The functions of metadata are:
1. Information describing data attributes, used to support functions such as indicating storage location, historical data, resource search, and file recording.
2. Metadata is an electronic catalogue. In order to compile a catalogue, it is necessary to describe and collect the content or characteristics of data in order to assist data retrieval.
Example of metadata application:
1. data structure: the name, relationship, fields and constraints of the data set;
2. Data deployment: the physical location of the data set;
3. Data flow: process dependence (non-referential dependence) between data sets, including rules from one data set to another;
4. Quality metrics: metrics that can be calculated on data sets;
5. Metric logical relationship: the logical operation relationship between data set metrics;
6.ETL process: the sequence of process operations, parallel and serial;
7. Data set snapshot: the data distribution on all data sets at a certain point in time.
Extended data:
Advantages of metadata:
1. Self-description: Metadata automatically provides functions of IDL in COM, allowing a file to be used for definition and implementation at the same time. Runtime modules and assemblies do not even need to be registered with the operating system. Therefore, the instructions used by the runtime always reflect the actual code in the compiled file, thus improving the reliability of the application.
2. Design: Metadata provides all the necessary information about compiling code for users to inherit classes from PE files written in different languages. Users can create instances of any class written in any managed language (any language of the common language runtime) without worrying about explicit marshaling or using custom interoperability code.