How to solve the merge.Matrix() high volume dataset? 360 mil observations

I tried to join two matrix, however the dataset is very high volume. Is there any alternate way to cope with the issue? Otherwise I need to process batch by batch slowly... :disappointed_relieved:

> devtools::session_info()$platform
 setting  value                       
 version  R version 3.5.1 (2018-07-02)
 os       Windows >= 8 x64            
 system   x86_64, mingw32             
 ui       RStudio                     
 language en                          
 collate  Japanese_Japan.932          
 tz       Asia/Tokyo                  
 date     2018-09-16                  
          sysname           release           version          nodename           machine             login 
        "Windows"        ">= 8 x64"      "build 9200" "RSTUDIO-SCIBROK"          "x86-64"           "scibr" 
             user    effective_user 
          "scibr"           "scibr"