computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...

and

data management Data management comprises all disciplines related to handling data as a valuable resource. Concept The concept of data management arose in the 1980s as technology moved from sequential processing (first punched cards, then magnetic tape) to ...

, data mapping is the process of creating

data element In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has: # An identification such as a data element name # A clear data element definition # One or more representation terms ...

mappings between two distinct data models. Data mapping is used as a first step for a wide variety of

data integration Data integration involves combining data residing in different sources and providing users with a unified view of them. This process becomes significant in a variety of situations, which include both commercial (such as when two similar companies ...

tasks, including: * Data transformation or data mediation between a data source and a destination * Identification of data relationships as part of data lineage analysis * Discovery of hidden sensitive data such as the last four digits of a social security number hidden in another user id as part of a data masking or de-identification project *

Consolidation Consolidation may refer to: In science and technology * Consolidation (computing), the act of linkage editing in computing * Memory consolidation, the process in the brain by which recent memories are crystallised into long-term memory * Pulmon ...

of multiple databases into a single database and identifying redundant columns of data for consolidation or elimination For example, a company that would like to transmit and receive purchases and invoices with other companies might use data mapping to create data maps from a company's data to standardized ANSI ASC X12 messages for items such as purchase orders and invoices.

Standards

X12 standards are generic Electronic Data Interchange (EDI) standards designed to allow a company to exchange

data In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpret ...

with any other company, regardless of industry. The standards are maintained by the Accredited Standards Committee X12 (ASC X12), with the

American National Standards Institute The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organ ...

(ANSI) accredited to set standards for EDI. The X12 standards are often called ANSI ASC X12 standards. The W3C introduce
R2RML
as a standard for mapping data in a Relational database to data expressed in terms of the

Resource_Description_Framework The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of ...

(RDF). In the future, tools based on semantic web languages such as

Resource Description Framework The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of ...

(RDF), the

Web Ontology Language The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for vario ...

(OWL) and standardized metadata registry will make data mapping a more automatic process. This process will be accelerated if each application performed metadata publishing. Full automated data mapping is a very difficult problem (see semantic translation).

Hand-coded, graphical manual

Data mappings can be done in a variety of ways using procedural code, creating

XSLT XSLT (Extensible Stylesheet Language Transformations) is a language originally designed for transforming XML documents into other XML documents, or other formats such as HTML for web pages, plain text or XSL Formatting Objects, which may subse ...

transforms or by using graphical mapping tools that automatically generate executable transformation programs. These are graphical tools that allow a user to "draw" lines from fields in one set of data to fields in another. Some graphical data mapping tools allow users to "auto-connect" a source and a destination. This feature is dependent on the source and destination

data element name A data element name is a name given to a data element in, for example, a data dictionary or metadata registry. In a formal data dictionary, there is often a requirement that no two data elements may have the same name, to allow the data element ...

being the same. Transformation programs are automatically created in SQL, XSLT,

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

, or C++. These kinds of graphical tools are found in most ETL (extract, transform, and load) tools as the primary means of entering data maps to support data movement. Examples include SAP BODS and Informatica PowerCenter.

Data-driven mapping

This is the newest approach in data mapping and involves simultaneously evaluating actual data values in two data sources using heuristics and statistics to automatically discover complex mappings between two data sets. This approach is used to find transformations between two data sets, discovering substrings, concatenations,

arithmetic Arithmetic () is an elementary part of mathematics that consists of the study of the properties of the traditional operations on numbers—addition, subtraction, multiplication, division, exponentiation, and extraction of roots. In the 19th c ...

, case statements as well as other kinds of transformation logic. This approach also discovers data exceptions that do not follow the discovered transformation logic.

Semantic mapping

Semantic mapping is similar to the auto-connect feature of data mappers with the exception that a metadata registry can be consulted to look up data element synonyms. For example, if the source system lists ''FirstName'' but the destination lists ''PersonGivenName'', the mappings will still be made if these data elements are listed as

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are ...

in the metadata registry. Semantic mapping is only able to discover exact matches between columns of data and will not discover any transformation logic or exceptions between columns. Data lineage is a track of the life cycle of each piece of data as it is ingested, processed, and output by the analytics system. This provides visibility into the analytics pipeline and simplifies tracing errors back to their sources. It also enables replaying specific portions or inputs of the data flow for step-wise debugging or regenerating lost output. In fact, database systems have used such information, called data provenance, to address similar validation and debugging challenges already.De, Soumyarupa. (2012). Newt : an architecture for lineage based replay and debugging in DISC systems. UC San Diego: b7355202. Retrieved from: https://escholarship.org/uc/item/3170p7zn

References

{{DEFAULTSORT:Data Mapping

Standards

Hand-coded, graphical manual

Data-driven mapping

Semantic mapping

See also

References