Search code examples
oracle-databaseoracle-xe

Oracle 11g XE - Can't login and database is down

Just installed Oracle 11g XE (Windows), but can't connect in SQL Developer or run any command in CLI. When try to connect in CLI using SYS or SYSTEM with password defined during the install, get the following error:

ORA-12638: credential retrieval failed

When I tray to connect via SQL Developer (tried via SID and Service Name, hostname=localhost, port=1521, SID=xe), get this error:

Status : Listener refused the connection with the following error: ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

Already tried change SQLNET.AUTHENTICATION_SERVICES = (NTS) to (NONE) in sqlnet.ora file. When I do this, get the following error when try to connect with the SYS or SYSTEM user and password:

ORA-01034: ORACLE not available

ORA-27101: shared memory realm does not exist

Already tried every solution in Google results, like reinstall, stop and start services... Mostly ask for first connect in CLI to make some changes, but even this I can't accomplish.

Any suggestions on how connect to the database?

Solution

  • Found the solution:

    I was installing in my company Windows user domain.

    1. First uninstall any instance of Oracle XE 11g.
    2. Switch to a local administrator Windows user and install Oracle XE 11g.
    3. Sign off and back to company Windows user.
    4. Edit the file C:\oraclexe\app\oracle\product\11.2.0\server\network\ADMIN\sqlnet.ora (or equivalent to your installation path). Change SQLNET.AUTHENTICATION_SERVICES = (TNS) to SQLNET.AUTHENTICATION_SERVICES = (NONE). This change will allow you connect to database from you company Windows user.

    As seen here: Error ORA-12638 in Oracle Database 11g