Actually, I am guessing that even if this cache were to be implemented it wouldn’t have much effect for me, since it would be emptied whenever a page is edited.
Yesterday I hacked up a speedier (but platform specific) search that uses shell_exec in combination with the find / grep linux utilities for searching… down from 15 seconds to 1-2 second searches… still not super fast, but good enough for now
Slap it into some DB. I tried almost everything and if you need something sensible (everybody expects google type of supersmart search) you need lot of things like stemming, ranking, coalition and if its nonenglish language… well you need that even more.
After some time i realized putting it into postgres or mysql was the most performant thing.
I dont like to run db. Sqlite is also great option - you need just install binary and your db is just file. Its also magnitudes faster than flatfile seach.