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René Nyffenegger on Oracle - Most wanted - Feedback
 

set feedback [SQL*Plus]

SQL> set feedback off
SQL> set feedback on
SQL> set feedback n
By default, sql*plus will give a short feedback when an sql statement was issued. For example, if a table was created, sql*plus will tell the user: Table created. Or, if a procedure has ended, sql*plus lets one know: PL/SQL procedure successfully completed
I find this behaviour a bit of a nuisance when I run a script with a lot of statements in it, so I usually turn this behaviour off with set feedback off

Set feedback n

Set feedback n instruct SQL*Plus to give a feedback when a select statement returns n or more rows. 
set feedback off

drop table feedback_test;

create table feedback_test (
  a number
);

insert into feedback_test values (1);
insert into feedback_test values (2);
insert into feedback_test values (3);
insert into feedback_test values (4);
insert into feedback_test values (5);
insert into feedback_test values (6);
insert into feedback_test values (7);
insert into feedback_test values (8);

commit;
Setting feedback to five: 
set feedback 5

select * from feedback_test;
The select statement returns 8 rows which is more than 5-1 
         A
----------
         1
         2
         3
         4
         5
         6
         7
         8

8 rows selected.
Setting feedback to ten. 
set feedback 10

select * from feedback_test;
Now, Oracle won't give feedback because only 8 rows are returned and feedback is set to 10. 
         A
----------
         1
         2
         3
         4
         5
         6
         7
         8

Storing settings across sessions

Settings (such as feedback) can be stored accross sessions with the glogin.sql and/or login.sql file.