I know that R is not particularly helpful for analysing large datasets given that R loads all the data in memory whereas something like SAS does sequential analysis. That said, there are packages like bigmemory that allows users to perform large data analysis (statistical analysis) more efficiently in R.
I wanted to know, apart from all the theoretical information, has anyone used / is using R for analysing large datasets in an enterprise environment and what are the typical issues that could arise. By large datasets I am referring to datasets that are ~ 200 GB in size. Also, any thoughts on real-life examples of migrating from SAS to R in such use cases would be helpful.