您将如何最小化或压缩Core Data sqlite文件大小？

I have a 215MB csv file which I have parsed and stored in core data wrapped in my own custom objects. The problem is my core data sqlite file is around 260MB. The csv file contains about 4.5million lines of data on my city's transit system (bus stop, times, routes etc).I have a 215MB csv file which I have parsed and