title: Should I decrease the joining tables number but increase the data or reverse
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  <p>I'm still a student, and I have a practical question. I have 4 tables (class {one to many to} subject {one to many to} lecture) and (teacher {one to many to } lecture). If I want to get all classes that some teachers teach in, I have to make 3 inner joins.</p>
  <p>Is it correct to do it that way, or should I connect also (class { one to many } lectures) and by that I would decrease the joins numbers to two, but increase the table field by putting another foreign key. Which is better, to decrease the joining, but increase data, or the reverse?</p>