Indexaligned

Indexaligned is a term used in computer science to describe a data layout and indexing strategy in which the logical index positions of elements correspond directly to their physical storage order. The goal is to maximize data locality so that traversals by index can be performed with minimal pointer indirection and cache misses.

In an indexaligned design, the primary key index, or a suitable secondary index, is managed so that the i-th element in the index is located near the i-th data block, or even stored contiguously with the data it references. This can be achieved through sorted storage, partitioning schemes that preserve index order, or embedding index metadata within data blocks to maintain alignment.

Benefits of alignment include improved sequential scan performance, better CPU cache utilization, and efficient bulk input/output for range queries. The approach often complements in-memory structures and columnar formats, where predictable access patterns enable faster traversal and, in some cases, vectorized execution.

Challenges include maintaining alignment under frequent updates, which can cause fragmentation and higher write amplification. There are trade-offs between write cost and read performance, and portability concerns across storage media and database engines. Hybrid strategies may adjust the degree of alignment based on workload.

Related concepts include data locality, cache-conscious data structures, and traditional indexing schemes such as B-trees and LSM-trees. Indexaligned designs are discussed in the contexts of high-performance databases, in-memory data grids, and analytics platforms.