Ora-39126 Worker Unexpected Fatal Error In Kupw-worker.prepare-data-imp 71 Extra Quality Link

ORA-39126: Worker unexpected fatal error in KUPW$WORKER.PREPARE_DATA_IMP [71]

is a generic "unhandled exception" within the Data Pump worker process, typically occurring during the initial setup of an import job. While the code

identifies the specific internal routine failing, this error often stems from environment mismatches or corrupted Data Pump metadata. Potential Causes Permissions & Sessions : Running Data Pump as

can trigger unexpected behavior or performance issues; it is recommended to use a user with the DATAPUMP_IMP_FULL_DATABASE role instead. Metadata Corruption : The Data Pump packages or required views (like SYS.DBMS_METADATA ) might be invalid or missing. Version Mismatch

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

: An empty or improperly configured default temporary tablespace can cause the worker process to fail during initial work item dispatch. Recommended Solutions

Common Causes and Scenarios

The PREPARE-DATA-IMP phase is critical because Data Pump must reconcile the source dump file’s metadata and data with the target database’s environment. Here are the most frequent triggers for this error:

Troubleshooting Steps

7. Insufficient Memory or PGA

The worker process requires enough Program Global Area (PGA) to prepare data, especially for large rows, LOBs, or row batches. If PGA_AGGREGATE_TARGET is too low, the worker may abort.

Understanding the Error Anatomy

6. Triggers or Unusable Constraints on Target

Even though Data Pump attempts to disable triggers and constraints during import, user-defined triggers or ENABLED VALIDATE constraints can interfere during the data preparation phase.

Conclusion

The ORA-39126 worker unexpected fatal error in KUPW-WORKER.PREPARE-DATA-IMP [71] is a complex, often frustrating error, but it is rarely insurmountable. By understanding that it signals a failure during the data preparation phase—often tied to LOBs, XML, spatial data, or conversion logic—you can systematically narrow down the root cause.

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.

Data Pump remains one of the most powerful tools in the Oracle DBA’s arsenal. With patience and the right diagnostic approach, even a "fatal error" becomes a solvable puzzle.

Have you encountered ORA-39126 with a different sub-code? Share your experience and solution in the comments below.

The ORA-39126 error during Data Pump import generally indicates a metadata corruption issue or a conflict involving statistics, often manifesting as an ORA-01403 "no data found" error. Common solutions involve excluding statistics (EXCLUDE=STATISTICS) during the import or revalidating the Data Pump components using dpload.sql.For further discussion on this error, see the Oracle Support Community. 

ORA-39126: Worker unexpected fatal error in KUPW$WORKER.PREPARE_DATA_IMP [71] — oracle-mosc

The Oracle error ORA-39126: Worker unexpected fatal error in KUPW$WORKER.PREPARE_DATA_IMP [71] is a generic "catch-all" internal error during a Data Pump import (impdp). It typically indicates that a worker process encountered an unhandled exception while preparing data for insertion. Primary Causes

Stale or Corrupt Dictionary Statistics: Inconsistent metadata in the database dictionary often causes the internal KUPW$WORKER package to fail.

Metadata Corruption: Corruption within the Data Pump utility or the DBMS_METADATA package can prevent the worker from correctly interpreting the dump file.

PDB Metadata Mismatch: If you are using Oracle 12c or higher, this error often occurs in Pluggable Databases (PDBs) where the Data Pump catalog is invalid or incomplete, frequently after a remote clone.

Empty Temporary Tablespace: While less common for code [71], an empty or incorrectly configured default temporary tablespace can trigger ORA-39126. Recommended Resolutions 1. Rebuild Data Pump Catalog

For most modern Oracle versions (12c+), the most effective fix is to rebuild the Data Pump utility packages to clear internal corruption. ORA-39126: Worker unexpected fatal error in KUPW$WORKER

Navigate to the admin directory: cd $ORACLE_HOME/rdbms/admin Execute as SYSDBA: SQL> @dpload.sql Use code with caution. Copied to clipboard

Note: In a Multitenant environment, ensure all PDBs are open and run this from the CDB. 2. Refresh Dictionary Statistics

Corrupt statistics can cause the worker to miscalculate data preparation. Run the following as SYSDBA:

exec dbms_stats.gather_dictionary_stats; exec dbms_stats.gather_fixed_objects_stats; Use code with caution. Copied to clipboard 3. Targeted Exclusion

If the error persists and is linked to specific objects, you can bypass the failure by excluding statistics or problematic schemas. Add EXCLUDE=STATISTICS to your impdp command.

If migrating between versions (e.g., 11g to 12c), avoid importing system schemas like SYSMAN or WMSYS. 4. Validate Environment Configuration

Temporary Tablespace: Ensure the default temporary tablespace is correctly assigned and has active tempfiles.

Check Invalid Objects: Run a script like utlrp.sql to recompile any invalid system packages, particularly those owned by SYS or XDB.

For more specific guidance, you can check the Oracle Community Discussion or consult Oracle Support Doc ID 1508068.1 on My Oracle Support.

