我已经导出600MB +大小的csv文件从PHP和MySQL以类似的方式，你是没有问题。听起来像您的环境设置的问题 - 不是代码或技术的限制。

I have exported 600MB+ sized csv files from PHP and MySQL in a similar way that you are with no issues. Sounds like a problem with your environment settings - not with the code or a limitation of the technologies.