stringbuilder for test performance 性能 update 性能

写文件,20w数据,文件大小50M,string builder(256)和(512)没有太大的区别,但是整体比string要快上２００ｍｓ.

测试过程中出现了几次stringbuilder比string 慢的现象,,我认为性能上还是stringbuilder 好一些,

stringbuilder 设置256,

sb 256 time:964   str time:1171
sb 256 time:953   str time:1098
sb 256 time:1035   str time:1115
sb 256 time:966   str time:1114
sb 256 time:983   str time:1125
sb 256 time:986   str time:1103
sb 256 time:985   str time:1120
sb 256 time:955   str time:1111
sb 256 time:948   str time:1097
sb 256 time:935   str time:1104
sb 256 time:975   str time:1169
sb 256 time:968   str time:1154
sb 256 time:975   str time:1155
sb 256 time:982   str time:1132
sb 256 time:972   str time:1140
sb 256 time:956   str time:1132
sb 256 time:956   str time:1135
sb 256 time:984   str time:1137
sb 256 time:937   str time:1150

逐行写文件,我改成5000行写一次,效率更低

于是mark 一下  sb  better !

cpu i7600U 16G内存, 512ssd.

昨天测试了  update 语句,20W条数据,,

当时是2000个id 一起,2000个update sql 一起.

update ** set **=** where id=1 连接超时

和update ** set **=** where id in(1,2,3) 耗时 3277 ms 区别明显