ORA-01034: ORACLE not available

• This error occurs when the Oracle instance is not running or is not properly configured. Check if the instance is starting up correctly and if all necessary services are running.

ORA-12541: TNS no listener

• This error indicates that the listener service, which is responsible for establishing connections to the Oracle database, is not running or is not configured correctly. Check the listener configuration and ensure it is running.

ORA-01102: cannot mount database in EXCLUSIVE mode

• This error occurs when trying to mount a database that is already mounted by another instance. Ensure that no other instances are trying to mount the same database in exclusive mode.

ORA-12560: TNS protocol adapter error

• This error typically occurs when the Oracle client is unable to establish a connection to the database due to misconfiguration or network issues. Check the TNSnames.ora file and ensure that the correct service name and host are specified.

ORA-00257: archiver error. Connect internal only, until freed

• This error indicates that the archiver process is unable to archive redo logs due to insufficient space or other issues. Check the available disk space, archive log destination settings, and ensure that the archiver process is running.

ORA-00313: open failed for members of log group

• This error occurs when Oracle is unable to open a redo log file for a specific log group. Check the file permissions, disk space, and ensure that the file is not corrupted.

ORA-00600: internal error code, arguments: [xxxx], [xxxx], [xxxx], [xxxx], [xxxx], [xxxx]

• This error indicates a critical internal error within the Oracle database. This error usually requires Oracle support to diagnose and fix, as it may be related to a bug or corruption in the database.

ORA-01089: immediate shutdown in progress - no operations are permitted

• This error occurs when trying to perform operations on the database while it is in the process of shutting down. Wait for the shutdown process to complete before attempting any operations.

ORA-04030: out of process memory when trying to allocate xxxxx bytes

• This error indicates that the Oracle database is running out of memory for a specific operation. Check the memory settings and consider increasing the memory allocation for the relevant components.

ORA-12154: TNS:could not resolve the connect identifier specified

• This error indicates that the Oracle client is unable to resolve the service name specified in the connection string. Check the TNSnames.ora file for the correct service name and ensure that the hostname and port are correct.