I'm working on college work about how query planner uses statistics and makes the most optimal query.
I have read the 57.1. Row Estimation Examples article and I know how's the PostgreSQL calculates the amount of entities taken from the database.
My question about this is, how database specifies which row's must be taken. For example, database calculated that the current query need 1000 entities. But which exactly? How is it determined?
Thank You in advance.