example-simple.tex

\documentclass{article}

\usepackage[german]{babel}

% Use btreevis package
\usepackage{btreevis}

\begin{document}
  \begin{center}
  \begin{tikzpicture}[
    % Use default B+ tree style
    BTreeDefault,
    % Sibling and level distance for 1 level.
    % These have to be adapted for almost every B+ tree if
    %   - the number of pointers per node and/or
    %   - the matrix content and/or
    %   - the number of levels and/or
    %   - the number of children
    % changes.
    level 1/.style = {
      sibling distance = 8em,
      level distance = 6em
    }
  ]

    % Set number of pointers per node (this should be done always upfront)
    \SetNoOfPoinersPerNode{4}

    % Generate content of (tree) level 0 (root level)
    \CreateBTreeNode{0}{1}{{3, 9}}{\levelZeroNodeOne}

    % Generate content of (tree) level 1
    \CreateBTreeNode{1}{1}{{1, 2}}{\levelOneNodeOne}
    \CreateBTreeNode{1}{2}{{3, 4, 6}}{\levelOneNodeTwo}
    \CreateBTreeNode{1}{3}{{9, 10}}{\levelOneNodeThree}

    % Generate B+ tree nodes using the previously generated node contents
    \node[BTreeNodeDefault] {\levelZeroNodeOne}
    child { node[BTreeNodeDefault] {\levelOneNodeOne} }
    child { node[BTreeNodeDefault] {\levelOneNodeTwo} }
    child { node[BTreeNodeDefault] {\levelOneNodeThree} };

    % Connect B+ tree nodes (vertical, solid arrows)
    \ConnectBTreeNodes{0}{1}{1}{3}{1}

    % Connect B+ tree leaf nodes (horizontal, dotted arrows)
    \ConnectBTreeLeaves{1}{3}
  \end{tikzpicture}
  \end{center}
\end{document}