bluuebunny/crossref_metadata_2025 huggingface dataset:
Language learners’ emotion regulation and enjoyment in an online collaborative writing program
Authors: Zhang Zhipeng , Gao Xuesong (Andy) , Liu Ting , Lee Chwee Beng
Published: September 2022

Collaborative learning in online contexts is emotionally challenging for language learners. To achieve successful learning outcomes, language learners need to regulate their emotions and sustain positive emotions during the collaborative learning process. This study investigated language learners’ emotion regulation and enjoyment, the most extensively researched positive emotion in foreign language learning, in an online collaborative English learning environment. In the study, we collected data by surveying 336 Chinese students majoring in English who collaboratively completed a series of English language writing tasks in 108 online groups facilitated by a social media app (WeChat). Principal component analysis revealed two primary types of emotion regulation: peer regulation and group regulation. The analysis also revealed one factor underpinning enjoyment: enjoyment of online collaboration. Correlation analysis showed medium and positive relationships between peer regulation, group regulation, and enjoyment of online collaboration. Structural equation modeling analysis further found that group regulation exerted a medium-sized direct effect on enjoyment of online collaboration. Peer regulation affected enjoyment of online collaboration moderately and indirectly via group regulation. The theoretical and pedagogical implications of the findings can help to optimize face-to-face and online collaborative language learning activities.
In-page shadowing and two-version timestamp ordering for mobile DBMSs
Authors: Nguyen Lam-Duy , Lee Sang-Won , Nam Beomseok
Published: September 2022

Increasing the concurrency level in mobile database systems has not received much attention, mainly because the concurrency requirements of mobile workloads has been regarded to be low. Contrary to popular belief, mobile workloads require higher concurrency. In this work, we propose novel journaling and concurrency mechanisms for mobile DBMSs, both of which build upon one common concept -
In-Page Shadowing
(IPS). We design and implement a novel In-Page Shadowing recovery method for SQLite to resolve the journaling of journal anomaly, which is known to quadruple the I/O traffic in mobile devices. IPS unions the previous and the next versions of a database page in the same physical page. Using the consolidated two versions of database page, we design
Two-Version Timestamp-Ordering
(2VTO) protocol that enables non-blocking reads as in multi-version concurrency control, but reduces the garbage collection overhead. Designed with mobile environments in mind, IPS and 2VTO are high-performant and resource-efficient transactional solutions. Our performance study shows that IPS and 2VTO outperform state-of-the-art logging methods and an optimistic concurrency control protocol for real mobile workloads.
AcX
Authors: Pereira João L. M. , Casanova João , Galhardas Helena , Shasha Dennis
Published: September 2022

In this information-accumulating world, each of us must learn continuously. To participate in a new field, or even a sub-field, one must be aware of the terminology including the acronyms that specialists know so well, but newcomers do not.

Building on state-of-the art acronym tools, our
end-to-end acronym expander system
called
AcX
takes a document, identifies its acronyms, and suggests expansions that are either found in the document or appropriate given the subject matter of the document. As far as we know, AcX is the first open source and extensible system for acronym expansion that allows mixing and matching of different inference modules. As of now, AcX works for English, French, and Portuguese with other languages in progress.

This paper describes the design and implementation of AcX, proposes
three new acronym expansion benchmarks
, compares state-of-the-art techniques on them, and proposes ensemble techniques that improve on any single technique.

Finally, the paper evaluates the performance of AcX and related work MadDog system in end-to-end experiments on a new human-annotated dataset of Wikipedia documents. Our experiments show that AcX outperforms MadDog but that human performance is still substantially better than the best automated approaches. Thus, achieving Acronym Expansion at a human level is still a rich and open challenge.
NeuChain
Authors: Peng Zeshun , Zhang Yanfeng , Xu Qian , Liu Haixu , Gao Yuxiao , Li Xiaohua , Yu Ge
Published: September 2022

