ORA-01555 snapshot too old error with UNDO tablespace configuration and retention fix for Oracle 19c

ORA-01555: Snapshot Too Old – Complete Fix Guide for Oracle 19c

Posted on December 10, 2025December 10, 2025 by sanjeeva

The Problem: Long-Running Query Fails with ORA-01555 You’re running a critical report or data export, and after 30 minutes it fails with: When this happens: The query was working fine yesterday. The data hasn’t changed much. But today it fails with ORA-01555. This guide shows you exactly how to fix it permanently. What is ORA-01555 Read more about ORA-01555: Snapshot Too Old – Complete Fix Guide for Oracle 19c[…]

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