Algorithms for Efficient, Compact Online Data Stream Curation
Matthew Andres Moreno, Santiago Rodriguez Papa, Emily Dolson
TL;DR
The paper tackles maintaining a temporally representative, memory-efficient archive of streaming data (stream curation) under read-once, ordered input. It introduces five stateless online policies—Fixed Resolution (FR), Depth-Proportional Resolution (DPR), Recency-Proportional Resolution (RPR), Geometric Sequence nth Root (GSNR), and Curbed Recency-Proportional Resolution (CRPR)—that realize different size-growth and temporal-coverage trade-offs while requiring minimal storage, including $O(1)$ per-update indexing. The authors prove self-consistency for each policy and derive asymptotic space bounds, showing how to achieve both even historical coverage and recency-focused detail, making these methods suitable for low-resource devices. Beyond hereditary stratigraphy, these techniques generalize to sensor networks, data logging, and other memory-constrained data stream mining scenarios, offering practical improvements in efficiency and scalability for online data processing.
Abstract
Data stream algorithms tackle operations on high-volume sequences of read-once data items. Data stream scenarios include inherently real-time systems like sensor networks and financial markets. They also arise in purely-computational scenarios like ordered traversal of big data or long-running iterative simulations. In this work, we develop methods to maintain running archives of stream data that are temporally representative, a task we call "stream curation." Our approach contributes to rich existing literature on data stream binning, which we extend by providing stateless (i.e., non-iterative) curation schemes that enable key optimizations to trim archive storage overhead and streamline processing of incoming observations. We also broaden support to cover new trade-offs between curated archive size and temporal coverage. We present a suite of five stream curation algorithms that span $\mathcal{O}(n)$, $\mathcal{O}(\log n)$, and $\mathcal{O}(1)$ orders of growth for retained data items. Within each order of growth, algorithms are provided to maintain even coverage across history or bias coverage toward more recent time points. More broadly, memory-efficient stream curation can boost the data stream mining capabilities of low-grade hardware in roles such as sensor nodes and data logging devices.
