Question 1 :
Triggers are stored blocks of code that have to be called in order to operate.
Question 2 :
The joining technique is useful when data from several relations are to be retrieved and displayed and the relationships are not necessarily nested.
Question 3 :
There should be one condition within the WHERE clause for each pair of tables being joined.
Question 4 :
Subqueries can be nested multiple times.
Question 5 :
The code to create triggers and routines is stored in only one location and is administered centrally.