Error when operate a huge CSV file.

[changxinjie]

runtime: VirtualAlloc of 8589934592 bytes failed with errno=1455
fatal error: out of memory

runtime stack:
runtime.throw({0x1167e3d?, 0xc57268d000?})
runtime/panic.go:1047 +0x65 fp=0x2874fcb0 sp=0x2874fc80 pc=0xb98825
runtime.sysUsedOS(0xc468800000, 0x200000000)
runtime/mem_windows.go:83 +0x1c5 fp=0x2874fd10 sp=0x2874fcb0 pc=0xb78665
runtime.sysUsed(0x16691e0?, 0x555961b8?, 0xc000680100?)
runtime/mem.go:77 +0x25 fp=0x2874fd30 sp=0x2874fd10 pc=0xb78165
runtime.(*mheap).allocSpan(0x16691e0, 0x100000, 0x0, 0xe8?)
runtime/mheap.go:1340 +0x455 fp=0x2874fdc8 sp=0x2874fd30 pc=0xb88595
runtime.(*mheap).alloc.func1()
runtime/mheap.go:961 +0x65 fp=0x2874fe10 sp=0x2874fdc8 pc=0xb87d65
runtime.systemstack()
runtime/asm_amd64.s:496 +0x48 fp=0x2874fe18 sp=0x2874fe10 pc=0xbc5b88