RatingTable Schema
The table has user ratings of items.
| Column | Data Type | Description |
|---|---|---|
| userid_column | INTEGER | User identifier. |
| itemid_column | INTEGER | Item identifier. |
| rating_column | Any numeric type. | Rating user gave item. |
If the same user rates the same item more than once, the function might select any one of those ratings for that user-item combination; therefore, function results are nondeterministic even with the UniqueID argument.