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Ora-01555 During Direct Path Read Of Securefile Lob (Doc ID 1339051.1)

Last updated on JANUARY 30, 2022

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.


Performing a Data Pump export of a table with SecureFile LOBs with concurrent updates of this table.

Generates the error:
Errors in file /<$ORACLE_BASE>/diag/rdbms/prod/PROD/trace/INSTANCENAME_dw00_PID.trc
ORA-01555: snapshot too old: rollback segment number with name "" too small

The table is fairly large (200 million rows) and the error occurs roughly after 20 million
rows have been exported. It took 24 - 36 hours to produce the error with the table
of this size and the UNDO_RETENTION set to 7 days.


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