How to implement SQL Groupby in RAPIDS












1















I'm seeking to translate an SQL query to use RAPIDS. Consider the simplified query below:



(SELECT min(a), max(b), c
FROM T
GROUP BY c) AS result


I have validated the code below, but is this the optimal solution? Is sorting on the group key necessary? Is there a cleaner / more idiomatic way to write it?



from pygdf import DataFrame as gdf

T = gdf(...)
df = gdf({'a':T.a, 'c':T.c}).groupby('c').min().sort_values(by='c')
df['max_b'] = gdf({'b':T.b, 'c':T.c}).groupby('c').max().sort_values(by='c').max_b
result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})









share|improve this question





























    1















    I'm seeking to translate an SQL query to use RAPIDS. Consider the simplified query below:



    (SELECT min(a), max(b), c
    FROM T
    GROUP BY c) AS result


    I have validated the code below, but is this the optimal solution? Is sorting on the group key necessary? Is there a cleaner / more idiomatic way to write it?



    from pygdf import DataFrame as gdf

    T = gdf(...)
    df = gdf({'a':T.a, 'c':T.c}).groupby('c').min().sort_values(by='c')
    df['max_b'] = gdf({'b':T.b, 'c':T.c}).groupby('c').max().sort_values(by='c').max_b
    result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})









    share|improve this question



























      1












      1








      1








      I'm seeking to translate an SQL query to use RAPIDS. Consider the simplified query below:



      (SELECT min(a), max(b), c
      FROM T
      GROUP BY c) AS result


      I have validated the code below, but is this the optimal solution? Is sorting on the group key necessary? Is there a cleaner / more idiomatic way to write it?



      from pygdf import DataFrame as gdf

      T = gdf(...)
      df = gdf({'a':T.a, 'c':T.c}).groupby('c').min().sort_values(by='c')
      df['max_b'] = gdf({'b':T.b, 'c':T.c}).groupby('c').max().sort_values(by='c').max_b
      result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})









      share|improve this question
















      I'm seeking to translate an SQL query to use RAPIDS. Consider the simplified query below:



      (SELECT min(a), max(b), c
      FROM T
      GROUP BY c) AS result


      I have validated the code below, but is this the optimal solution? Is sorting on the group key necessary? Is there a cleaner / more idiomatic way to write it?



      from pygdf import DataFrame as gdf

      T = gdf(...)
      df = gdf({'a':T.a, 'c':T.c}).groupby('c').min().sort_values(by='c')
      df['max_b'] = gdf({'b':T.b, 'c':T.c}).groupby('c').max().sort_values(by='c').max_b
      result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})






      python rapids






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      edited Nov 20 '18 at 16:59







      Thomas Ryan Stovall

















      asked Nov 20 '18 at 16:49









      Thomas Ryan StovallThomas Ryan Stovall

      405




      405
























          1 Answer
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          You can rewrite your aggregation using the .agg function to make it more straightforward:



          from pygdf import DataFrame as gdf

          T = gdf(...)
          df = gdf({'a':T.a, 'b': T.b, 'c':T.c}).groupby('c').agg({'a': 'min', 'b': 'max'})
          result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})





          share|improve this answer























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            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2














            You can rewrite your aggregation using the .agg function to make it more straightforward:



            from pygdf import DataFrame as gdf

            T = gdf(...)
            df = gdf({'a':T.a, 'b': T.b, 'c':T.c}).groupby('c').agg({'a': 'min', 'b': 'max'})
            result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})





            share|improve this answer




























              2














              You can rewrite your aggregation using the .agg function to make it more straightforward:



              from pygdf import DataFrame as gdf

              T = gdf(...)
              df = gdf({'a':T.a, 'b': T.b, 'c':T.c}).groupby('c').agg({'a': 'min', 'b': 'max'})
              result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})





              share|improve this answer


























                2












                2








                2







                You can rewrite your aggregation using the .agg function to make it more straightforward:



                from pygdf import DataFrame as gdf

                T = gdf(...)
                df = gdf({'a':T.a, 'b': T.b, 'c':T.c}).groupby('c').agg({'a': 'min', 'b': 'max'})
                result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})





                share|improve this answer













                You can rewrite your aggregation using the .agg function to make it more straightforward:



                from pygdf import DataFrame as gdf

                T = gdf(...)
                df = gdf({'a':T.a, 'b': T.b, 'c':T.c}).groupby('c').agg({'a': 'min', 'b': 'max'})
                result = gdf({'a': df.min_a, 'b': df.max_b, 'c':df.c})






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 23 '18 at 20:35









                Keith KrausKeith Kraus

                361




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