arrow_back Are all conditions, for virtual tables, written in the virtual table parameter? Or not all of them?

Question

In the video I heard such a remark that in virtual tables it is correct to write a condition in its parameters, but I tried to write a condition in the Conditions tab, everything seems to work the same, what is the difference? Which conditions are written in the parameters and which ones in the Conditions tab, if both work?

Comments

I advise to understand in more detail what virtual tables are and how they work.

Answer 1

The point is that a virtual table is virtual because it does not exist in the database. A virtual table is a selection that is formed from a physical table at the moment of access.
When you write conditions "in the conditions tab", you run a query that pulls a virtual table from the database, with all the data, including the ones you don't need. And then this selection is made according to the conditions.
When you specify conditions in the parameters of the virtual table, it is immediately selected with your conditions in mind. Thus, there is less load on the server, fewer requests, less memory is wasted, users work faster, everyone is happy, and you are good.