将undo_retntion改回之前的值再验证一下试试。

谢谢！

ORA-01554 Reason: No Undo Segment Found With Available Slot due to _rollback_segment_count=0 (Doc ID 2452558.1)

In this Document
Symptoms
Changes
Cause
Solution
References

APPLIES TO:
Oracle Database - Enterprise Edition - Version 11.2.0.4 and later
Information in this document applies to any platform.

SYMPTOMS
Below error message reported in the alert log file.

ORA-01554 reason: no undo segment found with available slot

CHANGES

CAUSE
Due to _rollback_segment_count=0 caused this issue

SOLUTION
Set using below command minimum “_rollback_segment_count”=100 and monitor the ORA-1554 error in alert log file.

SQL> alter system set “_rollback_segment_count”=100;

REFERENCES
NOTE:1579035.1 - Script - Check Current Undo Configuration and Advise Recommended Setup
Script - Check Current Undo Configuration and Advise Recommended Setup (Doc ID 1579035.1)