# Big O Notation

> A method for classifying an algorithm by the upper bound on how its cost grows with input size, ignoring constant factors.

Record: `architecture:big-o-notation`
Kind: technique
Layer: [Performance Core](https://banes-lab.com/records/layer/performance-core.md)
Severity: contextual
Scope: algorithm
Canonical: https://banes-lab.com/ontology#architecture-big-o-notation

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Space Complexity](https://banes-lab.com/records/architecture/space-complexity.md) and before [Optimization](https://banes-lab.com/records/architecture/optimization.md).

## Repair

- Refactored by: Analyze Complexity, Replace Algorithm
- Detected by: missing complexity note for critical algorithm
- Violated by: ignoring growth behavior for large inputs
- Measured by: asymptotic classification
- Enforced by: review checklist

## Requires

- [Complexity Model](https://banes-lab.com/records/lexicon/complexity-model.md)

## Reinforces

- [Algorithmic Efficiency](https://banes-lab.com/records/architecture/algorithmic-efficiency.md)

## Enables

- [Comparative Analysis](https://banes-lab.com/records/lexicon/comparative-analysis.md)

## Conflicts with

- [Anecdotal Performance Claims](https://banes-lab.com/records/lexicon/anecdotal-performance-claims.md)

## In tension with

- [Constant-Factor Practicality](https://banes-lab.com/records/lexicon/constant-factor-practicality.md)

## Tensions

- [Big O Notation / Constant-Factor Practicality](https://banes-lab.com/records/tension/big-o-notation-constant-factor-practicality.md)

## Severity

- [contextual](https://banes-lab.com/records/vocabulary/severity-contextual.md)

## Category

- [Scalability / Performance / Optimization](https://banes-lab.com/records/architecture-category/scalability-performance-optimization.md)

## Linked from

- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/principles/architecture-category-scalability-performance-optimization.md)
- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/lexicon/lexicon-category-scalability-performance-optimization.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)