A 2-3 tree is a type of tree-based indexing where each internal node in the tree has either two nodes with one key or three nodes with two keys thus, it is classified as a balanced tree. Also, all the nodes in a 2-3 tree are at the same level of tree height. An example of a two-node structure is shown in Figure 7.10:
Figure 7.10: Example of a two-node tree structure
A two-node structure consists of one key and two children/subtrees. All the keys on the left side are smaller, and all the keys on the right subtree are bigger than the key. Similarly, three-node structure has two keys with three children/subtrees, as shown in Figure 7.11 ...