  We propose a fast and efficient strategy, called the representative approach,
for big data analysis with generalized linear models, especially for
distributed data with localization requirements or limited network bandwidth.
With a given partition of massive dataset, this approach constructs a
representative data point for each data block and fits the target model using
the representative dataset. In terms of time complexity, it is as fast as the
subsampling approaches in the literature. As for efficiency, its accuracy in
estimating parameters given a homogeneous partition is comparable with the
divide-and-conquer method. Supported by comprehensive simulation studies and
theoretical justifications, we conclude that mean representatives (MR) work
fine for linear models or generalized linear models with a flat inverse link
function and moderate coefficients of continuous predictors. For general cases,
we recommend the proposed score-matching representatives (SMR), which may
improve the accuracy of estimators significantly by matching the score function
values. As an illustrative application to the Airline on-time performance data,
we show that the MR and SMR estimates are as good as the full data estimate
when available.
