👉 Rarities, in the context of data management and storage systems, refers to the rarest or least frequently accessed items within a collection. These are often used as a measure of storage efficiency and can be categorized into three categories:
1.
Least Frequent Items (LFIs)
: These are the most frequent items in a dataset that appear less than 5% of all records.
2.
Rarely Used Items (RUIs)
: These are the items that appear more frequently