数据库报 ORA-00020错误且sys用户无法正常登录

数据库内连接会话超过参数配置，导致报错ORA-00020:maximum number of processes (500) exceeded同时sys用户无法正常登录
[oracle@test ~]$ sqlplus / as sysdbaSQL*Plus: Release 11.2.0.4.0 Production on Fri Mar 4 13:05:22 2022
Copyright (c) 1982, 2009, Oracle. All rights reserved.

ERROR:
ORA-00020:maximum number of processes (500) exceeded

Enter user-name:




解决 ORA-00020 错误，加大processes的参数值即可，但是需要sys用户能够登录进行参数调整
通过加参数 “-prelim” 强制登陆数据库sqlplus -prelim / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Fri Mar 4 13:10:09 2022

Copyright (c) 1982, 2009, Oracle. All rights reserved.


SQL>

此时就可以正常关闭和开启数据库，进行参数调整