Dimension Table Cardinality Statistics
For LT/ST-J2a (Reasonable Unindexed) join example, the following row information is given for the small tables:
| Attribute | Cardinality (rows) |
|---|---|
| Color | 3 |
| Size | 10 |
| Options | 10 |
Fact Table Uniqueness Statistics
The following statistics information is given for the large table:
| Column Name | Number of Unique Values |
|---|---|
| color | 6 |
| size | 30 |
| options | 300 |
No index is created on the collection of join columns (color, size, and options) of the large table.
Test Query
The following query is used for the LT/ST-J2a (Reasonable Unindexed) join in this example:
SELECT * FROM widget, color, size, options WHERE widgets.color=color.code AND widgets.size=size.code AND widgets.options=options.code AND size.description=options.description;