How to convert DataValues.DataValue to Array? dane_stat.data.values not works

8 core , 8GB RAM, win7 64, fast model, but e.g. : file sav 300 000 KB by
df = load(filename) |> DataFrame
is using in RAM 1.7 GB ! Is normal at this size but in task julia proces growing to 5 GB and using SWAP , if a make rand( 237253,954), task is 3 time lower.

julia> varinfo()
name                    size summary
---------------- ----------- --------------------
Base                         Module
Core                         Module
InteractiveUtils 167.330 KiB Module
Main                         Module
df                 1.737 GiB 237253×954 DataFrame

When I am using ReadStat no this problem, are others : data with missing show small numbers, around epsilon, like there: https://github.com/queryverse/ReadStat.jl/issues/48

Paul