B-Trees — High Fanout for Blocks

B-trees widen nodes to hold many keys/children—designed for disk blocks where reading one block is expensive.

Try this in Python

# Keys per node sorted; children intervals between keys (concept sketch)
node_keys = [10, 20, 30]
# child i covers keys < node_keys[i] (simplified story)
print(len(node_keys) + 1, "child slots in a full B-tree node sketch")

Key takeaways

• Height shrinks because branching factor is large.
• Insertion may split full nodes—like array list doubling but on tree nodes.
• Databases and filesystems lean on B/B+ variants.