Blockchain serves as a replicated transactional processing system in a trustless distributed environment. Existing blockchain systems all rely on an explicit ordering step to determine the global order of transactions that are collected from multiple peers. The ordering consensus can be the bottleneck since it must be Byzantine-fault tolerant and can scarcely benefit from parallel execution. In this paper, we propose an ordering-free architecture that makes ordering implicit through deterministic execution. Based on this novel architecture, we develop a permissioned blockchain system NeuChain. A number of key optimizations such as asynchronous block generation and pipelining are leveraged for high throughput and low latency. Several security mechanisms are also designed to make our system robust to malicious attacks. Our geo-distributed experimental results show that NeuChain can achieve 47.2--64.1X throughput improvement over HyperLedger Fabric and 1.6--12.2X throughput improvement over the state-of-the-art high performance blockchains.
CARMI
Authors: Zhang Jiaoyi , Gao Yihan
Published: September 2022

Learned indexes, which use machine learning models to replace traditional index structures, have shown promising results in recent studies. However, existing learned indexes exhibit a performance gap between synthetic and real-world datasets, making them far from practical indexes.

In this paper, we identify that ignoring the importance of data partitioning during model training is the main reason for this problem. Thus, we explicitly apply data partitioning to index construction and propose a new efficient and updatable cache-aware RMI framework, called CARMI. Specifically, we introduce entropy as a metric to quantify and characterize the effectiveness of data partitioning of tree nodes in learned indexes and propose a novel cost model, laying a new theoretical foundation for future research. Then, based on our novel cost model, CARMI can automatically determine tree structures and model types under various datasets and workloads by a hybrid construction algorithm without any manual tuning. Furthermore, since memory accesses limit the performance of RMIs, a new cache-aware design is also applied in CARMI, which makes full use of the characteristics of the CPU cache to effectively reduce the number of memory accesses. Our experimental study shows that CARMI performs better than baselines, achieving an average of 2.2X/1.9X speedup compared to B+ Tree/ALEX, while using only about 0.77X memory space of B+ Tree. On the SOSD platform, CARMI outperforms all baselines, with an average speedup of 1.2X over the nearest competitor RMI, which has been carefully tuned for each dataset in advance.
Finding locally densest subgraphs
Authors: Ma Chenhao , Cheng Reynold , Lakshmanan Laks V. S. , Han Xiaolin
Published: September 2022

Finding the densest subgraph (DS) from a graph is a fundamental problem in graph databases. The DS obtained, which reveals closely related entities, has been found to be useful in various application domains such as e-commerce, social science, and biology. However, in a big graph that contains billions of edges, it is desirable to find more than one subgraph cluster that are not necessarily the densest, yet they reveal closely-related vertices. In this paper, we study the locally densest subgraph (LDS), a recently-proposed variant of DS. An LDS is a subgraph which is the densest among the "local neighbors". Given a graph
G
, a number of LDS's can be returned, which reflect different dense regions of
G
and thus give more information than DS. The existing LDS solution suffers from low efficiency. We thus develop a convex-programming-based solution that enables powerful pruning. Extensive experiments on seven real large graph datasets show that our proposed algorithm is up to four orders of magnitude faster than the state-of-the-art.
Query processing on tensor computation runtimes
Authors: He Dong , Nakandala Supun C , Banda Dalitso , Sen Rathijit , Saur Karla , Park Kwanghyun , Curino Carlo , Camacho-Rodríguez Jesús , Karanasos Konstantinos , Interlandi Matteo
Published: September 2022

The huge demand for computation in artificial intelligence (AI) is driving unparalleled investments in hardware and software systems for AI. This leads to an explosion in the number of specialized hardware devices, which are now offered by major cloud vendors. By hiding the low-level complexity through a tensor-based interface, tensor computation runtimes (TCRs) such as PyTorch allow data scientists to efficiently exploit the exciting capabilities offered by the new hardware. In this paper, we explore how database management systems can ride the wave of innovation happening in the AI space.

