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Metadata classes

Meta-information is provided via following definition classes:

  • TypeDefinition - provides type definitions for complex data types, keys and enumerations
  • PropertyDefinition - provides property definitions for extents or properties in a complex data type
  • EnumeratorDefinition - provides enumerator definition for enumerators in an enumeration
  • IndexDefinition - provides access key definitions for collections

Meta-information can be read directly from the dictionary database, but in order to improve performance, meta-information is copied into main storage and run-time information is added to internal meta-information.

Internal meta-information objects can be read, but not updated. In order to update meta-information (schema and related resources), metadata has to be accessed directly via property handles opened for the dictionary.

Subtopics

  1. TypeDefinition - Type definition
  2. EnumeratorDefinition - Enumerator instance (category)
  3. PropertyDefinition - Property definition
  4. DBIndex - Index definition