Can you explain the structure and working principle of a B-tree for data indexing?

A B-tree is a balanced search tree widely used for indexing data in databases and file systems. Its structure and operation principles:

• Node contains multiple keys and child pointers, with the number of keys limited by minimum and maximum values (determined by the order of the tree).
• All leaves are at the same level, ensuring balance.
• When inserting or deleting keys, the tree automatically restructures (splitting or merging nodes) to maintain balance.

Main advantages:

• High branching factor reduces the tree's depth, which decreases the number of disk read operations.
• Works efficiently with large volumes of data that do not fit into RAM.

Example: in a B-tree of order 3, each node can contain from 1 to 2 keys and from 2 to 3 child nodes. When a node overflows, it is split, maintaining balance and search speed.