ORA-39126: Worker unexpected fatal error in KUPW$WORKER.PREPARE_DATA_IMP [71]

is a generic internal error in Oracle Data Pump that typically indicates an unhandled exception within a worker process. The specific code

often points to an issue during the initialization phase where the worker is preparing for data import. Oracle Communities Potential Causes Corrupted Data Pump Metadata

: The internal packages or views used by Data Pump may be invalid or corrupted. Missing or Incorrect Tablespaces

: If the default temporary tablespace is missing or empty, Data Pump cannot manage the metadata for the import job. Schema Conflicts : Attempting to import system schemas (like ) along with application data can trigger this fatal error. Privilege Issues : Sometimes granting IMP_FULL_DATABASE

to a non-system user can cause unexpected behavior in certain environments. Bug-related issues

: Specific versions of Oracle have known bugs (e.g., bug 28307854) that cause ORA-39126 when importing package bodies or certain metadata. Oracle Forums Common Solutions and Workarounds To resolve this error, try the following steps in order:

ORA-39126 Worker Unexpected Fatal Error in KUPW-Worker.Prepare-Data-Imp 71: Causes, Solutions, and Troubleshooting Steps

The ORA-39126 error is a critical issue that can occur during data import operations using Oracle Data Pump, a utility that enables you to export and import data and metadata from one database to another. This error is specifically related to the KUPW-Worker.Prepare-Data-Imp 71 process, which is a worker process responsible for preparing data for import.

Understanding the ORA-39126 Error

The ORA-39126 error message typically appears as follows: Common Causes and Scenarios The PREPARE-DATA-IMP phase is

ORA-39126: Worker unexpected fatal error in KUPW-Worker.Prepare-Data-Imp 71

This error indicates that a worker process encountered an unexpected fatal error while preparing data for import. The error can occur due to various reasons, including:

1. Insufficient System Resources: The system may not have sufficient resources, such as memory or CPU, to handle the import operation.
2. Data Corruptions: Data corruptions or inconsistencies in the export file can cause the worker process to fail.
3. Database Configuration Issues: Incorrect database configuration, such as inadequate temporary space or incorrect character set settings, can lead to the ORA-39126 error.
4. Import Parameter Settings: Incorrect import parameter settings, such as insufficient memory allocation or incorrect data type mappings, can cause the error.

Causes of the ORA-39126 Error

To troubleshoot the ORA-39126 error, it's essential to understand the underlying causes. Some common causes include:

1. Inadequate Temporary Space: Insufficient temporary space can cause the worker process to fail while preparing data for import.
2. Data Type Mismatches: Data type mismatches between the source and target databases can lead to errors during the import process.
3. Character Set Issues: Character set mismatches or incorrect character set settings can cause data corruptions or inconsistencies.
4. LOB or BFILE Data Issues: Issues with LOB (Large OBject) or BFILE (Binary File) data, such as incorrect storage or invalid data, can cause the worker process to fail.

Solutions and Troubleshooting Steps

To resolve the ORA-39126 error, follow these troubleshooting steps:

1. Check System Resources: Ensure that the system has sufficient resources, such as memory and CPU, to handle the import operation.
2. Verify Export File Integrity: Check the export file for data corruptions or inconsistencies using tools like impdp with the VERIFY option.
3. Adjust Import Parameters: Adjust import parameter settings, such as increasing memory allocation or modifying data type mappings, to ensure compatibility with the target database.
4. Increase Temporary Space: Ensure that the target database has sufficient temporary space to handle the import operation.
5. Check Character Set Settings: Verify that character set settings are correct and consistent between the source and target databases.
6. Use the SKIP_UNUSABLE_INDEXES Parameter: Set the SKIP_UNUSABLE_INDEXES parameter to Y to skip indexes that are not usable during the import process.
7. Use the SQLFILE Option: Use the SQLFILE option to generate a SQL file that can be used to recreate the import operation.

Best Practices to Avoid the ORA-39126 Error

To minimize the risk of encountering the ORA-39126 error, follow these best practices:

1. Test Export and Import Operations: Test export and import operations in a non-production environment to ensure compatibility and identify potential issues.
2. Monitor System Resources: Monitor system resources during import operations to ensure sufficient resources are available.
3. Use Compatible Character Sets: Use compatible character sets between the source and target databases.
4. Verify Data Integrity: Verify data integrity before and after import operations using tools like DBVERIFY or impdp with the VERIFY option.
5. Regularly Maintain Database Statistics: Regularly maintain database statistics to ensure accurate data distribution and prevent data skew.

Conclusion

The ORA-39126 error can be a critical issue during data import operations using Oracle Data Pump. Understanding the causes, solutions, and troubleshooting steps can help database administrators and developers resolve the error efficiently. By following best practices and monitoring system resources, data integrity, and character set settings, you can minimize the risk of encountering the ORA-39126 error and ensure successful data import operations.

A very specific Oracle error!

ORA-39126 is a Data Pump error that occurs when there is an issue with the worker process. Here's a breakdown of the error:

ORA-39126: Worker unexpected fatal error in KUPW_WORKER.PREPARE_DATA_IMP

This error typically indicates that a worker process, which is responsible for executing a specific task during the import operation, encountered an unexpected fatal error while preparing data for import.

