When you use Sqlplus to execute SQL, a prompt like a SELECT statement usually returns a result with a "line returned XX", but recently opened a library and found no such hint. by @ Qiao Xiaoyang Master Pointing, There is a feedback parameter setting, now summarized as follows.
feedback can be shortened to a feed, it has three values: On/off/n,on to open the SQL feedback (DDL and DML, plsql slightly different ), off to turn off feedback, N means you can set an integer, Feedback is only available when the result of SQL returns is greater than or equal to N.
Experiment:
1. Query results for off and on feeds :
2. Check the default settings of the feed, when returning 6 lines will have feedback, by executing sqL can explain this point :
3. Set feed n, specify return n rows on feedback :
Summary :
Oracle in any small link , there is a wealth of knowledge points , different results have different reasons, which reflects the charm of Oracle as the eldest, can only sigh oneself too small, need to learn too much, mutual encouragement!
Feedback settings in the Sqlplus