04 Try it yourself Interactive

Five operations, two worlds

The same three students from section 02, and the same six steps run twice. Relation applies each operation to the mathematical object: a set of tuples over named attributes. SQL table applies the identical operation to student as created with no primary key and no unique constraint. Watch the four stat boxes rather than the narration if you are short of time: the two runs stay identical until step 2, and the gap between rows stored and distinct tuples never closes again. Nothing plays on its own. Next, Back and Reset, or the arrow keys.

Relation
STUDENT · a set of 3 tuples
Indigo marks the attributes a step is moving. Amber marks a row that repeats one already in the table. A dashed row is a tuple the step is offering, and rose marks whatever the model or the database will not keep as written.
Press Next to begin. Each press applies one operation.


      

        
Degree–

        
Rows stored–

        
Distinct tuples–

        
Duplicate rows0

      


      

      

        
        
        
        step 0 / 0