App Performance (>10k row apps)

My points of view:

  • can they really be used to speed up an app for some of its users?

Absolutely!.. Row Owners is a kind of filter and will help you to load a more specific data associated to a user, your APP will be lighter.
E.g., why do we have to load 10k rows associated to all customers’ sales when a normal user will verify or use only 3-5 rows of those 10k rows?

  • Reduce the edit count compared to a Google Sheets source

I’d say yes. There are fewer syncs from external sources using GT instead. Also, Glide will love you due to there will be less cost and payments to Google, Microsoft, etc

Working with GT is faster than with GS and you will see the difference the more data your GS has

  • is there any ranking as to which types of computed columns take longer than others or which to avoid in big apps?

I don’t think there is a list of good/bad computed columns, the problem is how you use them and how many you have created to get a result. Sometimes, there are clever solutions/ideas and you only create 2-3 columns to get what you want but sometimes, the no-code tool isn’t enough and smart and makes you to create 5-6 columns to have a simple result (true/false).
These additional columns will cause performance issues when you data exceeds 1k-2k rows probably.
Here an example about it…

  • Single Self Relations are they really a bad practice?

I’d say yes again. I have seen it several times by accident testing things. It’s similar to using VLOOKUP() formula in the same GS searching cells/values among thousands of rows.
If you have too many rows, the sheet gets heavy and crashes sometimes when a row is added/removed or even when other columns have new values

I use a self-referencing relationship as plan B and if my table is small.