Memory allocating error with coxph model I'm working with cox models and as I am adding more variables, I am facing a memory issue. I tried to subset my dataframe by selecting columns which have variables of interest but even then I am facing this problem. How can I overcome that?

My data has around 451,557 observations with 270 variables. 70 Percent of variables are categorical (strings).

coxdf_2&lt;- coxph(surv_df ~ NS_group + age_at_recruitment + Gender + Alcohol_drinking + 
                              Smoking + Diabetes + BMI +  +Hypertention, 
                method="breslow", data = DFMODEL)



  Error: cannot allocate vector of size 16.1 Gb


coxdf_3&lt;- coxph(surv_df ~ NS_group + SOC+ towndep_I + Education+age_at_recruitment + 
                          Gender + Alcohol_drinking  + Smoking + Diabetes + BMI +  
                          +Hypertention,
                method="breslow", data = DFMODEL)



  Error: cannot allocate vector of size 24.4 Gb
If you're using a 64-bit version of R on Windows (I'm not sure about other operating systems), then you can allocate additional memory to R with memory.limit function. 

memory.limit(size = 25000) ## limit is set based on Mb


32-bit version (depending on the system, whether it is 32-bit or 64-bit) is limited to 
2 to 4Gb.

You can further read about memory limits in R.

All that said, I would take a step back beforehand to make sure I actually need to deal with all that data and would investigate other alternatives.