Database Management System a When two sets are UNIONED toget

Database Management System:

a. When two sets are UNIONED together, duplicate records will not be shown.

True

False   

b. In SQL, I can specifiy a constraint in R such that R.att1 references S.att2 before I build the entity S.

True

False

Solution

a. When two sets are UNIONED together, duplicate records will not be shown.

sol: true (here dulplicate records means where all record in a result contains same coloumn)

b. In SQL, I can specifiy a constraint in R such that R.att1 references S.att2 before I build the entity S.

sol; false because contsraints cannnot be specified before table creation