Why Can an Object Not Be Exported? Expdp of SYSTEM User's Table Returns ORA-39166 or ORA-31655
Last updated on MARCH 20, 2017
Applies to:Oracle Database - Standard Edition - Version 18.104.22.168 and later
Oracle Database - Enterprise Edition - Version 22.214.171.124 to 126.96.36.199 [Release 9.2]
Information in this document applies to any platform.
This document explains why certain objects cannot be exported, and how to find those objects.
There are certain system generated schemas that are not exportable using exp or expdp because they contain Oracle-managed data and metadata. SYS, MDSYS, and ORDSYS are some examples.
In addition, there are other tables owned by users such as SYS or APEX_040200 which are automatically skipped during export, nor can those be exported intentionally.
For example, certain tables owned by SYSTEM user like below cannot be exported:
% expdp system/manager directory=my_dir tables='REDO_DB'
Export: Release 188.8.131.52.0 - Production on Thu Mar 3 20:39:27 2016
Copyright (c) 1982, 2014, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 184.108.40.206.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
Starting "SYSTEM"."SYS_EXPORT_TABLE_01": system/******** directory=my_dir tables=REDO_DB
Estimate in progress using BLOCKS method...
Total estimation using BLOCKS method: 0 KB
Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
ORA-39166: Object SYSTEM.REDO_DB was not found or could not be exported or imported.
ORA-31655: no data or metadata objects selected for job
Job "SYSTEM"."SYS_EXPORT_TABLE_01" completed with 2 error(s) at Thu Mar 3 20:39:31 2016 elapsed 0 00:00:03
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