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  2. Hierarchical database model - Wikipedia

    en.wikipedia.org/wiki/Hierarchical_database_model

    A hierarchical database model is a data model in which the data are organized into a tree-like structure. The data are stored as records which are connected to one another through links. A record is a collection of fields, with each field containing only one value. The type of a record defines which fields the record contains.

  3. Data hierarchy - Wikipedia

    en.wikipedia.org/wiki/Data_hierarchy

    With reference to the example in the above diagram: Data field label = Employee Name or EMP_NAME Data field value = Jeffrey Tan The above description is a view of data as understood by a user e.g. a person working in Human Resource Department. The above structure can be seen in the hierarchical model, which is one way to organize data in a ...

  4. Database model - Wikipedia

    en.wikipedia.org/wiki/Database_model

    Database model for MediaWiki 1.28.0 (2017) Different types of database models. A database model is a type of data model that determines the logical structure of a database. It fundamentally determines in which manner data can be stored, organized and manipulated. The most popular example of a database model is the relational model, which uses a ...

  5. Nested set model - Wikipedia

    en.wikipedia.org/wiki/Nested_set_model

    The nested set model is a technique for representing nested set collections (also known as trees or hierarchies) in relational databases.. It is based on Nested Intervals, that "are immune to hierarchy reorganization problem, and allow answering ancestor path hierarchical queries algorithmically — without accessing the stored hierarchy relation".

  6. Multilevel model - Wikipedia

    en.wikipedia.org/wiki/Multilevel_model

    Multilevel models (also known as hierarchical linear models, linear mixed-effect models, mixed models, nested data models, random coefficient, random-effects models, random parameter models, or split-plot designs) are statistical models of parameters that vary at more than one level. [1]

  7. Hierarchical and recursive queries in SQL - Wikipedia

    en.wikipedia.org/wiki/Hierarchical_and_recursive...

    A hierarchical query is a type of SQL query that handles hierarchical model data. They are special cases of more general recursive fixpoint queries, which compute transitive closures. In standard SQL:1999 hierarchical queries are implemented by way of recursive common table expressions (CTEs).

  8. Bayesian hierarchical modeling - Wikipedia

    en.wikipedia.org/wiki/Bayesian_hierarchical_modeling

    Bayesian hierarchical modelling is a statistical model written in multiple levels (hierarchical form) that estimates the parameters of the posterior distribution using the Bayesian method. [1] The sub-models combine to form the hierarchical model, and Bayes' theorem is used to integrate them with the observed data and account for all the ...

  9. DIKW pyramid - Wikipedia

    en.wikipedia.org/wiki/DIKW_Pyramid

    DIKW is a hierarchical model often depicted as a pyramid, sometimes as a chain, with data at its base and wisdom at its apex (or chain-beginning and -end). [1] [14] [4] [15] Both Zeleny and Ackoff have been credited with originating the pyramid representation, [14] although neither used a pyramid to present their ideas.