Introduction to Database Management System

Questions

f. What is the name of the standard Java API to a database? - g. Suppose a relation schema has attributes {a,bc,d,e}. If {a,b} is a candidate key for the schema, then is {a,b,d) also a candidate key? (yes or no) h. Can a relation schema have two primary keys? (yes or no)_ i. Fill in the blank: every operation of relation algebra produces as output. j. When union is applied to two tables, the tables have to be compatible. In what sense do they have to be compatible? k. In many programming languages there are functions that will append one list to another list. Compare the 'union' operation of relational algebra with the append function by giving one way in which they are different