U-SQL

@searchlog =
    EXTRACT UserId          int,
            Start           DateTime,
            Region          string,
            Query           string,
            Duration        int,
            Urls            string,
            ClickedUrls     string
    FROM "/Samples/Data/SearchLog.tsv"
    USING Extractors.Tsv();

@result =
    SELECT Region,
           COUNT(*) AS Count
    FROM @searchlog
    GROUP BY Region;

OUTPUT @result
TO "/Output/SearchLog-Region-Count.csv"
USING Outputters.Csv();