This proposal advocates for the deprecation of nested metadata attributes within the SDMX Information Model.
Metadata attributes in a metadata structure definition are references to concepts. They can come from any number of concept schemes and can form a hierarchy that is specific to the metadata attribute.
This feature introduces unnecessary complexity that can be addressed through alternative solutions if it is truly needed at all.
Arguments for Deprecation
Inconsistency with Data Representation: In SDMX-JSON data messages, nested metadata structures are not directly reflected. Retrieving basic information like IDs, names, and descriptions requires navigating through the provisioning agreement, dataflow, and data structure definitions before reaching the metadata structure definition itself. This process necessitates array index-based linking, further increasing complexity.
SDMX-CSV: Handling nested metadata attributes in SDMX-CSV data messages necessitates special handling on top of already rather complex rules for multi-lingual and multi-valued attributes. The rules for handling multi-valued child attributes of multi-valued parent attributes are outright horrific.
Common Vocabulary and Redundancy: Contact and address information, a common use case for nested attributes, are better represented using flat attributes like CONTACT_EMAIL as recommended by the Metadata Common Vocabulary and its successor. Rendering software would needlessly need to support variations like CONTACT_EMAIL, CONTACT.CONTACT_EMAIL, and CONTACT.EMAIL.
Inconsistent Hierarchy Representation: Implementers face challenges when a metadata attribute combines concepts from a concept scheme with a parent-child relationship, but these are presented as a flat list within the Metadata Structure Definition (MSD), or vice versa. This inconsistency necessitates arbitrary decisions regarding hierarchical or flat rendering.
Proposed Alternatives
Concept Scheme Reference: Instead of nested hierarchies within metadata attributes, a concept scheme (or a new dedicated hierarchy type) could encompass concepts from other schemes through references. This approach maintains clarity and leverages existing hierarchical structures within concept schemes.
Flattened Attributes: For scenarios like contact information, the use of flat attributes as recommended by the SDMX Glossary offers a simpler and more consistent approach.
Benefits of Deprecation
Deprecating nested metadata attributes will simplify the SDMX Information Model, leading to:
Enhanced Interoperability: A streamlined model will reduce implementation complexity and improve data exchange between different SDMX tools and systems.
Clearer Data Representation: Flattened structures will make data and metadata easier to understand and process.
Reduced Development Burden: Software developers will no longer need to handle the complexities associated with nested attributes.
Conclusion
Nested metadata attributes introduce unnecessary complexity into the SDMX Information Model. This proposal advocates for their deprecation in favor of alternative solutions that leverage concept scheme references and flattened attributes. These changes will promote interoperability, improve data clarity, and reduce development burdens within the SDMX community.
(In doubt, please handle this as a public review comment on SDMX 3.1 once the comment period begins.)
Introduction
This proposal advocates for the deprecation of nested metadata attributes within the SDMX Information Model.
Metadata attributes in a metadata structure definition are references to concepts. They can come from any number of concept schemes and can form a hierarchy that is specific to the metadata attribute.
This feature introduces unnecessary complexity that can be addressed through alternative solutions if it is truly needed at all.
Arguments for Deprecation
CONTACT_EMAILas recommended by the Metadata Common Vocabulary and its successor. Rendering software would needlessly need to support variations likeCONTACT_EMAIL,CONTACT.CONTACT_EMAIL, andCONTACT.EMAIL.Proposed Alternatives
Benefits of Deprecation
Deprecating nested metadata attributes will simplify the SDMX Information Model, leading to:
Conclusion
Nested metadata attributes introduce unnecessary complexity into the SDMX Information Model. This proposal advocates for their deprecation in favor of alternative solutions that leverage concept scheme references and flattened attributes. These changes will promote interoperability, improve data clarity, and reduce development burdens within the SDMX community.
(In doubt, please handle this as a public review comment on SDMX 3.1 once the comment period begins.)