This week in caching: Redis object cache, the receipts

This week in caching: Redis object cache, the receipts

Real numbers from teams who swapped MySQL transient hell for a persistent object store:

— WooCommerce store, 40k products — moving wp_options autoloaded transients into Redis object cache cut admin TTFB (time to first byte) from 1.8s to 420ms; cart pages stopped hammering the DB on every add.
— Multisite news network — a Redis object cache trimmed queries-per-request from ~290 to ~60, dropping primary DB CPU off the 90% ceiling at peak.
— Membership site — persistent connections via phpredis (not Predis) shaved another 30ms per request vs the PHP client.

The pattern: object cache helps logged-in / dynamic traffic that page cache can't touch. Skip if your site is 100% anonymous and already full-page cached.

Bookmark: measure queries-per-request before and after with Query Monitor — that delta is your real story.