If you are still experiencing this error, ensure your database is updated to the latest patch set to resolve known DBMS_METADATA bugs.
To resolve the ORA-39126 error, follow these troubleshooting steps:
The full error message usually appears as:
The database objects that track Data Pump progress ( SYS views and internal packages like DBMS_METADATA or XDB ) may be invalid, missing, or corrupted. If you are still experiencing this error, ensure
Data Pump uses a master table ( SYS_IMPORT_TABLE_xx ) to keep track of operations. If this table is corrupted, restart the job using impdp ... TABLE_EXISTS_ACTION=TRUNCATE .
Because ORA-39126 is an unhandled internal exception wrapper, the true culprit is often found in subsequent lines of the error log or the database alert log. In the context of PREPARE_DATA_IMP [71] , the error usually boils down to a handful of architectural issues: 1. Data Pump Metadata Component Corruption
impdp ... TABLE_EXISTS_ACTION=TRUNCATE
If internal corruption is suspected, reload the Data Pump metadata objects. For 12c and higher: @?/rdbms/admin/dpload.sql (for CDB/PDB environments, ensure PDBs are open). For older versions (10g/11g): @?/rdbms/admin/catdp.sql @?/rdbms/admin/catmetx.sql Check for Invalid Objects: Ensure all objects are valid. owner, object_name, object_type dba_objects Use code with caution. Copied to clipboard Recompile any invalid objects using the @?/rdbms/admin/utlrp.sql Verify Temporary Tablespace:
If the target database's Data Pump components or dependent XML/Metadata APIs ( SYS.DBMS_METADATA ) became corrupted during a database upgrade, power crash, or partial patch application, the worker process will fail when preparing the load configurations. 2. Missing or Misconfigured Temporary Tablespaces
Outdated statistics on internal dictionary tables or fixed objects can cause Data Pump to fail during its preparation queries. Invalid Objects: Dependent objects like SYS.KUPW$WORKER SYS.DBMS_METADATA might be invalid. Empty Temporary Tablespace: If this table is corrupted, restart the job using impdp
The most common cause. If the dump file was transferred incompletely (FTP in ASCII mode instead of binary), stored on a faulty filesystem, or created with a different Oracle version, the worker cannot parse the data stream.
Prevention is better than cure. Implement the following strategies to minimize the risk of encountering this error in Data Pump jobs: