When there is a large set of data and you want to retrieve a small set of data. What is the concept called?

When there is a large set of data and you want to retrieve a small set

1.	When there is a large set of data and you want to retrieve a small set of data. What is the concept called?
Answer» When there is a LARGE SET of data and you want to retrieve a small set of data. What is the CONCEPT called? Choose the correct option from below list (1)BUCKETING (2)Partitioning (3)None of the options (4)Data Sampling Answer:-(4)Data Sampling