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  2. Nested set model - Wikipedia

    en.wikipedia.org/wiki/Nested_set_model

    The Nested Set model is appropriate where the tree element and one or two attributes are the only data, but is a poor choice when more complex relational data exists for the elements in the tree. Given an arbitrary starting depth for a category of 'Vehicles' and a child of 'Cars' with a child of 'Mercedes', a foreign key table relationship must ...

  3. Quadtree - Wikipedia

    en.wikipedia.org/wiki/Quadtree

    Therefore, we can store the quadtree in a data structure for ordered sets (in which we store the nodes of the tree). We must state a reasonable assumption before we continue: we assume that given two real numbers α , β ∈ [ 0 , 1 ) {\displaystyle \alpha ,\beta \in [0,1)} expressed as binary, we can compute in O ( 1 ) {\displaystyle O(1 ...

  4. Tree (abstract data type) - Wikipedia

    en.wikipedia.org/wiki/Tree_(abstract_data_type)

    In computer science, a tree is a widely used abstract data type that represents a hierarchical tree structure with a set of connected nodes. Each node in the tree can be connected to many children (depending on the type of tree), but must be connected to exactly one parent, [ 1 ] [ 2 ] except for the root node, which has no parent (i.e., the ...

  5. Hierarchical database model - Wikipedia

    en.wikipedia.org/wiki/Hierarchical_database_model

    A hierarchical database model is a data model in which the data is organized into a tree-like structure. The data are stored as records which is a collection of one or more fields . Each field contains a single value, and the collection of fields in a record defines its type .

  6. B+ tree - Wikipedia

    en.wikipedia.org/wiki/B+_tree

    Relational database management systems such as IBM Db2, [11] Informix, [11] Microsoft SQL Server, [11] Oracle 8, [11] Sybase ASE, [11] and SQLite [14] support this type of tree for table indices, though each such system implements the basic B+ tree structure with variations and extensions.

  7. Network model - Wikipedia

    en.wikipedia.org/wiki/Network_model

    While the hierarchical database model structures data as a tree of records, with each record having one parent record and many children, the network model allows each record to have multiple parent and child records, forming a generalized graph structure. This property applies at two levels: the schema is a generalized graph of record types ...

  8. B-tree - Wikipedia

    en.wikipedia.org/wiki/B-tree

    In computer science, a B-tree is a self-balancing tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time. The B-tree generalizes the binary search tree , allowing for nodes with more than two children. [ 2 ]

  9. Tree structure - Wikipedia

    en.wikipedia.org/wiki/Tree_structure

    A tree structure, tree diagram, or tree model is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the classic representation resembles a tree , although the chart is generally upside down compared to a biological tree, with the "stem" at the top and the "leaves" at the bottom.