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Metadata

Metadata is data that describes data. In Diffusion™ terms it is something that defines the format of a Diffusion topic message.

Diffusion metadata is a generic mechanism for describing message formats regardless of the exact data representation. It describes a message in terms of fields within it and these fields can be grouped into records which themselves can be further subdivided into fields or records or both.

This generic representation of metadata can potentially be used for many different types of message data. For example, metadata can be used to describe a Diffusion record-based message where fields and records have the same meaning but certain constraints exist (for example, nesting of records is not permitted).

The purpose of metadata is to allow for programmatic modeling of data structures. It is used in the following ways:

  • To define the layout of a record so that fields within the record can be addressed by name.

  • To define the layout of the messages used by record topic data in terms of one or more record definitions.