External-sorting

DSAA works

record

• key: float -4bytes
• val: unsigned int -4bytes

block

• 4096 bytes
• 512 records

random_creater

created random records for 8N blocks

./random_creater.exe
>> ...filename: REC.dat
>> ...N: 10

extsort

./extsort.exe REC.dat STAT.dat

get a copy of REC.dat(cp_REC.dat), and REC.dat is sorted.

check_sorted

./check_sorted.exe REC.dat

to check whether REC.dat is sorted.

test

N = 100000
filesize = 3.05GB
cost time = 1.7h