What does a Subset Ratio indicate in a data model?

A Subset Ratio in a data model is a metric that signifies the relationship between distinct values present in a particular table and how those values correspond to the entire model. It essentially reflects how many unique values from a specified table can be found when considering the total unique values across all tables in the data model.

When analyzing data relationships, understanding the distinct values in a single table can provide insights into the level of granularity and uniqueness of data captured in that table. The subset ratio thus helps in assessing data quality, potential duplications, and the efficiency of joins within the data model.

The other options do not accurately describe the function of the subset ratio. While the size of a table or rows may be relevant for performance, they do not relate to the correlation or distinctness of values. Similarly, counting keys in a model provides a different measure of complexity but does not address the ratio aspect concerning distinct values and their relationship to the entire dataset.