Q2: (5 marks) a) Indexes are data structures that allow finding record ids of records with given values in index search key fields, Explain the types of indexes with the help of some real world example. b) Consider the following transactions; let's assume that the transaction Ti fails, then what would be the value contained in the variable x and y? Does the failure of transaction T1 has any impact on the execution of transaction T2? Justify your answer by providing atleast 5 statements to support the argument. TI T2 read_item (n); read_item(x); x=x*2; X=X-n; write_item(x): n-n*x; write_item(n); read_item (x): read_item(y); x=x+y: y=y+20; write_item(x); Read_item(y); write_item(y)