Chapter 23. DBMS_OUTPUT Built-in Package
This chapter tests your understanding of DBMS_OUTPUT, the built-in package that allows you to display messages to your session’s standard output device.
Before developers had DBMS_OUTPUT, how did they obtain information about the activity that had taken place inside their code?
DBMS_OUTPUT has a buffer or memory area defined inside the package that holds the data you want displayed until the time comes to “flush” it to the screen. What is the maximum size of the buffer for any single PL/SQL block execution? What are the different types of information you can put in the buffer?
Write a “Hello World” procedure that puts into the DBMS_OUTPUT buffer (and eventually displays on the screen) the string “hello world” followed by a newline character.
How do you enable output from the DBMS_OUTPUT package?
How do you enable DBMS_OUTPUT in your SQL*Plus session?
How can you flush the DBMS_OUTPUT buffer and turn off output from this package?
What is the default size of the DBMS_OUTPUT buffer in SQL*Plus?
How do you minimize the chance of hitting the buffer overflow error when working with DBMS_OUTPUT in SQL*Plus?
Write a procedure to display the current date and time on two different lines.
Write a procedure to display the last_name and salary of each person in the employee table.
Explain the output displayed in the following session in SQL*Plus:
SQL> SET SERVEROUTPUT ON SQL> EXEC DBMS_OUTPUT.PUT_LINE ...