Window Help X + Part 2 Please answer all questions and submit your answers as a PDF file called a2.pdf. 1. What is the purpose of normalisation? What problems does normali- sation gets rid of? When is it used? (4 marks] 2. Consider the relational schema R with key (a, b, c) and no alternative keys. Below all its full functional dependencies are listed. R(a, b, c, d, e, f, g, h) {a,c} e b {9, h} {a,b,c} - 1 ga (a) Explain in which normal form the schema is. [3 marks] (b) Normalise schera R above to 3rd Normal Form. Make sure you declare primary and foreign keys correctly whenever you intro- duce a new schema. Also state explicitly which schema(s) are - intermediate and which are purt of the result. [8 marks] 3. What is a transaction in databuses! [2 marks] 4. Explain ONE of the problems that can occur in a database table when transacuons are carried out concurrently. [2 marks]