An autoloaded option that holds a cache

Every autoloaded option is fetched on every request, and a plugin storing a cache in one turns a cache into a fixed cost.

SELECT option_name, LENGTH(option_value) AS bytes
FROM wp_options
WHERE autoload = 'yes'
ORDER BY bytes DESC
LIMIT 10;

-- 4.1 MB in one row, named *_product_feed_cache

UPDATE wp_options SET autoload = 'no'
WHERE option_name = 'somepluginPREFIX_product_feed_cache';

The total autoloaded size is the number to watch and a healthy site is under about 800 kilobytes; several megabytes is unserialised into PHP memory on every request including admin-ajax and cron. Switching autoload off is safe for anything read on a specific screen and breaks anything read during init without a fallback — so the change wants testing rather than applying to the top ten by size. Tracking the total over time catches the plugin that reintroduces it.