As a database administrator, you are in charge of regularly tuning the performance of the system. After a long period of operation, you noticed that queries making use of a specific file start to slow down. This particular file used to be sorted but is not anymore. After examining the type of queries processed on the file, you decided that sorting the query would improve its speed. Given that there is a B+ tree index on the file with the same search key, you know you have two options:

Retrieving the records in order through the index.

Retrieving the records in random order and then sorting them.

Compare the estimated cost of the two approaches to figure out which one is better to use.