1. A system comprising: one or more processors; one or more computer-readable storage mediums containing instructions configured to cause the one or more processors to perform operations including: deriving, in a single-read pass, multiple structured time series from a distribution of time-stamped unstructured data, wherein the multiple structured time series are in longitudinal form, and wherein the multiple structured time series include a structured time series with a longitudinal dimension associated with a set of attributes; identifying, in the single-read pass, a reduction function from a functions repository; applying, in the single-read pass, the reduction function to the structured time series, wherein applying the reduction function includes mapping data from the longitudinal dimension of the structured time series to data in a coordinate dimension of a time series in coordinate form; identifying, in the single-read pass, a reduced set of attributes from the structured time series using the reduction function, wherein the reduced set of attributes is a subset of attributes extracted from the longitudinal dimension of the structured time series, and wherein the reduced set of attributes includes data that describes the structured time series as a whole; generating, in the single-read pass, a reduced time series using the structured time series and the reduced set of attributes, wherein the reduced time series is in coordinate form, wherein the reduced time series is a subset of the structured time series, and wherein the reduced time series captures the reduced set of attributes; and generating a time series forecast corresponding to the reduced time series.