Possible causes:

1. Data corruption: Data corruption during the export or import process can cause this error.
2. Insufficient resources: Inadequate resources, such as memory or CPU, can lead to worker process failures.
3. Data Pump version mismatch: A mismatch between the Data Pump versions used for export and import can cause compatibility issues.
4. Database character set issues: Character set mismatches or invalid characters in the data can cause errors during import.
5. Internal errors: Rarely, internal errors in the Data Pump code can cause this error.

Additional information:

The error is occurring in the KUPW_WORKER.PREPARE_DATA_IMP procedure, which is part of the Data Pump worker process. The error code is 71, which is an internal Oracle error code.

Troubleshooting steps:

1. Check the import log: Review the import log file for any previous errors or warnings that may have contributed to this error.
2. Verify data integrity: Check the data for corruption or inconsistencies.
3. Increase resources: Ensure that the system has sufficient resources (e.g., memory, CPU) to perform the import.
4. Check Data Pump versions: Verify that the Data Pump versions used for export and import are compatible.
5. Try a different import method: If possible, try using a different import method, such as a conventional import or a transportable tablespace import.

Oracle Support or further assistance:

If you are unable to resolve the issue using the above steps, you may want to engage Oracle Support or a certified Oracle professional for further assistance. They can help you: Understanding the Error Anatomy 6

• Analyze the import log and error files
• Check for any known issues or patches related to this error
• Perform additional troubleshooting steps
• Provide guidance on recovering the import process, if possible.

Troubleshooting ORA-39126: Worker Unexpected Fatal Error in KUPW$WORKER.PREPARE_DATA_IMP [71]

If you are seeing the ORA-39126 error during an Oracle Data Pump Import (IMPDP), specifically referencing KUPW$WORKER.PREPARE_DATA_IMP [71], you have likely hit a snag in the metadata preparation phase. This error is a "catch-all" for unexpected internal worker failures, and the suffix [71] usually points to a specific issue with how the worker process is handling table data or partitioned objects. What Causes ORA-39126 (Internal Error 71)?

The error occurs when the Data Pump worker process encounters a condition it doesn't know how to handle. In the context of PREPARE_DATA_IMP [71], the most common culprits are:

Metadata Inconsistency: The source database has orphaned entries in the data dictionary or "ghost" partitions that the export file is trying to recreate.

Invalid Objects: The schema being imported contains invalid spatial indexes, functional indexes, or complex constraints that fail during the "prepare" phase.

Statistics Mismatch: Issues with importing table statistics, especially on partitioned tables, can trigger this internal logic error.

Version Disparity: Importing a dump file from a much higher Oracle version into a lower version without using the VERSION parameter correctly. Step-by-Step Solutions 1. Exclude Statistics

The most frequent cause of error [71] is a failure in processing table statistics. You can bypass this by excluding statistics during the import and gathering them manually later. Add this parameter to your impdp command: EXCLUDE=STATISTICS Use code with caution.

If the import succeeds, run DBMS_STATS.GATHER_SCHEMA_STATS after the data is loaded. 2. Recompile Invalids on Source and Target

Data Pump can choke on metadata for objects that are in an INVALID state.

Run utlrp.sql on both the source (before export) and the target database to ensure all objects are valid.

If you cannot re-export, try using EXCLUDE=INDEX or EXCLUDE=CONSTRAINT to see if the worker moves past the error. 3. Use the VERSION Parameter

If you are moving data between different Oracle versions (e.g., 19c to 12c), ensure you used the VERSION parameter during the export (EXPDP). If you didn't, try adding it to your import command: VERSION=12.1 (or your target version) Use code with caution. 4. Check for Corrupt Metadata

Sometimes the error is caused by a specific table. To find out which one, increase the logging detail: TRACE=480300 Use code with caution.

Check the resulting trace files in your DIAGNOSTIC_DEST. Look for the last object processed before the "Fatal Error." You can then try running the import again while excluding that specific table: EXCLUDE=TABLE:"IN ('PROBLEM_TABLE_NAME')" Use code with caution. 5. Patching and Bug 27634993

There is a known Oracle bug related to KUPW$WORKER where imports fail when REMAP_TABLESPACE is used alongside certain partitioned objects.

Workaround: Try performing the import without REMAP_TABLESPACE into a staging area, or check Oracle Support (MOS) for patch 27634993. Summary Checklist Quick Fix: Add EXCLUDE=STATISTICS to your command. Cleanup: Ensure utlrp.sql has been run.

Investigation: Use TRACE=480300 to find the specific table causing the crash.

Dictionary: Check DBA_RESUMABLE to see if the worker is actually stuck on a space issue rather than a logic error.

Immediate Diagnostic Steps

6. Apply latest Oracle patches

Check My Oracle Support for bug fixes related to ORA-39126 and KUPW-WORKER.PREPARE-DATA-IMP. Common patches:

• Patch 20354603 (11.2.0.4)
• Patch 26961325 (12.2)
• Patch 30691174 (19c)