We design, build, and evaluate Tensor Query Processor (TQP): TQP transforms SQL queries into tensor programs and executes them on TCRs. TQP is able to run the full TPC-H benchmark by implementing novel algorithms for relational operators on the tensor routines. At the same time, TQP can support various hardware while only requiring a fraction of the usual development effort. Experiments show that TQP can improve query execution time by up to 10X over specialized CPU- and GPU-only systems. Finally, TQP can accelerate queries mixing ML predictions and SQL end-to-end, and deliver up to 9X speedup over CPU baselines.
Reliable community search in dynamic networks
Authors: Tang Yifu , Li Jianxin , Haldar Nur Al Hasan , Guan Ziyu , Xu Jiajie , Liu Chengfei
Published: September 2022

Searching for local communities is an important research problem that supports advanced data analysis in various complex networks, such as social networks, collaboration networks, cellular networks, etc. The evolution of such networks over time has motivated several recent studies to identify local communities in dynamic networks. However, these studies only utilize the aggregation of disjoint structural information to measure the quality and ignore the reliability of the communities in a continuous time interval. To fill this research gap, we propose a novel (θ,
k
)-
core
reliable community (CRC) model in the weighted dynamic networks, and define the problem of
most reliable community search
that couples the desirable properties of connection strength, cohesive structure continuity, and the maximal member engagement. To solve this problem, we first develop a novel edge filtering based online CRC search algorithm that can effectively filter out the trivial edge information from the networks while searching for a
reliable
community. Further, we propose an index structure, Weighted Core Forest-Index (WCF-index), and devise an index-based dynamic programming CRC search algorithm, that can prune a large number of insignificant intermediate results and support efficient query processing. Finally, we conduct extensive experiments systematically to demonstrate the efficiency and effectiveness of our proposed algorithms on eight real datasets under various experimental settings.
Cost modelling for optimal data placement in heterogeneous main memory
Authors: Lasch Robert , Legler Thomas , May Norman , Scheirle Bernhard , Sattler Kai-Uwe
Published: September 2022

The cost of DRAM contributes significantly to the operating costs of in-memory database management systems (IMDBMS). Persistent memory (PMEM) is an alternative type of byte-addressable memory that offers --- in addition to persistence --- higher capacities than DRAM at a lower price with the disadvantage of increased latencies and reduced bandwidth. This paper evaluates PMEM as a cheaper alternative to DRAM for storing table base data, which can make up a significant fraction of an IMDBMS' total memory footprint. Using a prototype implementation in the SAP HANA IMDBMS, we find that placing all table data in PMEM can reduce query performance in analytical benchmarks by more than a factor of two, while transactional workloads are less affected. To quantify the performance impact of placing individual data structures in PMEM, we propose a cost model based on a lightweight workload characterization. Using this model, we show how to place data pareto-optimally in the heterogeneous memory. Our evaluation demonstrates the accuracy of the model and shows that it is possible to place more than 75% of table data in PMEM while keeping performance within 10% of the DRAM baseline for two analytical benchmarks.
UPLIFT
Authors: Phani Arnab , Erlbacher Lukas , Boehm Matthias
Published: September 2022

Data science pipelines are typically exploratory. An integral task of such pipelines are feature transformations, which transform raw data into numerical matrices or tensors for training or scoring. There exist a wide variety of transformations for different data modalities. These feature transformations incur large computational overhead due to expensive string processing and dictionary creation. Existing ML systems address this overhead by static parallelization schemes and interleaving transformations with model training. These approaches show good performance improvements for simple transformations, but struggle to handle different data characteristics (many features/distinct items) and multi-pass transformations. A key observation is that good parallelization strategies for feature transformations depend on data characteristics. In this paper, we introduce UPLIFT, a framework forParalleLIzingFeatureTransformations. UPLIFT constructs a fine-grained task graph for a set of transformations, optimizes the plan according to data characteristics, and executes this plan in a cache-conscious manner. We show that the resulting framework is applicable to a wide range of transformations. Furthermore, we propose the FTBench benchmark with transformations and datasets from various domains. On this benchmark, UPLIFT yields speedups of up to 31.6x (9.27x on average) compared to state-of-the-art ML systems.
LlamaTune
Authors: Kanellis Konstantinos , Ding Cong , Kroth Brian , Müller Andreas , Curino Carlo , Venkataraman Shivaram
Published: September 2022

Tuning a database system to achieve optimal performance on a given workload is a long-standing problem in the database community. A number of recent works have leveraged ML-based approaches to guide the sampling of large parameter spaces (hundreds of tuning knobs) in search for high performance configurations. Looking at Microsoft production services operating millions of databases,
sample efficiency emerged as a crucial requirement
to use tuners on diverse workloads.

