Databases Reference
In-Depth Information
In the following screenshot, we can see the execution plan and statistics for this query:
Using a
JOIN
, we have avoided the two
SORT
operations required in the previous query (but
the Full Table Scans are always there), obtaining better performance for the same query.
In step 6, we execute a query using the
MINUS
operator to retrieve all the last names of the
CUSTOMERS
except the last names that are also in the
MY_EMPLOYEES
table.
