Which best describes a skinny table in Salesforce?

A skinny table in Salesforce refers to a custom table that is designed to enhance performance by containing a limited set of fields from a standard or custom object. By including only the most frequently accessed fields, skinny tables reduce the amount of data that needs to be queried, which results in faster read operations. This is particularly useful for large datasets where retrieving only essential information can significantly improve performance.

Skinny tables are created specifically for this purpose and do not include all fields of the original object. This characteristic allows Salesforce to optimize indexing and retrieval times, making it easier for applications to handle high volumes of data efficiently. The other options—such as containing all fields of an object, being unmodifiable, or being used for temporary data storage—do not accurately capture the primary function and design of skinny tables.