ORA-01555: snapshot too old


If you get ORA-01555: snapshot too old error when you execute any query, then you have a problem with undo management or undo tablespaces.

This error occurs when your undo_retention parameter is small or undo_tablespace size is insufficient. You need to increase undo_retention parameter like below steps in Oracle 19c. Or you should add datafile to the undo_tablespaces to increate tablespace size.

[oracle@MehmetSalih admin]$ sqlplus / as sysdba

SQL*Plus: Release - Production on Fri Mar 1 14:06:29 2019

Copyright (c) 1982, 2018, Oracle. All rights reserved.

Connected to:
Oracle Database 19c Enterprise Edition Release - Production

SQL> show parameter undo

------------------------------------ ----------- ------------------------------
temp_undo_enabled boolean FALSE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
SQL> alter system set undo_retention=90000 scope=both;

System altered.



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Mehmet Salih Deveci

I am Founder of 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 mehmetsalih.deveci@outlook.com.-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  mehmetsalih.deveci@outlook.com a mail atabilirsiniz.

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