The original title is: "Building a B+ Tree Storage Engine (Part 1): Why Order Stops Making Sense on Disk"

Short summary

Building a disk-based B+ tree storage engine, the author discovered that 'order'—the foundational parameter specifying max/min keys per node—becomes meaningless with variable-sized records. Real databases measure node fullness in bytes, not record count, using a slot-directory pattern: store records at the page's end while maintaining a sorted index at the front. This reveals that 'order' is just an abstraction for physical page size, a simplification that disappears when moving from memory to disk.

• •Variable-sized records break the traditional B-tree 'order' metric
• •Real databases use byte-based fullness tracking instead of record counts
• •Slot-directory pattern enables efficient sorted variable-length storage on disk

Generated with AI, which can make mistakes.