The tnsnames. ora file is changed and the instance cannot be started.

Recently, after the database service of one machine is started, the client cannot connect. Restart the instance:

SQL> startup
ORA-00119: Invalid specification for system parameter local_listener
ORA-00132: syntax error or unresolved network name 'listener _ ora92'

Close an instance:

SQL> shutdown immediate
A ORA-01034: Oracle not available
ORA-27101: Shared Memory realm does not exist

According to the following analysis, 'listener _ ora92' is the problem. In the tnsnames. ora file, check the file and find that the configuration information is missing. Add it again:

Listener_ora92 =
(Address = (Protocol = IPC) (Key = extproc0 ))

Restart the instance:

SQL> startup
The Oracle routine has been started.

Total system global area 47258064 bytes
Fixed size 453072 bytes
Variable Size 33554432 bytes
Database buffers 12582912 bytes
Redo buffers 667648 bytes
The database has been loaded.
The database has been opened.

OK!