Oh... I just looked at how the current cache clearing works, and I think that might potentially produce disasters on a high-traffic production site.

For some high-traffic sites, the cache is vital to keep the site online, and a cache invalidation will lead to a cache stampede. If we're forcing such a cache invalidation, without even making that obvious in the documentation or giving people a switch to turn it off, we risk breaking such sites. We will not only mess with the in-memory cache, but also with the persistent (Memcached/Redis/...) cache.

I'd like to first investigate whether we cannot just replace the global variable $wp_object_cache that contains the current WP_Object_Cache instance with a sort of dummy cache object that just not stores anything for these commands.

Good points ta.

I'd like to first investigate whether we cannot just replace the global variable $wp_object_cache that contains the current WP_Object_Cache instance with a sort of dummy cache object

That sounds like a great solution, easy to implement and likely to have speed benefits as well. I'll close this PR and create an issue for it on wp-cli/wp-cli.

For some high-traffic sites, the cache is vital to keep the site online, and a cache invalidation will lead to a cache stampede. If we're forcing such a cache invalidation, without even making that obvious in the documentation or giving people a switch to turn it off, we risk breaking such sites. We will not only mess with the in-memory cache, but also with the persistent (Memcached/Redis/...) cache.

Because the underlying utility, Utils\wp_clear_object_cache(), doesn't flush persistent cache, this isn't applicable.

Requesting a second review from @schlessera

I agree that this solves the problem immediately, instead of risking to introduce potential issues through a new mechanism.

However, I will keep the idea of a dummy cache object in mind, as it would move the special cache handling logic from multiple different commands in multiple different repositories into one single, isolated location.