oracle - ORA-01092 Oracle インスタンスが終了しました。切断された

Question

Oracle 11g データベースを起動しようとしていますが、ORA-01092 および ORA-00600 エラーで失敗しています:

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Administrator>sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Wed Sep 11 15:21:30 2019

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup upgrade
ORACLE instance started.

Total System Global Area  430075904 bytes
Fixed Size                  2176448 bytes
Variable Size             356518464 bytes
Database Buffers           67108864 bytes
Redo Buffers                4272128 bytes
Database mounted.
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00600: internal error code, arguments: [4194], [], [], [], [], [], [], [],
[], [], [], []
Process ID: 5044
Session ID: 1 Serial number: 5

SQL> conn
Enter user-name: delhipilot
Enter password:
ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Process ID: 0
Session ID: 0 Serial number: 0

SQL>

データベースを適切に起動するにはどうすればよいですか?