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Creators/Authors contains: "Lee, Rubao"

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  1. The emerging Ray-tracing cores on GPUs have been repurposed for non-ray-tracing tasks by researchers recently. In this paper, we explore the benefits and effectiveness of executing graph algorithms on RT cores. We re-design breadth-first search and triangle counting on the new hardware as graph algorithm representatives. Our implementations focus on how to convert the graph operations to bounding volume hierarchy construction and ray generation, which are computational paradigms specific to ray tracing. We evaluate our RT-based methods on a wide range of real-world datasets. The results do not show the advantage of the RT-based methods over CUDA-based methods. We extend the experiments to the set intersection workload on synthesized datasets, and the RT-based method shows superior performance when the skew ratio is high. By carefully comparing the RT-based and CUDA-based binary search, we discover that RT cores are more efficient at searching for elements, but this comes with a constant and non-trivial overhead of the execution pipeline. Furthermore, the overhead of BVH construction is substantially higher than sorting on CUDA cores for large datasets. Our case studies unveil several rules of adapting graph algorithms to ray-tracing cores that might benefit future evolution of the emerging hardware towards general-computing tasks. 
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    Free, publicly-accessible full text available May 27, 2026
  2. The Ray-Tracing (RT) core has become a widely integrated feature in modern GPUs to accelerate ray-tracing rendering. Recent research has shown that RT cores can also be repurposed to accelerate non-rendering workloads. Since the RT core essentially serves as a hardware accelerator for Bounding Volume Hierarchy (BVH) tree traversal, it holds the potential to significantly improve the performance of spatial workloads. However, the specialized RT programming model poses challenges for using RT cores in these scenarios. Inspired by the core functionality of RT cores, we designed and implemented LibRTS, a spatial index library that leverages RT cores to accelerate spatial queries. LibRTS supports both point and range queries and remains mutable to accommodate changing data. Instead of relying on a case-by-case approach, LibRTS provides a general, highperformance spatial indexing framework for spatial data processing. By formulating spatial queries as RT-suitable problems and overcoming load-balancing challenges, LibRTS delivers superior query performance through RT cores without requiring developers to master complex programming on this specialized hardware. Compared to CPU and GPU spatial libraries, LibRTS achieves speedups of up to 85.1x for point queries, 94.0x for range-contains queries, and 11.0x for range-intersects queries. In a real-world application, pointin-polygon testing, LibRTS also surpasses the state-of-the-art RT method by up to 3.8x. 
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    Free, publicly-accessible full text available February 28, 2026
  3. This guide illuminates the intricate relationship between data management, computer architecture, and system software. It traces the evolution of computing to today's data-centric focus and underscores the importance of hardware-software co-design in achieving efficient data processing systems with high throughput and low latency. The thorough coverage includes topics such as logical data formats, memory architecture, GPU programming, and the innovative use of ray tracing in computational tasks. Special emphasis is placed on minimizing data movement within memory hierarchies and optimizing data storage and retrieval. Tailored for professionals and students in computer science, this book combines theoretical foundations with practical applications, making it an indispensable resource for anyone wanting to master the synergies between data management and computing infrastructure. 
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    Free, publicly-accessible full text available November 21, 2025
  4. We released open-source software Hadoop-GIS in 2011, and presented and published the work in VLDB 2013. This work initiated the development of a new spatial data analytical ecosystem characterized by its large-scale capacity in both computing and data storage, high scalability, compatibility with low-cost commodity processors in clusters and open-source software. After more than a decade of research and development, this ecosystem has matured and is now serving many applications across various fields. In this paper, we provide the background on why we started this project and give an overview of the original Hadoop-GIS software architecture, along with its unique technical contributions and legacy. We present the evolution of the ecosystem and its current state-of-the- art, which has been influenced by the Hadoop-GIS project. We also describe the ongoing efforts to further enhance this ecosystem with hardware accelerations to meet the increasing demands for low latency and high throughput in various spatial data analysis tasks. Finally, we will summarize the insights gained and lessons learned over more than a decade in pursuing high-performance spatial data analytics. 
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  5. We released open-source software Hadoop-GIS in 2011, and presented and published the work in VLDB 2013. This work initiated the development of a new spatial data analytical ecosystem characterized by its large-scale capacity in both computing and data storage, high scalability, compatibility with low-cost commodity processors in clusters and open-source software. After more than a decade of research and development, this ecosystem has matured and is now serving many applications across various fields. In this paper, we provide the background on why we started this project and give an overview of the original Hadoop-GIS software architecture, along with its unique technical contributions and legacy. We present the evolution of the ecosystem and its current state-of the-art, which has been influenced by the Hadoop-GIS project. We also describe the ongoing efforts to further enhance this ecosystem with hardware accelerations to meet the increasing demands for low latency and high throughput in various spatial data analysis tasks. Finally, we will summarize the insights gained and lessons learned over more than a decade in pursuing high-performance spatial data analytics. 
