Test: Quiz: Cartesian Product and the Join Operations
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.
1. If table A have 10 rows and table B have 5 rows, how many rows will be returned if you perform a equi-join on those two tables? Mark for Review
It depends on the data found in the two tables. (*)
2. Oracle proprietary JOINS can use the WHERE clause for conditions other than the join-condition. True or False? Mark for Review
3. Will the following statement work?
SELECT department_name, last_name
FROM employees, departments
WHERE department_id = department_id; Mark for Review
Yes, there are no syntax errors in the statement.
No, Oracle will return a column ambiguously defined error. (*)
Yes, Oracle will resolve which department_id colum comes from which table.
No, Oracle will not allow joins in the WHERE clause.
4. What is the result of a query that selects from two tables but includes no join condition? Mark for Review
A Cartesian product. (*)
A selection of matched rows from both tables.
A Syntax error.
A selection of rows from the first table only.
5. When must column names be prefixed by table names in JOIN syntax? Mark for Review
When more than two tables participate in the join.
Only when query speed and database performance is a concern.
When the same column name appears in more than one table of the query. (*)
6. If table A have 10 rows and table B have 5 rows, how many rows will be returned if you perform a cartesian join on those two tables? Mark for Review