XML Database

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XML Database

An XML database may be a information persistence package that enables information to be such as, and typically hold on, in XML format. These information will then be queried, reworked, exported and came back to a calling system. XML databases are a flavor of document-oriented databases that are successively a class of NoSQL database (meaning Not (only) SQL).

In databases rationale for XML

There are variety of reasons to directly specify information in XML or alternative document formats like JSON. For XML above all, they include:

  • An enterprise might have lots of XML in AN existing customary format
  • information may have to be exposed or eaten as XML, therefore mistreatment another format like relative forces double-modeling of the information
  • XML is extremely compatible to distributed information, deeply nested information and mixed content (such as text with embedded markup tags)
  • XML is human legible whereas relative tables need experience to access
  • information is commonly offered as XML
  • semantic internet information is out there as RDF/XML

XML Enabled databases
XML enabled databases generally provide one or a lot of of the subsequent approaches to storing XML among the normal relative structure:

  • XML is hold on into a CLOB (Character massive object)
  • XML is `shredded` into a series of Tables supported a Schema
  • XML is hold on into a native XML kind as outlined by ISO customary 9075-14

RDBMS that support the ISO XML kind are:

IBM DB2 (pureXML)
Microsoft SQL Server
Oracle Database
PostgreSQL

Example of XML Type Query in IBM DB2 SQL

SELECT
   id, vol, xmlquery('$j/name', passing journal AS "j") AS name
FROM
   journals
WHERE 
   xmlexists('$j[licence="CreativeCommons"]', passing journal AS "j")

Key options of native XML databases include:

  • Has AN XML document as a minimum of one fundamental unit of (logical) storage, even as a relational database includes a row in an exceedingly table as a elementary unit of (logical) storage.
  • needn’t have any explicit underlying physical storage model. for instance, NXDs will use optimized, proprietary storage formats. this is often a key facet of XML databases. Managing XML as massive strings is inefficient thanks to the additional markup in XML. pressing and indexing XML permits the illusion of directly accessing, querying and remodeling XML whereas gaining the performance benefits of operating with optimized binary tree structures.An XML database may be a information persistence package that enables information to be such as, and typically hold on, in XML format. These information will then be queried, reworked, exported and came back to a calling system. XML databases are a flavor of document-oriented databases that are successively a class of NoSQL database (meaning Not (only) SQL).

 

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