How To Fix DDLS_HIER021 - Spantree is not yet supported for hierarchies in CDS

SAP Error Message - Details

• Message type: E = Error

• Message class: DDLS_HIER - Used for DDL Hierarchies

• Message number: 021

• Message text: Spantree is not yet supported for hierarchies in CDS

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

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Smart SAP Assistant

• What is the cause and solution for SAP error message DDLS_HIER021 - Spantree is not yet supported for hierarchies in CDS ?

  The SAP error message DDLS_HIER021 indicates that the use of a "spanning tree" (spantree) is not supported for hierarchies in Core Data Services (CDS) views. This error typically arises when you are trying to create or use a hierarchy in a CDS view that involves a spanning tree structure, which is not currently supported by the CDS framework.
  Cause:
  The primary cause of this error is the attempt to define a hierarchy in a CDS view that utilizes a spanning tree structure. In SAP, hierarchies are often used to represent parent-child relationships, but the CDS framework has certain limitations regarding the types of hierarchies it can handle. Specifically, spanning trees, which allow for multiple paths between nodes, are not supported.
  Solution:
  To resolve this error, consider the following approaches:
  
  
  Review Hierarchy Structure: Ensure that the hierarchy you are trying to implement does not require a spanning tree. You may need to redesign your hierarchy to fit within the constraints of a tree structure, where each child node has only one parent.
  
  
  Use Alternative Data Models: If your data model inherently requires a spanning tree, consider using alternative methods to represent your data. This could involve using standard SQL views or other data modeling techniques that do not rely on CDS hierarchies.
  
  
  Check SAP Notes and Documentation: Always check the latest SAP Notes and documentation for updates or changes regarding CDS view capabilities. SAP frequently updates its software, and there may be new features or workarounds available.
  
  
  Consult SAP Community or Support: If you are unable to resolve the issue, consider reaching out to the SAP Community or SAP Support for assistance. They may provide insights or solutions based on similar experiences from other users.
  
  
  Related Information:
  
  CDS Views: Core Data Services (CDS) is a framework for defining semantically rich data models in SAP. Understanding the limitations and capabilities of CDS is crucial for effective data modeling.
  Hierarchy Types: Familiarize yourself with the different types of hierarchies supported in SAP, such as parent-child hierarchies, and ensure your design adheres to these types.
  SAP Documentation: Refer to the official SAP Help Portal for detailed information on CDS views, hierarchies, and best practices for data modeling.
  
  By following these steps, you should be able to address the DDLS_HIER021 error and successfully implement your data model in SAP.