从LINQ到SQL调用UDF和proc的效率如何？

    public IQueryable<DataDTO> GetLotsaData(string dataId, DateTime date, string custIDs)
    {
        var data = (from rs in _context.spXI_GetData(dataId, date, custIDs)
                          select new DataDTO
                          {
                              Time = rs.Time,
                              TimeZone = _context.GetTimezone(postDate, _context.GetDetailedData(rs.PKID, custIDs).FirstOrDefault().Zip),
                              CompletedTime = rs.Completed_Time,
                          });

        return data.AsQueryable<DataDTO>();
    }