of Columns
-///
-/// # Arguments
-///
-/// * `new_table` - The table/relation for the new columns
-/// * `cols` - A slice of Columns
-///
-/// # Return value
-///
-/// A new slice of columns, now belonging to the new table
-pub fn swap_table(new_table: &str, cols: &[Column]) -> Vec<Column> {
-    cols.iter()
-        .map(|it| Column {
-            relation: Some(new_table.to_string()),
-            name: it.name.clone(),
-        })
-        .collect()
-}
-
-pub fn alias_cols(cols: &[Column]) -> Vec<Expr> {
-    cols.iter()
-        .map(|it| col(it.flat_name().as_str()).alias(it.name.as_str()))
-        .collect()
-}
-
 /// Rewrites `expr` using `rewriter`, ensuring that the output has the
 /// same name as `expr` prior to rewrite, adding an alias if necessary.
 ///