Question 76 :
What is the difference between foreign key and reference key ?
Foreign key is the key i.e. attribute which refers to another table primary key. Reference key is the primary key of table referred by another table.
Question 77 :
Can dual table be deleted, dropped or altered or updated or inserted ?
Question 78 :
If content of dual is updated to some value computation takes place or not ?
Question 79 :
If any other table same as dual is created would it act similar to dual?
Question 80 :
For which relational operators in where clause, index is not used ?
<> , like '% ...' is NOT functions, field +constant, field || ''