在完成 GaussDB 的安装之后，应该及时修改缺省的用户口令，避免发生安全问题。

缺省的系统存在两个帐号，SYS 是系统的 SYSDBA 用户，PUBLIC 是一个特殊都公用用户对象。

SQL> select username from dba_users;
USERNAME
------------------------------------------------------
SYS
PUBLIC

SYS 用户的缺省口令是： Changeme_123

[root@enmodb1 ~]# su - eygle
Last login: Wed Dec 4 22:41:05 CST 2019 on pts/1
[eygle@enmodb1 ~]$ zsql SYS/Changeme_123@127.0.0.1:1888

Warning: SSL connection to server without CA certificate is insecure. Continue anyway? (y/n):y
connected.

SQL> select * from v$version;

VERSION

GaussDB_100_1.0.0.B019 Release 0b7bb43
ZENGINE
0b7bb43

3 rows fetched.

SQL> ALTER USER SYS IDENTIFIED BY ENmotech_100 REPLACE Changeme_123;

Succeed.

SQL> connect SYS/ENmotech_100@127.0.0.1:1888

Warning: SSL connection to server without CA certificate is insecure. Continue anyway? (y/n):y
connected.

SQL>

这样就完成了数据库创建之后的第一个安全工作。