How To Fix DMC_RT_MSG559 - More than one occurrence of schema node

SAP Error Message - Details

• Message type: E = Error

• Message class: DMC_RT_MSG - DMC: Runtime Object Messages

• Message number: 559

• Message text: More than one occurrence of schema node

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message DMC_RT_MSG559 - More than one occurrence of schema node ?

  The SAP error message DMC_RT_MSG559 ("More than one occurrence of schema node") typically occurs in the context of data migration or data transformation processes, particularly when using SAP Data Migration Cockpit (DMC) or similar tools. This error indicates that there are multiple instances of a schema node that should be unique, leading to ambiguity in the data mapping or transformation process.
  Cause:
  
  Duplicate Entries: The most common cause is that the source data contains duplicate entries for a specific schema node that is expected to be unique.
  Incorrect Mapping: There may be an issue with how the data is mapped from the source to the target, where the schema definition expects a single occurrence but finds multiple.
  Configuration Issues: The configuration of the data migration or transformation process may not align with the expected structure of the data.
  
  Solution:
  
  
  Check Source Data: Review the source data for duplicates. Ensure that the data being migrated does not contain multiple entries for the same schema node.
  
  Use tools like Excel or SQL queries to identify duplicates.
  
  
  
  Adjust Mapping: If the mapping configuration is incorrect, adjust it to ensure that it aligns with the expected schema. This may involve:
  
  Modifying the mapping rules to handle multiple occurrences appropriately.
  Ensuring that the target schema can accommodate the data structure from the source.
  
  
  
  Schema Validation: Validate the schema definitions in both the source and target systems to ensure they are correctly defined and that there are no discrepancies.
  
  
  Data Cleansing: If duplicates are found in the source data, consider implementing data cleansing processes to remove or consolidate duplicate entries before migration.
  
  
  Consult Documentation: Refer to the SAP documentation for the specific data migration tool you are using. There may be specific guidelines or best practices for handling schema nodes and their occurrences.
  
  
  Testing: After making adjustments, conduct thorough testing to ensure that the changes resolve the issue and that the data migration proceeds without further errors.
  
  
  Related Information:
  
  SAP Data Migration Cockpit (DMC): This tool is used for migrating data into SAP systems. Understanding its configuration and capabilities can help in troubleshooting issues like DMC_RT_MSG559.
  Data Quality Management: Implementing data quality checks before migration can help prevent such errors. This includes deduplication processes and validation rules.
  SAP Community and Support: Engaging with the SAP community forums or SAP support can provide additional insights and solutions from other users who may have encountered similar issues.
  
  By following these steps, you should be able to identify the root cause of the DMC_RT_MSG559 error and implement a solution to resolve it.