ORA-01555: snapshot too old with manual undo - Causes and Solutions

(Doc ID 1005107.6)

Last updated on AUGUST 25, 2017

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 8.1.7 to 11.1]
Information in this document applies to any platform.
***Checked for relevance on 21-Jul-2017***


A transaction fails with an ORA-01555 error.

ORA-01555: snapshot too old (rollback segment too small)
    Cause: rollback records needed by a reader for consistent read are overwritten by other writers

The information here is primarily intended for the old type of rollback segments with manual UNDO.
For additional information and specific information for ORA-1555 with automatic UNDO, please refer to:
Note 1307334.1 - Master Note for ORA-1555 Errors
Note 467872.1 - TROUBLESHOOTING GUIDE (TSG) - ORA-1555
Note 269814.1 - ORA-01555 Using Automatic Undo Management - Causes and Solutions



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