删除一个巨大的(3.5 GB) csv文件以读取到R中

So I've got a data file (semicolon separated) that has a lot of detail and incomplete rows (leading Access and SQL to choke). It's county level data set broken into segments, sub-segments, and sub-sub-segments (for a total of ~200 factors) for 40 years. In short, it's huge, and it's not going to fit into memory if I try to simply read it.So I've got a data file (semicolon separated) t