I noticed that the database sometimes receive high loads, and checking on the processes shows that it's a query (command) from the fiction's search. This query is locked or is being 'copying to tmp table' and starts to hang there for minutes, up to 30 mins sometimes.

I want to debug this and fix it because it affects the server, not just the person trying to search.

Anyhow, if you search the fiction section and do not receive any results within 20 seconds, it's probably not working properly. Please post here the settings you use for your search query so I can investigate the issue.

Thanks!