[mastax]

> Make sure you have estimated table metadata turned on, otherwise QGIS will run a bunch of queries to understand your tables I believe.

That fixed it, thanks! Looking at the manual, there is a tip that tells you to turn that on, otherwise it will read the entire table to characterize the geometries... It's a bit mad that the default behavior has it querying potentially gigabytes of information across the network every time you open the app and click a dropdown, with no progress bar. But it's definitely the type of app where you need to read the manual, and it says so right there.

[maptime]

Glad it worked!

It should only do it once per table but if you are dropping and creating tables often it will be making the DB have a heavy workload

I think theirs an assumption within the geo community of read heavy workloads but I could be wrong

[sohnakukkar]

Could you provide more info about your hardware setup and data size? Why do you need hundreds of layers? Which domain you are working on?