Which statement is true?
A.
Stored functions can be called from the SELECT and WHERE clauses only.
B.
Stored functions do not permit calculations that involve database links in a distributed environment.
C.
Stored functions cannot manipulate new types of data, such as longitude and latitude.
D.
Stored functions can increase the efficiency of queries by performing functions in the query rather than in the application.
Explanation:
User-defined functions increase the efficiency of queries by applying the functions in the query
itself. This drastically improves the performance because the query is designed to use the function instead of using the query and functions separately from client-side tools when enforcing
application logic.
Incorrect Answers
A: Functions can be invoked as part of SELECT statements (in the column list, WHERE, GROUP BY, HAVING
and ORDER BY clauses), in the UPDATE statement (in the SET and WHERE clause), in the DELETE
statement (in the WHERE clause), and in the INSERT statement (in the VALUES clause).
B: Functions allow calculations on data across a database link. C: Functions can be used to manipulate these data types.