Abstract: Data series are stored at multiple resolutions in a computer-readable data storage medium. In particular, time series data values of the data series are received with associated timestamps. Corresponding storage elements in the computer-readable data storage medium are identified based on the time stamps. Aggregate values are determined by summing the time series data values. The time series data values stored in the corresponding storage elements are replaced by the aggregate values. Combined data values of the aggregate values are stored in storage elements in the computer-readable storage medium at a first resolution and second resolution, where the second resolution is half of the first resolution.