Metadata discovery
From Wikipedia, the free encyclopedia
In metadata, metadata discovery is the process of using automated tools to discover the semantics of a data element in data sets. This process usually ends with a set of mappings between the data source elements and a centralized metadata registry.
Metadata discovery is also known as metadata scanning.
Contents |
[edit] Data source formats for metadata discovery
Data sets my be in a variety of different forms including:
- Relational databases
- Spreadsheets
- XML files
- Web services
- Software source code such as Java, C# or C++ classes
- Unstructured text documents such as Microsoft Word or PDF files
[edit] A taxonomy of metadata matching algorithms
There are distinct categories of automated metadata discovery:
[edit] Lexical Matching
- Exact match - where data element linkages are made based on the exact name of a column in a database, the name of an XML element or a label on a screen. For example if a database column has the name "PersonBirthDate" and a data element in a metadata registry also has the name "PersonBirthDate", automated tools can infer that the column of a database has the same semantics (meaning) as the data element in the metadata registry.
- Synonym match - where the discovery tool in not just given a single name but a set of synonym.
- Pattern match - in this case the tools is given a set of lexical patterns that it can match. For example the tools may search for "*gender*" or "*sex*"
[edit] Semantic Matching
Semantic matching attempts to use semantics to associate target data with registered data elements.
- Semantic Similarity - In this algorithm that relies on a database of word conceptual nearness is used. For example the WordNet system can rank how close words are conceptually to each other. For example the terms "Person", "Individual" and "Human" may be highly similar concepts.
[edit] Statistical Matching
Statistical matching uses statistics about data sources data itself to derive similarities with registered data elements.
- Distinct Value Analysis - By analyzing all the distinct values in a column the similarity to a registered data element may be made. For example if a column only has two distinct values of 'male' and 'female' this could be mapped to 'PersonGenderCode'.
- Data distribution analysis - By analyzing the distribution of values within a single column and comparing this distribution with known data elements a semantic linkage could be inferred.
[edit] Vendors
The following vendors (listed in alphabetical order) provide metadata discovery and metadata mapping software and solutions
- IBM
- Masai Technologies (see [1])
- InfoLibrarian Corporation (see [2])
- Revelytix (see [3])
- Sliver Creek Systems (see [4])
- Unicorn Systems (see [5])
- Sypherlink: Harvester (see [6])
- Esquire Innovations (see [7)
[edit] Research
- INDUS project at the University of Iowa (see [7])
[edit] See also
[edit] References
- Massive Data Analysis Systems by San Diego Supercomputer Center June 1997
