6 (a) Outline four states of transactions in a database management system. (4 marks) (b) Explain a circumstance under which each of the following anomalies may occur in un normalised database: (i) update; (2 marks) (ii) deletion; (2 marks) (iii) insert. (c) Explain the term data replication as used in Database Management system. (2 marks) (2 marks) (d) A company's database experienced system failure. (i) (ii) Explain two recovery techniques in which the company should have used in order to recover the data. (4 marks) During the recovery, there was a transaction failure. Explain a reason that may have caused each of the following types of errors. 1. Logical errors; II System errors. (4 marks)