Consider the following log sequence of two transactions on a bank account, with initial balance 12000, that transfer 2000 to a mortgage payment and, then apply a 5% interest i
.i> T1 start
ii>T1 B old = 12000 new = 10000
iii. T1 M old = 0 new = 2000
iv. T1 commit
v. T2 start
vi. T2 B old = 10000 new = 10500
vii. T2 commit
Suppose the database system crashed just before log record 7 is written. When the system is restarted, which one statement is true of the recovery procedure??
a>undo log recoed 6 set B to 10000 and then redo log record 2 and 3
b>need not redo log record 2 and 3 because transaction T1 has already committed.
