ORA-12805: parallel query server died unexpectedly


Sometimes you can get  ” ORA-12805: parallel query server died unexpectedly ” error.


ORA-12805 parallel query server died unexpectedly

Details of error are as follows.

ORA-12805: parallel query server died unexpectedly

Cause: A parallel query server died unexpectedly, PMON cleaning up the process.

Action: Check your system for anomalies and reissue the statement. 
If this error persists, contact Oracle Support Services. See trace file for more details.


If you got this error with ORA-07445 [qertqistart] or ORA-600 [15803] in Oracle, this was related with bug 25694206 and it is corrected in version


To solve this error, Upgrade database from to 12.2 or run the following command for workaround.

SQL> alter system set "_px_wif_extend_distribution_keys"=false scope=both sid='*';

System altered.



If this error is not get with ORA-600 then you can solve it to run the following command.


Session altered.

Or you should Increase the  sort_area_size as follows.

SQL> show parameter sort_area

------------------------------------ ----------- ------------------------------
sort_area_retained_size integer 0
sort_area_size integer 65536

alter session set sort_area_size = 640000 scope=both sid='*';




Do you want to learn Oracle Database for Beginners, then read the following articles.

Oracle Tutorial | Oracle Database Tutorials for Beginners ( Junior Oracle DBA )

About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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