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 |
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.
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;