text: use('contactData');
  
  // Insert two documents in 'customer' collection
  db.customers.insertMany([{ name: 'Momchil', age: 37, salary: 3000 }, { name: 'Angelina', age: 29, salary: 3500 }]);
  
  // Create an index
  db.customers.createIndex({ name: 1 });
  
  // Check the result
  db.customers.explain('executionStats').find({ name: 'Momchil' });
  
  // Return without id and only names
  db.customers.explain('executionStats').find({ name: 'Momchil' }, { _id: 0, name: 1 });