Suppose that a disk unit has the following parameters: seek time $s=20$msec; rotational

delay $rd=10$msec; block transfer time $btt=1$msec; block size $B=1024$ bytes; interblock

gap size $G=300$ bytes. An EMPLOYEE file has the following fields: Ssn$,10$ bytes;

Page $2$ of $6$

Last$\_$name, $30$ bytes; First$\_$name, $10$ bytes; Birth$\_$date, $10$ bytes; Address, $35$ bytes;

Phone, $12$ bytes; Supervisor$\_$ssn$,8$ bytes; Department, $5$ bytes; Job$\_$code, $5$ bytes;

deletion marker, $1$ byte. The EMPLOYEE file has $r=10,000$ records, fixed$-$length format,

and unspanned blocking. Write appropriate formulas and calculate the following values

for the above EMPLOYEE file:

a$)$ The record size $R,$ the blocking factor $bfr,$ and the number of disk blocks $b.(2$

Marks$)$

b$)$ Calculate the wasted space in each disk block because of the unspanned

organization. $(1$ Marks$)$

c$)$ Calculate the transfer rate tr for this disk unit. $(2$ Marks$)$

d$)$ Suppose that the file is ordered by the key field Ssn and we want to construct a

primary index on Ssn$.$ Calculate the number of levels needed if we make it into a

multilevel index $(4$ Marks$)$