GotoMarketGuild, the new async coworking group for business owners who want to help each other take their products to market, find and convince customers, and gain traction. 🚀
Today I worked on a much better search function in https://CustomerPing.ai - just in case you don’t know where your customers hang out on the internet. #buildinpublic
Where can I find a good online course in SQL? I need to understand why a join on a nested subquery is faster than if the subquery contains a where clause.
The course should teach me to understand WHY the database choses a certain plan and what to do about it.
@admin
So, depending on the Query, your WHERE clause could not be using the INDEX to sort / filter the data.
A JOIN (specially a LEFT or RIGHT) is heavily dependent on INDEX to work fast.
Also applying a WHERE clause after a JOIN could be faster because it's doing a sort/filter on a subset of data, not the full table(s)