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  6. We released open-source software Hadoop-GIS in 2011, and presented and published the work in VLDB 2013. This work initiated the development of a new spatial data analytical ecosystem characterized by its large-scale capacity in both computing and data storage, high scalability, compatibility with low-cost commodity processors in clusters and open-source software. After more than a decade of research and development, this ecosystem has matured and is now serving many applications across various fields. In this paper, we provide the background on why we started this project and give an overview of the original Hadoop-GIS software architecture, along with its unique technical contributions and legacy. We present the evolution of the ecosystem and its current state-of-the-art, which has been influenced by the Hadoop-GIS project. We also describe the ongoing efforts to further enhance this ecosystem with hardware accelerations to meet the increasing demands for low latency and high throughput in various spatial data analysis tasks. Finally, we will summarize the insights gained and lessons learned over more than a decade in pursuing high-performance spatial data analytics. 
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  7. Fixed-point decimal operations in databases with arbitrary-precision arithmetic refer to the ability to store and operate decimal fraction numbers with an arbitrary length of digits. This type of operation has become a requirement for many applications, including scientific databases, financial data processing, geometric data processing, and cryptography. However, the state-of-the-art fixed-point decimal technology either provides high performance for low-precision operations or supports arbitrary-precision arithmetic operations at low performance. In this paper, we present a design and implementation of a framework called UltraPrecise which supports arbitraryprecision arithmetic for databases on GPU, aiming to gain high performance for arbitrary-precision arithmetic operations. We build our framework based on the just-in-time compilation technique and optimize its performance via data representation design, PTX acceleration, and expression scheduling. UltraPrecise achieves comparable performance to other high-performance databases for low-precision arithmetic operations. For highprecision, we show that UltraPrecise consistently outperforms existing databases by two orders of magnitude, including workloads of RSA encryption and trigonometric function approximation. 
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  8. The tree edit distance (TED) has been found in a wide spectrum of applications in artificial intelligence, bioinformatics, and other areas, which serves as a metric to quantify the dissimilarity between two trees. As applications continue to scale in data size, with a growing demand for fast response time, TED has become even more increasingly data- and computing-intensive. Over the years, researchers have made dedicated efforts to improve sequential TED algorithms by reducing their high complexity. However, achieving efficient parallel TED computation in both algorithm and implementation is challenging due to its dynamic programming nature involving non-trivial issues of data dependency, runtime execution pattern changes, and optimal utilization of limited parallel resources. Having comprehensively investigated the bottlenecks in the existing parallel TED algorithms, we develop a massive parallel computation framework for TED and its implementation on GPU, which is called X-TED. For a given TED computation, X-TED applies a fast preprocessing algorithm to identify dependency relationships among millions of dynamic programming tables. Subsequently, it adopts a dynamic parallel strategy to handle various processing stages, aiming to best utilize GPU cores and the limited device memory in an adaptive and automatic way. Our intensive experimental results demonstrate that X-TED surpasses all existing solutions, achieving up to 42x speedup over the state-of-the-art sequential AP-TED, and outperforming the existing multicore parallel MC-TED by an average speedup of 31x. 
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  9. Indexing is a core technique for accelerating predicate evaluation in databases. After many years of effort, the indexing performance has reached its peak on the existing hardware infrastructure. We propose to use ray tracing (RT) cores to move the indexing performance and efficiency to another level by addressing the following technical challenges: (1) the lack of an efficient mapping of predicate evaluation to a ray tracing job and (2) the poor performance by the heavy and imbalanced ray load when processing skewed datasets. These challenges set obstacles to effectively exploiting RT cores for predicate evaluation. In this paper, we propose RTScan, an approach that leverages RT cores to accelerate index scans. RTScan transforms the evaluation of conjunctive predicates into an efficient ray tracing job in a three-dimensional space. A set of techniques are designed in RTScan, i.e., Uniform Encoding, Data Sieving, and Matrix RT Refine, which significantly enhances the parallelism of scans on RT cores while lightening and balancing the ray load. With the proposed techniques, RTScan achieves high performance for datasets with either uniform or skewed distributions and queries with different selectivities. Extensive evaluations demonstrate that RTScan enhances the scan performance on RT cores by five orders of magnitude and outperforms the state-of-the-art approach on CPU by up to 4.6×. 
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