Oracle DBMS_OUTPUT屏幕打印信息

可参考官方的说明，就是给sqlplus使用进行调试的，如下：

The package is typically used for debugging, or for displaying messages and reports to SQLDBA or SQLPlus (such as are produced by applying the SQL command DESCRIBE to procedures).

一般情况下，此设置默认是关闭的，需要通过命令进行打开：

>sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on 星期三 1月 5 23:48:46 2022
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.


连接到:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL> set serveroutput on;

但上述方式只是针对当前会话有效，如果退出后再登录就会失效，需要重新设置，如果需要永久打开，可使用下面的方法，在$ORACLE_HOME/sqlplus/admin/目录下的glogin.sql文件中增加set serveroutput on这句代码，如下：

--
-- Copyright (c) 1988, 2005, Oracle.  All Rights Reserved.
--
-- NAME
--   glogin.sql
--
-- DESCRIPTION
--   SQL*Plus global login "site profile" file
--
--   Add any SQL*Plus commands here that are to be executed when a
--   user starts SQL*Plus, or uses the SQL*Plus CONNECT command.
--
-- USAGE
--   This script is automatically run
--
set serveroutput on