How the WordPress transient API works, and when wp transient delete actually helps
WordPress ships with a built-in way to store data temporarily — save something for a fixed window of time, and it stops being valid once that window closes. This is the transient API, and both WordPress core and countless plugins lean on it to cache things like external API responses or the results of expensive calculations. It’s a genuinely useful mechanism, but used without understanding how it actually behaves, expired entries can pile up and quietly bloat the database. Note: the transient API is WordPress core’s name for a small set of PHP functions — set_transient(), get_transient(), delete_transient() — built around the idea of a cache entry with an expiration. …