In what circumstance would you use the NODUPKEY option?

The NODUPKEY option is specifically designed to address situations where you want to eliminate duplicate records based on key variables in a dataset. When this option is used, SAS examines the designated key variables and keeps only the first occurrence of each unique combination, essentially filtering out any subsequent duplicate rows. This is particularly useful in data processing tasks where maintaining distinct records is essential for analysis, such as when preparing data for reporting or statistical modeling.

In scenarios involving graphs, the need to remove duplicates based on key variables does not apply directly, as the focus there is on visual representation rather than on data integrity regarding duplicates. Additionally, wanting to keep duplicate records contradicts the purpose of using NODUPKEY, as its primary function is to purge duplicates. In the context of merging datasets, while handling duplicates may become relevant, the NODUPKEY option is not specifically tied to the merging process itself but rather to the unique identification of records within a dataset. Thus, the circumstance in which NODUPKEY is most appropriately applied is indeed when removing duplicates based on key variables.