Hello Martin, welcome to the forum and thank you for the question. Others in the team and wider community may have some better suggestions than me, but they’ll almost certainly ask you to share the EXPLAIN ANALYZE for the queries at least. We often recommend using Depesz’s Explain for this because it formats the output in a way that’s much easier to understand. If you could maybe get the output from a sample “bad” query we’ll almost certainly be able to help with some pointers.
It may be Monday before one of our developer advocates gets to this question but bear with us. Let’s see if we can get you on the right track. Meanwhile, here are a couple of links in case they inspire you:
- Foundations videos(especially lesson 7)
- SQL query filtering best practices