Cloud Computing, Cloud Services are compromise for pricing. On Cloud Server WordPress caching database via plugin is just bad idea to activate for pagespeed. You can enable MySQL cache for performance which we discussed before – of course it needs SSH access. For the shared server, WordPress caching database plugins are not bad because backend is actually nicely tweaked and is a real hardware.
Cloud Server : WordPress Caching Database Via Plugin Is Bad
Why this option is kept in WordPress W3 Total Cache like popular plugins? The option is kept as fallback to speedup on old shared hosting where object cache is not available. On newer Apache with HTTPS with PHP 7, WordPress itself loads very fast. On a good dedicated server (good dedicated does not mean huge cost, we have a list of cheap dedicated servers).
Among the virtualised background, OpenVZ running on good backend is strict no for using WordPress caching database via plugin.
Basically if you have activated real MySQL cache on database server side like described in our guide, such “caching” can significantly confuse PHP and result in variable page loading speeds. If you do not have MySQL cache enabled on database server side – you can try but there is no meaning of not enabling MySQL cache from database server side.
Why Not Use?
Because result is unpredictable as disk, CPU, RAM nothing is physical. MySQL already has cache. WordPress plugin is accessing and writing it on disk. Both has a expiration time, a garbage collection, flushing system. PHP will get confused which offer to take. MySQL cache on database server will override and what PHP will do that depends on version, tweaks etc. We can not see what visitors actually viewing. It is risky for the users with old operating systems and slow connection. On dedicated servers with many cores, faster disk can allow marginal benefit and may need more tweak, test.
So much research not needed, you can keep it off and test a particular page 3 times on
webpagetest.org for a week. Thereafter, you can keep it on and test a particular page 3 times on
webpagetest.org for another week. Results after change a settings often gives psychological pleasure. Also you can try this plugin to test :