This article explains the purpose of MySQL's optimizer_switch prefer_ordering_index, shows how it affects ORDER BY and GROUP BY queries with LIMIT, provides code examples and EXPLAIN output, and argues that disabling it often yields better performance for skewed data distributions.
This article examines MySQL’s optimizer_switch ‘prefer_ordering_index’ setting, explains how it influences ORDER BY/GROUP BY queries with LIMIT, demonstrates cases where keeping it ON harms performance due to costly index scans, and provides concrete SQL examples and recommendations to turn it off in most scenarios.
This article explains the purpose of MySQL’s optimizer_switch ‘prefer_ordering_index’, shows how it affects ORDER BY/GROUP BY queries with LIMIT, provides sample tables and procedures, compares EXPLAIN output with the option ON and OFF, and concludes why disabling it is often the safer choice for most workloads.
This article explains the purpose of MySQL's optimizer_switch prefer_ordering_index, shows why the default ON setting can hurt performance with skewed data, and demonstrates with code and EXPLAIN output how turning it OFF can lead to faster queries for ORDER BY and GROUP BY scenarios.
This article explains the purpose of MySQL's optimizer_switch prefer_ordering_index, why the default ON can hurt performance on skewed data, and demonstrates with table creation, data‑loading procedures, and EXPLAIN output how turning the option OFF often yields faster queries.
