Database Indexes Internally: A Deep Dive into Data Structures and Operations
Introduction Database indexes are essential for optimizing query performance in relational databases, acting as lookup tables that dramatically reduce data retrieval times from full table scans to targeted searches.[1][2] Internally, they rely on sophisticated data structures like B-trees and B+ trees to organize keys and pointers efficiently, minimizing disk I/O operations which are often the primary bottleneck in database systems.[3][5] This article explores how indexes work under the hood, from creation and structure to query execution, maintenance, and trade-offs, providing developers and DBAs with the depth needed to design effective indexing strategies. ...