get better performance [closed]

Question

I have this code that works, but I'm sure that it can be done better, any suggestions?

    Dictionary<string, StrainGroupings> GetOperationStrainGroupings(string locale)
    {
        var result = new Dictionary<string, StrainGroupings>();

        try
        {
            Open();
            setDatabaseTables();
            result = Connection.Table<StrainGroupings>()
                .Where(sg => sg.Locale == locale)
                .Join(Connection.Table<OperationStrainGroups>(), 
                    strainGrouping => strainGrouping.StrainGroupName, 
                    operationStrainGroup => operationStrainGroup.StrainGroupName, 
                    (strainGrouping, operationStrainGroup) => new { Name = operationStrainGroup.OperationName.Distinct(), sg = strainGrouping })
                .AsEnumerable()
                .ToDictionary(row => row.Name.ToString(), row => row.sg);
        }
        catch (Exception ex)
        {
            throw new ApplicationException("Error retrieving operation strain groupings", ex);
        }
        finally { Close(); }
        return result;
    }

It is part of a method that returns a Dictionary(). The idea is return result, as it is dealing with a sQLite Database, it is in a try/catch/finally. That's why I'm not returning result directly, I need to close the database first and maybe dealing with exceptions.