<ul><li>Common Warehouse Metamodel </li></ul>
Meta data : data describing data Mata data is critical to achieving integration between dissimilar software systems and pr...
Why meta data A given software product(eg Relational database system  can  perform operations on data effectively only if ...
Relational ware house OLAP ware house metadata metadata interchange Data ware housing/business analysis domain’s
However it is nearly impossible for commercial software products &  Systems to share meta data. Why Most products coming f...
Bridges:  not  good enough Why Time consuming Costly Not reused in other integration  efforts What are we  expecting  then...
A C B products meta data CWM Metamodel (shared meta data) CWM meta data interchange (based on XML or api calls)
Course table and its values courseID  Instructor  Room no Course Table instance Relational table model EE111 Dr.Borie Cs60...
<ul><li>UML (PIM) </li></ul><ul><li>SQL DDL (PSM) </li></ul><ul><li>CRATE TABLE Course( </li></ul><ul><li>ID  VARCHAR NOT ...
CWM components 1. A formal language capable of specifying meta data in terms of shared, platform-independent models. 2. A ...
<ul><li>CWM </li></ul><ul><li>A primary objective of the CWM is to define a metamodel  </li></ul><ul><li>of a generic data...
UML CWM is expressed in UML CWM extends subset of UML language to include data warehousing and business analysis domain co...
 
MOF MOF specification consists of MOF model  : Defines the modeling elements, including the rules for their use, which can...
 
XMI This specifications allow data warehouse metadata based on CWM metamodel to be interchanged using W3C’s Extensible Mar...
XMI XML MOF UML DTD CWM DTD MOF DTD UML Models CWM metadata MOF meta models XML DTD XML documents validate DTD <!element c...
 
<ul><li>The model elements are  contained in the following packages: </li></ul><ul><li>ObjectModel package </li></ul><ul><...
<ul><li>Foundation package </li></ul><ul><li>•  Business Information package </li></ul><ul><li>Contains classes and associ...
<ul><li>Resource package </li></ul><ul><li>•  Relational package </li></ul><ul><li>Contains classes and associations that ...
<ul><li>•  OLAP package </li></ul><ul><li>Contains classes and associations that represent metadata of on-line analytical ...
core relationships
MOF Model XMI UML MetaModel CWM Data Mining JMI JDMAPI Mapping to XML Mapping to java instance of instance of instance of ...
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Common Warehouse Metamodel Meta data : data describing data

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Common Warehouse Metamodel Meta data : data describing data

