Keys.txt contains 3287 keys from our database. I ran the first five timed hgetall <keys> on the redis instance after the deletes but before restart: 

[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.621s
user    0m0.088s
sys     0m0.175s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.604s
user    0m0.040s
sys     0m0.084s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.604s
user    0m0.043s
sys     0m0.078s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null
^[[A
real    0m0.601s
user    0m0.047s
sys     0m0.099s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.620s
user    0m0.039s
sys     0m0.087s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.633s
user    0m0.033s
sys     0m0.074s

Ran this on keys.txt after the restart of the instance.
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.370s
user    0m0.093s
sys     0m0.165s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.354s
user    0m0.048s
sys     0m0.101s
[root@ip-10-218-83-236 src]# time /usr/local/bin/redis-cli -p 6382 < ~/keys.txt > /dev/null

real    0m0.352s
user    0m0.041s
sys     0m0.104s