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B⁺-tree: introduction

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Slideshow:

What is a B⁺-tree

What does a B⁺-tree look like...

What does a B⁺-tree look like...

What does a B⁺-tree look like...

Terminology
 
Storing a B⁺-tree on disk
 
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• B⁺-tree
  • B⁺-tree:

    B+-tree = an acronym for a tree structure that nobody knows what the acronym stands for.... Possible meaning: Balanced tree (because the tree is balanced Boeing tree (because reportedly, someone working for Boeing developed it)

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  • What is a B⁺-tree:

    B+-tree = a dynamic multi-level index               Organized as a balanced tree structure

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  • Example of a B⁺-tree:

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• Definitions related to a tree in general

  • Definitions:

    Root node = the node at the "top" (or bottom depending how you draw the tree) of the tree Internal node = a node that has one or more child node(s) Leaf node = a node that does not have any children nodes

    Note:

    B+-tree is a height balanced tree: Every leaf node is located at the same distance (height) from the root node

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• Storing a B⁺-tree
  • How to store a B⁺-tree index:

    Each (internal or leaf) node is stored as one disk block

    Example: