OracleXE installation and permission problems - oracle

Question

Reference:
How to connect using PDB userid on Oracle 18c XE?
TNS Protocol adapter error
Product I am trying to install / configure: OracleXE 18c
Problem 1:
Attempting to log in as described in the Installation Guide returns the error shown below:
sqlplus / as sysdba
ORA-12560: TNS:protocol adapter error
Problem 2:
The following command fails immediately before asking for a password:
sqlplus system#localhost:1521/XEPDB1
ERROR:
ORA-01017: invalid username/password; logon denied
Enter user-name: system
Enter password:
ERROR:
ORA-12560: TNS:protocol adapter error
Problem 3:
I tried ALTER PLUGGABLE DATABASE ALL OPEN; as is mentioned in one of the the reference issues cited at the top of this post.
The command completes successfully. However trying run STARTUP as mentioned here
results in an error:
SQL> startup;
ORA-01031: insufficient privileges
ORA-01078: failure in processing system parameters
SQL>
Running whoami at the windows command prompt returns my user name which has admin priviliges and is the same one used to install OracleXE.
Additional Background:
I am able to log in as follows:
sqlplus system#localhost:1521
When I installed Oracle XE it created tnsnames.ora and listner.ora using mymachine.mydomain.com as host. The completion screen of the installer told
me to log in using localhost:1521 which does not work. After several hours of research I discovered that if I change mymachine.mydomin.com to localhost
in tnsnames.ora and listener.ora I could log in as system#localhost:1521. The above three problems remain however.
Running select value from v$parameter where name='service_names' as described in the ticket referenced above returns only one row: XE. Should it also
return a row for XEPDB1?
tnsnames.ora
XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)
XEPDB1 =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XEPDB1)
)
)
listner.ora
DEFAULT_SERVICE_LISTENER = XE
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\app\myname\product\18.0.0\dbhomeXE)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\app\myname\product\18.0.0\dbhomeXE\bin\oraclr18.dll")
)
(SID_DESC =
(SID_NAME=XE)
(ORACLE_HOME=C:\app\myname\product\18.0.0\dbhomeXE)
(GLOBAL_DBNAME=XE)
)
(SID_DESC =
(SID_NAME=XEPDB1)
(ORACLE_HOME=C:\app\myname\product\18.0.0\dbhomeXE)
(GLOBAL_DBNAME=XEPDB1)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
lsnrctl status
LSNRCTL for 64-bit Windows: Version 18.0.0.0.0 - Production on 23-APR-2021 15:55:00
Copyright (c) 1991, 2018, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 64-bit Windows: Version 18.0.0.0.0 - Production
Start Date 23-APR-2021 12:09:44
Uptime 0 days 3 hr. 45 min. 16 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File C:\OracleClient\listener.ora
Listener Log File C:\app\myname\product\18.0.0\diag\tnslsnr\mymachine\listener\alert\log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
Instance "XE", status UNKNOWN, has 1 handler(s) for this service...
Service "XEPDB1" has 1 instance(s).
Instance "XEPDB1", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
sqlnet.ora
# sqlnet.ora Network Configuration File: C:\OracleClient\sqlnet.ora
# Generated by Oracle configuration tools.
SQLNET.AUTHENTICATION_SERVICES= (NTS)
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

Answer 1

Problem 1:
To use OS authentication on Windows your user should be in ORA_DBA group and sqlnet.ora must contain
SQLNET.AUTHENTICATION_SERVICES= (NTS)
updated: I see NTS was configured already, so just check if you are in the ORA_DBA group
Problem 2:
EZCONNECT: try this syntax with //
sqlplus system#//localhost:1521/XEPDB1
Problem 3:
You need to check the alert.log. You can save init parameters and post your parameter here:
alter system create pfile='c:/temp/init.ora' from spfile;
and then just post this file and startup errors from alert.log

Answer 2

If you omit password when connecting through sqlplus you need escaping.
This was my experience when I used WindowsOS. I just tried Easy Connect on my MacOS where it works with or without escaping.
REM password in clear text.
C:\>sqlplus user/password#host:port/SERVICE_NAME
REM you will be prompted for password
C:\>sqlplus user#"\host:port/SERVICE_NAME\"
Best of luck!