1z0-071 Exam Dumps : Oracle Database 12c SQL

C: True. To display the number of products whose PROD_LIST_PRICE is more than the average PROD_LIST_PRICE, you would need to use a subquery to first calculate the average PROD_LIST_PRICE and then use that result to compare each product’s list price to the average.

E: True. Displaying products whose PROD_MIN_PRICE is more than the average PROD_LIST_PRICE of all products and whose status is orderable would require a subquery. The subquery would be used to determine the average PROD_LIST_PRICE, and then this average would be used in the outer query to filter the products accordingly.

Subqueries are necessary when the computation of a value relies on an aggregate or a result that must be obtained separately from the main query, and cannot be derived in a single level of query execution.

References:Oracle's SQL documentation provides guidelines for using subqueries in scenarios where an inner query's result is needed to complete the processing of an outer query.

In Oracle, *_TABLES views provide information about tables.

B. USER_TABLES displays all tables owned by the current user, making this statement true. No additional privileges are required to see your own tables.

D. ALL_TABLES displays all tables that the current user has access to, either through direct ownership or through privileges, making this statement true.

A, C, E, and F are incorrect. Specifically:

A and E are incorrect because you do not need ANY TABLE system privileges to view tables in DBA_TABLES or ALL_TABLES; you need the SELECT_CATALOG_ROLE or equivalent privileges.

C is incorrect because as a user, you do not need additional privileges to see your own tables in USER_TABLES.

F is incorrect because not all users can query DBA_TABLES; this requires specific privileges or roles.

References:

Oracle Database Reference, 12c Release 1 (12.1): "Static Data Dictionary Views"

Based on the given PRODUCTS table and the SQL queries provided:

Query 1: Excludes rows where prod_list is 10 or 20 and category_id is 1.

Query 2: Includes rows where prod_list is neither 10 nor 20 and category_id is 1.

Query 3: Excludes rows where prod_list is both 10 and 20 (which is not possible for a single value) and category_id is 1.

The correct answer is A, queries 1 and 3 will produce the same result. Both queries exclude rows where prod_list is 10 or 20 and include only rows from category_id 1. The NOT IN operator excludes the values within the list, and <> ALL operator ensures that prod_list is not equal to any of the values in the list, which effectively excludes the same set of rows.

Query 2, using the <> ANY operator, is incorrect because this operator will return true if prod_list is different from any of the values in the list, which is not the logic represented by the other two queries.