How to deal with error about memory limitation with biglm function to ffdf object

Question

I have a large ffdf object in R. It contains x and y values, and each column has 71,998,512 values.

I am trying to apply biglm function in biglm package as below

dat <- ffdf(Back = Pitch_Back$V1,  Head = Pitch_Head$V1)            
fit_linear <- biglm(Back ~ Head, data = dat)

But I came across the memory limit error as below;

Error: cannot allocate vector of size 549.3 Mb

How can I deal with it?