diff --git a/src/optimizer/optimizer.cpp b/src/optimizer/optimizer.cpp
index d795b1c6dde..da4d1d1cd12 100644
--- a/src/optimizer/optimizer.cpp
+++ b/src/optimizer/optimizer.cpp
@@ -12,7 +12,7 @@ namespace kuzu {
 namespace optimizer {
 
 void Optimizer::optimize(planner::LogicalPlan* plan) {
-    auto a = plan->toString();
+
     // Factorization structure should be removed before further optimization can be applied.
     auto removeFactorizationRewriter = RemoveFactorizationRewriter();
     removeFactorizationRewriter.rewrite(plan);
@@ -22,14 +22,14 @@ void Optimizer::optimize(planner::LogicalPlan* plan) {
 
     auto filterPushDownOptimizer = FilterPushDownOptimizer();
     filterPushDownOptimizer.rewrite(plan);
-    a = plan->toString();
+
     auto projectionPushDownOptimizer = ProjectionPushDownOptimizer();
     projectionPushDownOptimizer.rewrite(plan);
-    a = plan->toString();
+
     // HashJoinSIPOptimizer should be applied after optimizers that manipulate hash join.
     auto hashJoinSIPOptimizer = HashJoinSIPOptimizer();
     hashJoinSIPOptimizer.rewrite(plan);
-    a = plan->toString();
+
     auto factorizationRewriter = FactorizationRewriter();
     factorizationRewriter.rewrite(plan);
 
diff --git a/src/planner/query_planner.cpp b/src/planner/query_planner.cpp
index 063786121fc..5ea07cbfb06 100644
--- a/src/planner/query_planner.cpp
+++ b/src/planner/query_planner.cpp
@@ -189,8 +189,6 @@ void QueryPlanner::planOptionalMatch(const QueryGraphCollection& queryGraphColle
         auto plan = planJoins(queryGraphCollection, predicates);
         leftPlan.setLastOperator(plan->getLastOperator());
         appendAccumulate(AccumulateType::OPTIONAL, leftPlan);
-        auto s = leftPlan.toString();
-        auto b = 1;
         return;
     }
     auto correlatedExpressions =
diff --git a/test/test_files/tinysnb/subquery/exists.test b/test/test_files/tinysnb/subquery/exists.test
index f4e7be7c94c..3da8ff04897 100644
--- a/test/test_files/tinysnb/subquery/exists.test
+++ b/test/test_files/tinysnb/subquery/exists.test
@@ -5,7 +5,6 @@
 
 -CASE SubqueryExists
 
-
 -LOG ExistSubqueryTest
 -STATEMENT MATCH (a:person) WHERE EXISTS { MATCH (a)-[:knows]->(b:person) } RETURN COUNT(*)
 -ENUMERATE
@@ -87,5 +86,3 @@ Bob
 Carol
 Dan
 Elizabeth
-
-