wp-performance/references/object-cache.md

Object caching

Use this file when profiling indicates repeated queries or low cache hit rate.

Concepts

• Default WP object cache is per-request memory only.
• A persistent object cache “drop-in” (wp-content/object-cache.php) can persist cache across requests.

WP-CLI cache commands:

• https://wpcli.dev/docs/cache

Guardrails:

• wp cache flush can impact all sites in multisite and cause load spikes:
• https://wpcli.dev/docs/cache/flush

Fix patterns

• Cache expensive computed results (transients or object cache) with explicit invalidation.
• Avoid unbounded caches (set expirations or implement invalidation hooks).
• If adding a persistent object cache, coordinate with infra (Redis/Memcached) and test cache flush behavior.