In this article, I’d like to shed some light on the most common problem while working with Oracle: ora 27101 shared memory realm does not exist. When the local shared memory realm is inaccessible, the ORA-27101: shared memory realm does not exist. An error will occur in Oracle documentation, which describes several forms of Oracle failures in depth. For whatever reason, your Oracle database instance is shutting down. Rebooting the server merely restarts the Oracle Service SID service, which restarts the Oracle instance. There might be several reasons why your Oracle instance is ending unexpectedly. The only way to be certain is to go through your Alert log for hints. There should be an error message describing the reason for the instance’s termination, pointing to the underlying cause.
Launching the Database from the Desktop
The database from the Windows desktop and the Linux windowing managers KDE and Gnome. If your Linux machine does not have a windowing manager or that manager other than KDE or Gnome, you must launch the database using the SQL Command-Line.
To launch the database from the desktop, follow these steps:
- On Windows, log in as the user who installed Oracle Database XE or as a Windows administrator—that is, as a member of the Administrator group.
- On Linux, log in as the user who installed Oracle Database XE or a member of the dba user group to the Oracle Database XE host machine.
- Typically, this is the user oracle.
- On Gnome Linux, navigate to the Applications menu, pick Oracle Database 11g Express Edition, and then click Start Database.
- On Linux with KDE, open the K Menu icon, navigate to Oracle Database 11g Express Edition, and then select Start Database.
It would help if you connected to the databases using the database start function. These are the two possible solutions for ORA-27101: the shared memory realm does not exist with examples. I hope this gives you some ideas for fixing the ORA-27101: Error: shared memory realm does not exist.