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ORA-01555 Using Automatic Undo Management - Causes and Solutions (Doc ID 269814.1)

Last updated on JULY 05, 2023

Applies to:

Oracle Database - Enterprise Edition - Version and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.


This article discusses the circumstances under which a query can return the ORA-01555 "snapshot too old (rollback segment too small)" error when using the Automatic Undo Management (hereafter called AUM) feature and also possible solutions to this error.


This document is intended for Oracle DBAs experiencing the ORA-01555 error.


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