Platform		: Linuxx86_64 (OEL 7)
Server Name		: RAC1.RAJASEKHAR.COM, IP: 192.168.2.101
DB Version		: Oracle 19.3.0.0.0, File system: Normal
NON-CDB Name	        : DELL
Oracle Home Path        : /u01/app/oracle/product/19.0.0/dbhome_1

[oracle@rac1 ~]$ export ORACLE_HOME=/u01/app/oracle/product/19.0.0/dbhome_1
[oracle@rac1 ~]$ export PATH=$ORACLE_HOME/bin:$PATH
[oracle@rac1 ~]$ which dbca
/u01/app/oracle/product/19.0.0/dbhome_1/bin/dbca  <---
[oracle@rac1 ~]$ dbca 

[oracle@rac1 ~]$ cat /etc/oratab | grep -i dell
dell:/u01/app/oracle/product/19.0.0/dbhome_1:N  <-----
[oracle@rac1 ~]$

[oracle@rac1 ~]$ ps -ef | grep pmon
oracle   24068     1  0 18:57 ?        00:00:00 ora_pmon_dell
oracle   25204  2552  0 19:01 pts/0    00:00:00 grep --color=auto pmon
[oracle@rac1 ~]$

[oracle@rac1 ~]$ . oraenv
ORACLE_SID = [DELL] ? dell
The Oracle base remains unchanged with value /u01/app/oracle
[oracle@rac1 ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Sun Jan 26 19:02:20 2020
Version 19.3.0.0.0

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


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL> select name,open_mode,cdb from v$database;

NAME      OPEN_MODE            CDB
--------- -------------------- ---
DELL      READ WRITE           NO  <-----

SQL> show con_name

CON_NAME
------------------------------
dell
SQL> select name from v$datafile
UNION
select name from v$tempfile; 

NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/DELL/sysaux01.dbf
/u01/app/oracle/oradata/DELL/system01.dbf
/u01/app/oracle/oradata/DELL/temp01.dbf
/u01/app/oracle/oradata/DELL/undotbs01.dbf
/u01/app/oracle/oradata/DELL/users01.dbf

SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
[oracle@rac1 ~]$ ps -ef | grep tns
root        15     2  0 12:28 ?        00:00:00 [netns]
oracle   19876     1  0 18:41 ?        00:00:00 /u01/app/oracle/product/19.0.0/dbhome_1/bin/tnslsnr LISTENER_DELL -inherit
oracle   25594  2552  0 19:03 pts/0    00:00:00 grep --color=auto tns
[oracle@rac1 ~]$

[oracle@rac1 admin]$ cat listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/product/19.0.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.

LISTENER_DELL =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac1.rajasekhar.com)(PORT = 1522))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
    )
  )

[oracle@rac1 admin]$

[oracle@rac1 ~]$ lsnrctl status LISTENER_DELL | grep -i "dell"
Alias                     LISTENER_DELL
Listener Log File         /u01/app/oracle/diag/tnslsnr/rac1/listener_dell/alert/log.xml
Service "dell.rajasekhar.com" has 1 instance(s).
  Instance "dell", status READY, has 1 handler(s) for this service...
Service "dellXDB.rajasekhar.com" has 1 instance(s).
  Instance "dell", status READY, has 1 handler(s) for this service...
[oracle@rac1 ~]$



[oracle@rac1 admin]$ cat tnsnames.ora
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/19.0.0/dbhome_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

LISTENER_DELL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = rac1.rajasekhar.com)(PORT = 1522))


DELL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = rac1.rajasekhar.com)(PORT = 1522))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = dell.rajasekhar.com)
    )
  )

[oracle@rac1 admin]$


[oracle@rac1 ~]$ tnsping dell

TNS Ping Utility for Linux: Version 19.0.0.0.0 - Production on 26-JAN-2020 19:04:49

Copyright (c) 1997, 2019, Oracle.  All rights reserved.

Used parameter files:
/u01/app/oracle/product/19.0.0/dbhome_1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = rac1.rajasekhar.com)(PORT = 1522)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = dell.rajasekhar.com)))
OK (10 msec)
[oracle@rac1 ~]$

[oracle@rac1 ~]$ sqlplus sys@dell as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Sun Jan 26 19:06:48 2020
Version 19.3.0.0.0

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

Enter password:

Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL> select to_char(sysdate,'DD-MON-YYYY HH24:MI:SS') "SYSDATE" FROM DUAL;

SYSDATE
-----------------------------
26-JAN-2020 19:07:06

SQL>