How to connect the oracle Database in linux enviromnets?

 The contents are of my own testing and deployments. Not guaranteed that these might work in your environment. Please test before usage.

1) log in to the server 

2)Confirm the DB name and services are running or not?

3)set the environment variable?

4)connect sqlplus 

1) log in to the server 

2)Confirm the DB name and services are running or not?

[oracle@ltitest ~]$ ps -ef |grep pmon

oracle    3511  3166  0 12:30 pts/0    00:00:00 grep --color=auto pmon

[oracle@ltitest ~]$

Note: services aren't running

3)set the environment variable?

[oracle@ltitest ~]$ . oraenv

ORACLE_SID = [oracle] ? Here type your database name

The Oracle base has been set to /u01/app/oracle

[oracle@ltitest ~]$

4)connect sqlplus 

[oracle@ltitest ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Wed Feb 22 12:32:26 2023

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to an idle instance.

SQL>

Note: in that case, DB is down so we need to start my database.

SQL> startup;

ORACLE instance started.

Total System Global Area  713031680 bytes

Fixed Size                  2928488 bytes

Variable Size             587202712 bytes

Database Buffers          117440512 bytes

Redo Buffers                5459968 bytes

Database mounted.

Database opened.

SQL> select name,open_mode from v$database;

NAME      OPEN_MODE

--------- --------------------

DBNAME   READ WRITE

SQL>

Thanks for your time!!

Thanks

Rameshbabu