How to avoid expensive virtual column expressions

[Kirk_Masden]

My app is rather bloated and I think my sync times are slow because of how I’ve used virtual columns. This led me to search for tips regarding how to speed things up. Here’s a good one:

Improving performance by getting rid of unnecessary virtual columns Questions

I guess we should publish some general rules of thumb (adding @Derek FYI). I’d say, assuming a PRO plan, and painting in very broad strokes here (there are many differences between SQL and google sheets and excel and …): If you have N tables, assume N/3 seconds of baseline latency Take your largest table in terms of cells (rows * columns) and add 1 second for every 5000 cells In #2, If you have security filters, and they are simple (ANDs, equality or IN conditions) and you use a SQL database,…

I’m sure the advice is very good but I’m having trouble implementing @praveen’s fourth admonition:

Avoid virtual columns with a SELECT and anything but an equality or IN filter condition

To be honest, merely getting my app to do what I want it to do has been difficult for me. Figuring out how to do that efficiently, etc. has added another level of complexity that has been a bit beyond me for the most part.

I’ve found lots of admonitions about avoiding this or avoiding that but what I usual don’t understand is what I might do instead. For example, let’s say I want to be able to display a running count of how many records remain in a set that needs to be worked on. I do that with a SELECT() expression in a virtual column, but I’m not supposed to. So, I’m wondering if “avoid such and such” means that there are workarounds that are more efficient or if it means that one needs to give up on kinds of functionality.

If there’s a tutorial or something with examples of how expensive virtual column expressions can be avoided without losing functionality, I’d love to study it. Depending on the price, I think I’d be willing to pay for such instruction.