10.41 Effect on Data Storage

20180721 When the names of the variables within a dataset are changed R does not make a complete new copy of the dataset. Instead, the actual data in the column remains in tack whilst the variable itself (ds) references a new memory location where the new variable names get noted. The underlying data within the table is unaffected.

lobstr::ref(weather)

## █ [1:0x608f4f304620] <tibble[,24]> 
## ├─Date=[2:0x608f4d7d4a30] <date> 
## ├─Location=[3:0x608f54e9d510] <chr> 
## ├─MinTemp=[4:0x608f4f303970] <dbl> 
## ├─MaxTemp=[5:0x608f4eb6e7c0] <dbl> 
## ├─Rainfall=[6:0x608f57054190] <dbl> 
## ├─Evaporation=[7:0x608f4eada8f0] <dbl> 
## ├─Sunshine=[8:0x608f443fa750] <dbl> 
## ├─WindGustDir=[9:0x608f504aaed0] <ord> 
## ├─WindGustSpeed=[10:0x608f495ce1f0] <dbl> 
## ├─WindDir9am=[11:0x608f5627b030] <ord> 
## ├─WindDir3pm=[12:0x608f5627b620] <ord> 
## ├─WindSpeed9am=[13:0x608f4f7c5e30] <dbl> 
## ├─WindSpeed3pm=[14:0x608f57743fb0] <dbl> 
## ├─Humidity9am=[15:0x608f4c3114e0] <int> 
## ├─Humidity3pm=[16:0x608f4c311ad0] <int> 
## ├─Pressure9am=[17:0x608f4809f900] <dbl> 
## ├─Pressure3pm=[18:0x608f44a86220] <dbl> 
## ├─Cloud9am=[19:0x608f4db23d20] <int> 
## ├─Cloud3pm=[20:0x608f4db24310] <int> 
## ├─Temp9am=[21:0x608f495c2ab0] <dbl> 
## ├─Temp3pm=[22:0x608f4be88430] <dbl> 
## ├─RainToday=[23:0x608f4f8bd270] <fct> 
## ├─RISK_MM=[24:0x608f4b382fa0] <dbl> 
## └─RainTomorrow=[25:0x608f4f8bd860] <fct>

lobstr::ref(ds)

## █ [1:0x608f58aa4460] <tibble[,24]> 
## ├─date=[2:0x608f505b51d0] <date> 
## ├─location=[3:0x608f4f924560] <chr> 
## ├─min_temp=[4:0x608f51d4dd70] <dbl> 
## ├─max_temp=[5:0x608f51f67c40] <dbl> 
## ├─rainfall=[6:0x608f50c5d1f0] <dbl> 
## ├─evaporation=[7:0x608f50e770c0] <dbl> 
## ├─sunshine=[8:0x608f51090f90] <dbl> 
## ├─wind_gust_dir=[9:0x608f4fb3e430] <ord> 
## ├─wind_gust_speed=[10:0x608f528c8790] <dbl> 
## ├─wind_dir_9am=[11:0x608f512aae60] <ord> 
## ├─wind_dir_3pm=[12:0x608f50955bf0] <ord> 
## ├─wind_speed_9am=[13:0x608f52ae2660] <dbl> 
## ├─wind_speed_3pm=[14:0x608f52cfc530] <dbl> 
## ├─humidity_9am=[15:0x608f52f16400] <int> 
## ├─humidity_3pm=[16:0x608f53023380] <int> 
## ├─pressure_9am=[17:0x608f53130300] <dbl> 
## ├─pressure_3pm=[18:0x608f5334a1d0] <dbl> 
## ├─cloud_9am=[19:0x608f535640a0] <int> 
## ├─cloud_3pm=[20:0x608f53671020] <int> 
## ├─temp_9am=[21:0x608f5377dfa0] <dbl> 
## ├─temp_3pm=[22:0x608f53997e70] <dbl> 
## ├─rain_today=[23:0x608f53bb1d40] <fct> 
## ├─risk_mm=[24:0x608f53cbecc0] <dbl> 
## └─rain_tomorrow=[25:0x608f53ed8b90] <fct>

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