expdp 导出报ORA-01555: snapshot too old错误

ORA-31693: Table data object "APPLSYS"."FND_LOBS" failed to load/unload and is being skipped due to error:ORA-02354: error in exporting/importing dataORA-01555: snapshot too old: rollback segment number 154 with name "_SYSSMU154_1434655980$" too small

SQL> show parameter undo;NAME                                 TYPE        VALUE------------------------------------ ----------- ------------------------------undo_management                      string      AUTOundo_retention                       integer     900undo_tablespace                      string      UNDOTBS1SQL> select max(maxquerylen) from v$undostat;MAX(MAXQUERYLEN)----------------16331SQL> select retention from dba_lobs where owner='APPLSYS' and table_name='FND_LOBS';RETENTION----------900

1. Modify the current UNDO_RETENTION for the database:SQL>ALTER SYSTEM SET UNDO_RETENTION = 16500 scope=both sid='*';2. Modify the LOB retention to become greater than the undersized retention parameter following the steps from Note:563470.1SQL> alter table APPLSYS.FND_LOBS modify lob(FILE_DATA) (pctversion 5);Table altered.SQL> alter table APPLSYS.FND_LOBS modify lob(FILE_DATA) (retention);Table altered.3.  Query the lob retention again to verify that the change has taken hold:SQL> select retention from dba_lobs where owner='APPLSYS' and table_name='FND_LOBS';RETENTION----------16500