Ora-39126 Worker Unexpected Fatal Error In Kupw-worker.prepare-data-imp 71 Jun 2026

: Using a newer export version to import into an older database version without setting the parameter correctly. Resource Issues

This error indicates that a Data Pump worker process failed during the data preparation phase of an import operation, often pointing to an internal error or a data consistency issue rather than a simple syntax error. 1. Understanding the Error Structure

💡 The ORA-39126 [71] error is almost always a metadata inconsistency. Cleaning up orphaned Data Pump tables and excluding statistics are the highest-probability fixes. : Using a newer export version to import

The ORA-39126 error, particularly the variant Worker unexpected fatal error in KUPW$WORKER.PREPARE_DATA_IMP [71] , is a disruptive but solvable issue in Oracle Data Pump. By systematically investigating logs, understanding known bugs, and applying the appropriate patches or workarounds, database administrators can overcome this error and ensure the successful completion of their data imports. For a permanent and robust solution, always aim to have your Oracle environment patched to the latest version levels recommended by Oracle Support.

If the ORA-39126 error points to a specific package body or function, like DBMS_METADATA in the error stack, recompiling the invalid objects can resolve the issue. Understanding the Error Structure 💡 The ORA-39126 [71]

Many ORA-39126 errors originate from known Oracle bugs that affect specific database versions. These bugs can be triggered by particular combinations of object features, such as table compression, partitioning, LOB storage, or the use of specific Data Pump parameters. Applying the relevant patch is often the definitive solution for these cases.

Start by examining the full error stack, isolate the failing table, disable direct path, and incrementally apply transformations. In stubborn cases, rebuilding the dump file or adjusting the target database’s feature set (like Spatial or XML DB) is necessary. isolate the failing table

: Migration from Oracle 12c to 19c. impdp fails with:

You will likely see an underlying ORA-XXXXX . Common examples:

Proactive steps can significantly reduce the likelihood of encountering ORA-39126 errors.