  1. 1. <ul><li>Common Warehouse Metamodel </li></ul>
  2. 2. Meta data : data describing data Mata data is critical to achieving integration between dissimilar software systems and products from multiple vendors. Product/ component Product/ component metadata metadata Data warehousing & business analysis domain’s component Posses rich meta data
  3. 3. Why meta data A given software product(eg Relational database system can perform operations on data effectively only if it has a precise definition of that data available. Internal meta model Several software products can be integrated effectively only if they have a common understanding of their data External meta model Most products have differing or incompatible internal meta models and interfaces exposing their meta data
  4. 4. Relational ware house OLAP ware house metadata metadata interchange Data ware housing/business analysis domain’s
  5. 5. However it is nearly impossible for commercial software products & Systems to share meta data. Why Most products coming from different vendors have dissimilar meta data Models(or meta models) and interfaces exposing their meta data. So what do we need Bridges between dissimilar meta models. A C B products Meta data Bridges
  6. 6. Bridges: not good enough Why Time consuming Costly Not reused in other integration efforts What are we expecting then A single, low cost, meta data integration architecture. It is simply not possible to have a single metadata repository that implements a single meta model for all the metadata. Instead, what is needed is a standard for interchange of warehouse metadata.
  7. 7. A C B products meta data CWM Metamodel (shared meta data) CWM meta data interchange (based on XML or api calls)
  8. 8. Course table and its values courseID Instructor Room no Course Table instance Relational table model EE111 Dr.Borie Cs601 EE112 Dr.Hawker Cs630
  9. 9. <ul><li>UML (PIM) </li></ul><ul><li>SQL DDL (PSM) </li></ul><ul><li>CRATE TABLE Course( </li></ul><ul><li>ID VARCHAR NOT NULL, </li></ul><ul><li>Instructor CHAR </li></ul><ul><li>Roomno CHAR ); </li></ul><ul><li>Export Mapping : process that translates its internal meta data into a platform independent model </li></ul><ul><li>Import Mapping : process ro transilate model into an instance of its own, product specific data </li></ul><ul><li>Note: If we consider an other relational table modle such as DEPARTMENTS , any software that understands the common metamodel defining relational tables in general can understand both COURSE and DEPARTMENT table models, both of which are instances of the same metamodel. </li></ul>maps
  10. 10. CWM components 1. A formal language capable of specifying meta data in terms of shared, platform-independent models. 2. A common metamodel defining the problem domain. 3. A common interchange format for interchanging shared meta data 4. A common programming interface for meta data access 5. Standard mechanism for extending the metamodels. 6. Software adapters facilitating products meta data import & export CWM is targeted at six categories of users: • Warehouse platform and tool vendors • Professional service providers • Warehouse developers • Warehouse administrators • End users • Information technology managers
  11. 11. <ul><li>CWM </li></ul><ul><li>A primary objective of the CWM is to define a metamodel </li></ul><ul><li>of a generic data warehouse architecture. </li></ul><ul><li>CWM metamodel defines formal rules for modeling instances of data </li></ul><ul><li>warehouses. </li></ul><ul><li>CWM metamodel should be expressed in MOF (and thus </li></ul><ul><li>enabled for interchange via either CORBA interfaces or XMI). </li></ul><ul><li>The main purpose of CWM is to enable easy interchange of warehouse </li></ul><ul><li>and business intelligence metadata between warehouse tools, </li></ul><ul><li>warehouse platforms and warehouse metadata repositories in distributed </li></ul><ul><li>heterogeneous environments. CWM is based on three key industry </li></ul><ul><li>standards: </li></ul><ul><li>• UML - Unified Modeling Language, an OMG modeling standard </li></ul><ul><li>• MOF - Meta Object Facility, an OMG metamodeling and metadata </li></ul><ul><li>repository standard </li></ul><ul><li>• XMI - XML Metadata Interchange, an OMG metadata interchange </li></ul><ul><li>standard </li></ul>
  12. 12. UML CWM is expressed in UML CWM extends subset of UML language to include data warehousing and business analysis domain concepts through extension mechanism. The UML notation is used in the diagrammatic representations of the CWM metamodel. The CWM metamodel includes an Object Model package which is based on the UML metamodel. Any metaclass within CWM ultimately inherits from some metaclass of the Object Model. Ex. CWM Relational Package Relational metamodel defines a metaclass called &quot;Table&quot; that represents any Relational database table. This metaclass derives from the Object Model metaclass &quot;Class&quot;. Similarly, the Relational metaclass &quot;Column&quot; derives from the Object Model &quot;Attribute&quot;.
