WordPress how to speed up searches? Sphinx, elasticsearch?

Question

MySQL

Introductory:
There is a site on WordPress, basic setup without perversions, wp_posts table about 300k records, MySQL database weighing 2GB. Powerful server.
Problem:
Site search takes more than 15 seconds.
We tried to set up Sphinx using basic instructions from the Internet, the search speeded up, but not significantly.
Tell me where to dig, what to try ElasticSearch, Redis? Who faced similar problems and how did you struggle?

Answer 1

Sphinx searches in milliseconds on such a volume

Answer 2

Or maybe first in the Orthodox way? Indexes, slolog, explan...?

Answer 3

Hey!
https://community.algolia.com/wordpress/
5 minutes to install and configure, speed is instant

Answer 4

have you tried solr-power ?
Solr seems to be up to date with them now.