# Selectivity

The fraction of rows expected to satisfy a predicate.

## What is **Selectivity** in a relational database?

**Selectivity** — The fraction of rows expected to satisfy a predicate.

Level: Freelancer · [More Database terms at this level](https://www.ask-codey.com/glossary/subjects/database/freelancer)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/selectivity