  13. 14. MOF MOF specification consists of MOF model : Defines the modeling elements, including the rules for their use, which can be used to construct meta models MOF reflective interfaces . Allows a program to create, update, access, navigate, and invoke operations on meta data . MOF to IDL mapping . Defines the standard mapping from a meta model defined using the MOF model onto CORBA IDL, thus allowing the automatic generation of metamodel specific interfaces for accessing and manipulating meta data (M1 level ) MOF enables dissimilar metamodels representing different domain To be used in an interoperable manner. CWM IDL Java/c++ MOF compliant metamodel, CWM Maps using MOF specification IDL compilar
  14. 16. XMI This specifications allow data warehouse metadata based on CWM metamodel to be interchanged using W3C’s Extensible Markup Language (XML). XMI is used • to transform the CWM metamodel into a CWM Document Type Definition (DTD), • to transfer instances of warehouse metadata that conform to the CWM metamodel as XML documents, based on the CWM DTD, and • to transform the CWM metamodel itself into an XML document, based on the MOF DTD, for interchange between MOF-compliant repositories. --XMI allows MOF meta data, that is meta data that conforms to MOF based metamodel, to be interchanged as streams or files with a Standard format based on XML. --XML defines how XML tags are to be used to store CWM metamodel instances in XML document
  15. 17. XMI XML MOF UML DTD CWM DTD MOF DTD UML Models CWM metadata MOF meta models XML DTD XML documents validate DTD <!element course( Courseid, Instructor Roomno)> XML <course> <courseid>cs630 </courseid> <instructor>Dr. Hawker </instructor> <Roomno> ee111 </Roomno> </course>
  16. 19. <ul><li>The model elements are contained in the following packages: </li></ul><ul><li>ObjectModel package </li></ul><ul><li>• Core package </li></ul><ul><li>Contains classes and associations that form the core of the CWM object model, which are used by all other CWM packages including other ObjectModel packages. </li></ul><ul><li>• Behavioral package </li></ul><ul><li>Contains classes and associations that describe the behavior of CWM objects and provide a foundation for describing the invocations of defined behaviors. </li></ul><ul><li>• Relationships package </li></ul><ul><li>Contains classes and associations that describe the relationships between CWM object. </li></ul><ul><li>• Instance package </li></ul><ul><li>Contains classes and associations that represents instances of CWM classifiers. </li></ul>
  17. 20. <ul><li>Foundation package </li></ul><ul><li>• Business Information package </li></ul><ul><li>Contains classes and associations that represent business information about model elements. </li></ul><ul><li>• Data Types package </li></ul><ul><li>Contains classes and associations that represent constructs that modelers can use to create the specific data types they need. </li></ul><ul><li>• Expressions package </li></ul><ul><li>Contains classes and associations that represent expression trees. </li></ul><ul><li>• Keys and Indexes package </li></ul><ul><li>Contains classes and associations that represent keys and indexes. </li></ul><ul><li>• Software Deployment package </li></ul><ul><li>Contains classes and associations that represent how software is deployed in a data warehouse. </li></ul><ul><li>• Type Mapping package </li></ul><ul><li>Contains classes and associations that represent mapping of data types between different systems. </li></ul>
  18. 21. <ul><li>Resource package </li></ul><ul><li>• Relational package </li></ul><ul><li>Contains classes and associations that represent metadata of relational data resources. </li></ul><ul><li>• Record package </li></ul><ul><li>Contains classes and associations that represent metadata of record data resources. </li></ul><ul><li>• Multidimensional package </li></ul><ul><li>Contains classes and associations that represent metadata of multidimensional data resources. </li></ul><ul><li>• XML package </li></ul><ul><li>Contains classes and associations that represent metadata of XML data resources. </li></ul><ul><li>Analysis package </li></ul><ul><li>• Transformation package </li></ul><ul><li>Contains classes and associations that represent metadata of data transformation tools. </li></ul>
  19. 22. <ul><li>• OLAP package </li></ul><ul><li>Contains classes and associations that represent metadata of on-line analytical processing tools. </li></ul><ul><li>• Data Mining package </li></ul><ul><li>Contains classes and associations that represent metadata of data mining tools. </li></ul><ul><li>• Information Visualization package </li></ul><ul><li>Contains classes and associations that representing metadata of information visualization tools. </li></ul><ul><li>• Business Nomenclature package </li></ul><ul><li>Contains classes and associations that represent metadata on business taxonomy and glossary. </li></ul><ul><li>Management package </li></ul><ul><li>• Warehouse Process package </li></ul><ul><li>Contains classes and associations that represent metadata of warehouse processes. </li></ul><ul><li>• Warehouse Operation package </li></ul><ul><li>Contains classes and associations that represent metadata of results of warehouse operations. </li></ul>
  20. 23. core relationships
  21. 24. MOF Model XMI UML MetaModel CWM Data Mining JMI JDMAPI Mapping to XML Mapping to java instance of instance of instance of extends Relationships between OMG MDA and J2EE Mapping to java

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