Very bad performance with "Retrieve from server"?

It’s definitely not normal, the SQL query/queries (there may be two if you’ve enabled both options under “Autocomplete settings” in the search server settings) seem(s) to be especially slow on your site. Since no-one else has complained yet (as far as I remember), this seems to be specific to your setup, though, so not sure how much I can help you with that. Try debugging first to see whether it’s really the SQL queries that are the problem (e.g., by activating your SQL server’s slow query log) and, if so, debugging them to see how you might be able to improve their performance.

If you are not a developer, there are even less options. If you have both of the mentioned options enabled, you could try whether using just one of them helps with the performance.

However, it might also be that 30,000 nodes is just a bit much for this functionality in the DB backend. Normally, I’d say this is well into the territory where using Solr makes more sense.

We also have a similar issue on a SOLR 7.x server with about 100k Search API Items.
Looking for solutions too.

One option that seems to work better is to use the "Solr Suggester" (but this requires SOLR).

@drunken monkey Thanks for the very quick reply.

Unfortunately the problem is on a project of a company I am not longer working with, therefore I can't actually debug it anymore to gather more data.
I don't know if you may want to close this issue or leave it open in case others devs could provide more insights.

@Giuseppe87: Thanks for reporting back.
I guess we can leave this open in case someone has a similar problem.