Query optimization is one of the key factors affecting the performance of database systems that aim to enact the query execution plan with minimum cost. Particularly in distributed database systems. due to the multiple copies of the data that are stored in different data nodes. resulting in the dramatic increase in the feasible query execution plans for a query statement. https://safeersappliancers.shop/product-category/siemens-ki86saf30g-iq-500-integrated-70-30-fridge-freezer-a/