In this post, you’ll learn more about the Oracle ErrorORA-12804: parallel query server appears to have died with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
ORA-12804: parallel query server appears to have died
Reason for the Error ORA-12804: parallel query server appears to have died
Cannot find process information for a parallel query server thread.
How to fix the Error ORA-12804: parallel query server appears to have died ?
You can fix this error in Oracle by following the below steps
Check your system for anomalies and reissue the statement. If this error persists, contact Oracle Support Services.