harddisk
Generating random keys
Creating tables
Inserting 10000 rows in order
Inserting 10000 rows in reverse order
Inserting 10000 rows in random order
Time for insert (30000): 1111 wallclock secs ( 1.51 usr 0.46 sys + 0.00 cusr 0.00 csys = 1.97 CPU)
Testing update of keys with functions
Time for update_of_key (5000): 110 wallclock secs ( 0.17 usr 0.06 sys + 0.00 cusr 0.00 csys = 0.23 CPU)
Time for update_of_key_big (480): 41 wallclock secs ( 0.03 usr 0.01 sys + 0.00 cusr 0.00 csys = 0.04 CPU)
Testing update with key
Time for update_with_key (30000): 773 wallclock secs ( 1.18 usr 0.41 sys + 0.00 cusr 0.00 csys = 1.59 CPU)
Time for update_with_key_prefix (10000): 240 wallclock secs ( 0.79 usr 0.16 sys + 0.00 cusr 0.00 csys = 0.95 CPU)
Generating random keys
Creating tables
Inserting 10000 rows in order
Inserting 10000 rows in reverse order
Inserting 10000 rows in random order
Time for insert (30000): 785 wallclock secs ( 1.47 usr 0.43 sys + 0.00 cusr 0.00 csys = 1.90 CPU)
Testing update of keys with functions
Time for update_of_key (5000): 123 wallclock secs ( 0.21 usr 0.07 sys + 0.00 cusr 0.00 csys = 0.28 CPU)
Time for update_of_key_big (480): 19 wallclock secs ( 0.03 usr 0.00 sys + 0.00 cusr 0.00 csys = 0.03 CPU)
Testing update with key
Time for update_with_key (30000): 763 wallclock secs ( 1.26 usr 0.40 sys + 0.00 cusr 0.00 csys = 1.66 CPU)
Time for update_with_key_prefix (10000): 258 wallclock secs ( 0.95 usr 0.14 sys + 0.00 cusr 0.00 csys = 1.09 CPU)
结论，在写入方面相差不是很明显，插入大概节省1/3时间，update方面轻微胜出