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)

## █ [1:0x5cec5efa1d10] <tibble[,24]> 
## ├─Date=[2:0x5cec5cf84c00] <date> 
## ├─Location=[3:0x5cec619039e0] <chr> 
## ├─MinTemp=[4:0x5cec68510090] <dbl> 
## ├─MaxTemp=[5:0x5cec6372e500] <dbl> 
## ├─Rainfall=[6:0x5cec6372f0b0] <dbl> 
## ├─Evaporation=[7:0x5cec646037a0] <dbl> 
## ├─Sunshine=[8:0x5cec64604350] <dbl> 
## ├─WindGustDir=[9:0x5cec6393a7c0] <ord> 
## ├─WindGustSpeed=[10:0x5cec6393adb0] <dbl> 
## ├─WindDir9am=[11:0x5cec6393b960] <ord> 
## ├─WindDir3pm=[12:0x5cec628a5aa0] <ord> 
## ├─WindSpeed9am=[13:0x5cec628a6090] <dbl> 
## ├─WindSpeed3pm=[14:0x5cec59c15630] <dbl> 
## ├─Humidity9am=[15:0x5cec628a6c40] <int> 
## ├─Humidity3pm=[16:0x5cec59c161e0] <int> 
## ├─Pressure9am=[17:0x5cec5fa6a990] <dbl> 
## ├─Pressure3pm=[18:0x5cec5fa6b540] <dbl> 
## ├─Cloud9am=[19:0x5cec59c167d0] <int> 
## ├─Cloud3pm=[20:0x5cec5970f420] <int> 
## ├─Temp9am=[21:0x5cec5970fa10] <dbl> 
## ├─Temp3pm=[22:0x5cec5ff901c0] <dbl> 
## ├─RainToday=[23:0x5cec597105c0] <fct> 
## ├─RISK_MM=[24:0x5cec5ff90d70] <dbl> 
## └─RainTomorrow=[25:0x5cec6492d030] <fct>

lobstr::ref(ds)

## █ [1:0x5cec63b9c270] <tibble[,24]> 
## ├─date=[2:0x5cec5c8d8300] <date> 
## ├─location=[3:0x5cec5f0cfb30] <chr> 
## ├─min_temp=[4:0x5cec5f28ad10] <dbl> 
## ├─max_temp=[5:0x5cec5e86c560] <dbl> 
## ├─rainfall=[6:0x5cec5ea27740] <dbl> 
## ├─evaporation=[7:0x5cec5ebf7580] <dbl> 
## ├─sunshine=[8:0x5cec5edb2760] <dbl> 
## ├─wind_gust_dir=[9:0x5cec5cea6a70] <ord> 
## ├─wind_gust_speed=[10:0x5cec5f58a0a0] <dbl> 
## ├─wind_dir_9am=[11:0x5cec5efd3690] <ord> 
## ├─wind_dir_3pm=[12:0x5cec5f451eb0] <ord> 
## ├─wind_speed_9am=[13:0x5cec5f745280] <dbl> 
## ├─wind_speed_3pm=[14:0x5cec5e33f940] <dbl> 
## ├─humidity_9am=[15:0x5cec5f900460] <int> 
## ├─humidity_3pm=[16:0x5cec5ca934e0] <int> 
## ├─pressure_9am=[17:0x5cec5e4fab20] <dbl> 
## ├─pressure_3pm=[18:0x5cec601afda0] <dbl> 
## ├─cloud_9am=[19:0x5cec5d2d2e80] <int> 
## ├─cloud_3pm=[20:0x5cec5dd42750] <int> 
## ├─temp_9am=[21:0x5cec6036af80] <dbl> 
## ├─temp_3pm=[22:0x5cec60526160] <dbl> 
## ├─rain_today=[23:0x5cec606e1340] <fct> 
## ├─risk_mm=[24:0x5cec60d3eff0] <dbl> 
## └─rain_tomorrow=[25:0x5cec5e6b5d00] <fct>

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