diff --git a/infra/airflow/scripts/generate_neo4j_graph_data.py b/infra/airflow/scripts/generate_neo4j_graph_data.py
index 0faafeb..dcf3176 100644
--- a/infra/airflow/scripts/generate_neo4j_graph_data.py
+++ b/infra/airflow/scripts/generate_neo4j_graph_data.py
@@ -88,6 +88,9 @@ def main():
                                    auth=(DB_USER, DB_PASSWORD))
     
     with driver.session() as session:
+        # Indexes make relationship MATCH/MERGE fast even with many existing nodes
+        session.run("CREATE INDEX product_id_idx IF NOT EXISTS FOR (p:Product) ON (p.product_id)")
+        session.run("CREATE INDEX supplier_id_idx IF NOT EXISTS FOR (s:Supplier) ON (s.supplier_id)")
         print(f"Generating {TARGET_NODES} product nodes...")
         print(f"Batch size: {BATCH_SIZE}")