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)

## █ [1:0x61cb734dfe30] <tibble[,24]> 
## ├─Date=[2:0x61cb74cf6aa0] <date> 
## ├─Location=[3:0x61cb72e18a40] <chr> 
## ├─MinTemp=[4:0x61cb7eddc660] <dbl> 
## ├─MaxTemp=[5:0x61cb7426b370] <dbl> 
## ├─Rainfall=[6:0x61cb747cdff0] <dbl> 
## ├─Evaporation=[7:0x61cb6c7481b0] <dbl> 
## ├─Sunshine=[8:0x61cb6f28e140] <dbl> 
## ├─WindGustDir=[9:0x61cb7471b420] <ord> 
## ├─WindGustSpeed=[10:0x61cb7302eb40] <dbl> 
## ├─WindDir9am=[11:0x61cb750c8910] <ord> 
## ├─WindDir3pm=[12:0x61cb7403bea0] <ord> 
## ├─WindSpeed9am=[13:0x61cb746d7850] <dbl> 
## ├─WindSpeed3pm=[14:0x61cb731df810] <dbl> 
## ├─Humidity9am=[15:0x61cb743f24b0] <int> 
## ├─Humidity3pm=[16:0x61cb74f91110] <int> 
## ├─Pressure9am=[17:0x61cb7160b710] <dbl> 
## ├─Pressure3pm=[18:0x61cb74f4b480] <dbl> 
## ├─Cloud9am=[19:0x61cb6f2fe500] <int> 
## ├─Cloud3pm=[20:0x61cb6e3b1110] <int> 
## ├─Temp9am=[21:0x61cb6ea79810] <dbl> 
## ├─Temp3pm=[22:0x61cb735e77b0] <dbl> 
## ├─RainToday=[23:0x61cb74fcde70] <fct> 
## ├─RISK_MM=[24:0x61cb6add33b0] <dbl> 
## └─RainTomorrow=[25:0x61cb72d27690] <fct>

lobstr::ref(ds)

## █ [1:0x61cb7f4cf370] <tibble[,24]> 
## ├─date=[2:0x61cb70942da0] <date> 
## ├─location=[3:0x61cb70477430] <chr> 
## ├─min_temp=[4:0x61cb6e113100] <dbl> 
## ├─max_temp=[5:0x61cb70cc7940] <dbl> 
## ├─rainfall=[6:0x61cb70e82b20] <dbl> 
## ├─evaporation=[7:0x61cb6fa44560] <dbl> 
## ├─sunshine=[8:0x61cb6fbff740] <dbl> 
## ├─wind_gust_dir=[9:0x61cb718fbaa0] <ord> 
## ├─wind_gust_speed=[10:0x61cb6fdba920] <dbl> 
## ├─wind_dir_9am=[11:0x61cb6e2ce2e0] <ord> 
## ├─wind_dir_3pm=[12:0x61cb7103dd00] <ord> 
## ├─wind_speed_9am=[13:0x61cb719f5190] <dbl> 
## ├─wind_speed_3pm=[14:0x61cb71bb0370] <dbl> 
## ├─humidity_9am=[15:0x61cb6f47ab10] <int> 
## ├─humidity_3pm=[16:0x61cb6e52a5d0] <int> 
## ├─pressure_9am=[17:0x61cb71d6b550] <dbl> 
## ├─pressure_3pm=[18:0x61cb71f26730] <dbl> 
## ├─cloud_9am=[19:0x61cb6e925a90] <int> 
## ├─cloud_3pm=[20:0x61cb720e1910] <int> 
## ├─temp_9am=[21:0x61cb721bf220] <dbl> 
## ├─temp_3pm=[22:0x61cb7237a400] <dbl> 
## ├─rain_today=[23:0x61cb725355e0] <fct> 
## ├─risk_mm=[24:0x61cb72612ef0] <dbl> 
## └─rain_tomorrow=[25:0x61cb727ce0d0] <fct>

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