B-tree: A B-tree is an also called balanced m-way tree. A node of the tree may have many records or key and pointers to children. It is also called as the balanced sort tree. It search its use in external sorting. It is not a binary tree.
B-tree of order m has following properties:
(1) Every node has a maximum of m children and minimum of m/2 children or any number from 2 to maximum.
(2) The no. of keys in a node is one less than its no of children. The arrangement
PO KI PI .... Kn Pn
? ? ?
To TI Tn each Tl is a m-way tree