Oracle Data Pump is a utility that performs database export (expdp) and import (impdp) operations. This utility is faster and more flexible than previous versions of the exp and imp utilities.
Directs Oracle Data Pump to skip forward to the start of the next granule when a stream format error is encountered while loading table data. Stream format errors typically are the result of corrupt dump files. If Oracle Data Pump encounters a stream format error, and the original export database is not available to export the table data again, then you can use CONTINUE_LOAD_ON_FORMAT_ERROR. If Oracle Data Pump skips over data, then not all data from the source database is imported, which potentially skips
hundreds or thousands of rows.
Role of the CONTINUE_LOAD_ON_FORMAT_ERROR Option
If a data format error occurs during an Import Data Pump (impdp) operation, instead of rolling back the entire process, you can skip only the portion of data that encountered the error and continue loading from the next portion of data. This option allows the entire process to continue without fail.
When you use the `CONTINUE_LOAD_ON_FORMAT_ERROR` parameter with Oracle Data Pump, it instructs the data pump to skip forward to the start of the next granule when a stream format error is encountered while loading table data. A granule is a unit of work within Oracle Data Pump, and skipping to the next granule allows the data pump to continue processing the remaining data.
Understanding Stream Format Errors
Stream format errors in Oracle Data Pump usually indicate issues with the dump files. These errors can occur due to a variety of reasons, such as:
- Corruption during the export process
- Issues during the transfer of dump files
- Hardware or storage problems
- Software bugs or issues
How to use the CONTINUE_LOAD_ON_FORMAT_ERROR Option
DATA_OPTIONS=CONTINUE_LOAD_ON_FORMAT_ERROR Add options when running the Import Data Pump (impdp) command.
example:impdp system/orcl DIRECTORY=data_pump_dir DUMPFILE=export_1.dmp DATA_OPTIONS=CONTINUE_LOAD_ON_FORMAT_ERROR
Pros and Cons of CONTINUE_LOAD_ON_FORMAT_ERROR Option
Advantages:
This will prevent the entire process from failing and allow you to move on.
You can skip only the portion of data in error and import the remaining data successfully.
Disadvantage:
Data integrity may be compromised because the portion of data in error is not retrieved.
You may need to determine the cause of the error and resolve it.
Additional Information
Oracle Data Pump is used for a variety of purposes, including database migration, backup, and restore. For more information about the data pump utility.
Implications of Using CONTINUE_LOAD_ON_FORMAT_ERROR
While CONTINUE_LOAD_ON_FORMAT_ERROR allows the data pump to continue processing even after encountering format errors, it comes with some significant implications:
- Incomplete Data Import: Since the data pump skips over the data that caused the format error, you risk importing incomplete data into the target database. This can result in missing rows or incomplete data sets, which can be problematic for data integrity and consistency.
- Data Loss: Depending on the extent of the format errors and the number of granules skipped, you might end up losing a significant amount of data from the source database during the import process.
- Data Integrity Concerns: Skipped data can lead to data integrity issues in the target database. Inconsistent or incomplete data can affect the reliability and accuracy of the database, leading to potential problems in data analysis, reporting, and application functionality.
Best Practices and Recommendations
To minimize the risks associated with using CONTINUE_LOAD_ON_FORMAT_ERROR, consider the following best practices:
- Validate Dump Files: Before starting the import process, validate the integrity of the dump files using Oracle Data Pump's CHECKSUM parameter. This can help identify any corrupt or incomplete dump files before they cause format errors during the import.
- Re-export Data: If possible, re-export the table data from the source database to generate new dump files without any format errors. This is the safest and most reliable way to ensure a complete and accurate import of data into the target database.
- Monitor Import Process: Monitor the import process closely and review any errors or warnings generated by Oracle Data Pump. This can help you identify and address any issues promptly, minimizing the impact on data integrity and completeness.
- Backup: Always maintain regular backups of your databases, including both source and target databases. In case of any issues or data loss during the import process, you can restore the databases from the backups to recover the lost or corrupted data.
Conclusion
While CONTINUE_LOAD_ON_FORMAT_ERROR provides a workaround to continue the data import process despite encountering format errors, it should be used cautiously and as a last resort. It's crucial to validate dump files, monitor the import process, and maintain backups to ensure data integrity, completeness, and reliability when using Oracle Data Pump for data import operations.
Please feel free to ask. thank you 🙂
Toufique Khan
