diff --git a/plan/column_pruning.go b/plan/column_pruning.go
index <HASH>..<HASH> 100644
--- a/plan/column_pruning.go
+++ b/plan/column_pruning.go
@@ -165,10 +165,6 @@ func (ds *DataSource) PruneColumns(parentUsedCols []*expression.Column) {
 }
 
 // PruneColumns implements LogicalPlan interface.
-func (p *LogicalTableDual) PruneColumns(_ []*expression.Column) {
-}
-
-// PruneColumns implements LogicalPlan interface.
 func (p *LogicalExists) PruneColumns(parentUsedCols []*expression.Column) {
 	p.children[0].PruneColumns(nil)
 }
plan: remove unneeded lines of code (#<I>)