How to allocate enough memory to join datasets in R

Question

On my oc win10 RAM: 8Mbytes using RStudio, trying to left join two datasets gives the following error:

> final_df <- whole_data %>% left_join(zones,by=c("Country_Transco"))

Error: cannot allocate vector of size 4.6 Mb

> final_df <- zones %>% left_join(whole_data,by=c("Country_Transco"))

Error: cannot allocate vector of size 2.3 Mb

How to allocate enough memory to join datasets in R, given that Rstudio already takes Gb and the whole system style have 2 Gbytes free ?

Even better: using a unique key for the join:

final_df = merge(x = zones, y = whole_data, by.x =  c("Country_Transco","region"), by.y = c("Country_Transco","region"), all.x = TRUE)

Error: cannot allocate vector of size 681 Kb

memory.limit() returns

> memory.limit()
[1] 8086

(8Gb)