This motivates our investigation in LlamaTune, a tuner design that leverages domain knowledge to improve the sample efficiency of existing optimizers. LlamaTune employs an automated dimensionality reduction technique based on randomized projections, a biased-sampling approach to handle special values for certain knobs, and knob values bucketization, to reduce the size of the search space. LlamaTune compares favorably with the state-of-the-art optimizers across a diverse set of workloads. It identifies the best performing configurations with up to 11X fewer workload runs, and reaching up to 21% higher throughput. We also show that benefits from LlamaTune generalize across both BO-based and RL-based optimizers, as well as different DBMS versions.

While the journey to perform database tuning at cloud-scale remains long, LlamaTune goes a long way in making automatic DBMS tuning practical at scale.
SCAR
Authors: Hohma Ellen , Frey Christian M. M. , Beer Anna , Seidl Thomas
Published: September 2022

Spectral clustering is one of the most advantageous clustering approaches. However, standard Spectral Clustering is sensitive to noisy input data and has a high runtime complexity. Tackling one of these problems often exacerbates the other. As real-world datasets are often large
and
compromised by noise, we need to improve both robustness and runtime at once. Thus, we propose Spectral Clustering - Accelerated and Robust (SCAR), an accelerated, robustified spectral clustering method. In an iterative approach, we achieve robustness by separating the data into two latent components: cleansed and noisy data. We accelerate the eigendecomposition - the most time-consuming step - based on the Nyström method. We compare SCAR to related recent state-of-the-art algorithms in extensive experiments. SCAR surpasses its competitors in terms of speed and clustering quality on highly noisy data.
Spooky
Authors: Dayan Niv , Weiss Tamar , Dashevsky Shmuel , Pan Michael , Bortnikov Edward , Twitto Moshe
Published: September 2022

Modern storage engines and key-value stores have come to rely on the log-structured merge-tree (LSM-tree) as their core data structure. LSM-tree operates by gradually merge-sorting data across levels of exponentially increasing capacities in storage. A crucial design dimension of LSM-tree is its compaction granularity. Some designs perform
Full Merge
, whereby entire levels get compacted at once. Others perform
Partial Merge
, whereby smaller groups of files with overlapping key ranges are compacted independently. This paper shows that both strategies exhibit serious flaws. With Full Merge, space-amplification is exorbitant. The reason is that while compacting the LSM-tree's largest level, there must be at least twice as much storage space as data to store both the original and new files until the compaction is finished. On the other hand, Partial Merge exhibits excessive write-amplification. The reason is twofold. (1) The files getting compacted typically do not have perfectly overlapping key ranges, and so some non-overlapping data is superfluously rewritten in each compaction. (2) Files with different lifetimes become interspersed within the SSD leading to high SSD garbage-collection overheads. As the data size grows, these problems grow in magnitude.

We introduce Spooky, a novel compaction granulation method to address these problems. Spooky partitions data at the largest level into equally sized files, and it partitions data at smaller levels based on the file boundaries at the largest level. This allows merging one group of perfectly overlapping files at a time to limit space-amplification and compaction overheads. At the same time, Spooky writes larger though fewer files simultaneously so that files with different lifetimes do not become as interspersed within the SSD. This cheapens garbage-collection. We show empirically that Spooky achieves >2x lower space-amplification than Full Merge and >2x lower write-amplification than Partial Merge at the same time.
Identifying similar-bicliques in bipartite graphs
Authors: Yao Kai , Chang Lijun , Yu Jeffrey Xu
Published: September 2022

Bipartite graphs have been widely used to model the relationship between entities of different types, where vertices are partitioned into two disjoint sets/sides. Finding dense subgraphs in a bipartite graph is of great significance and encompasses many applications. However, none of the existing dense bipartite subgraph models consider similarity between vertices from the same side, and as a result, the identified results may include vertices that are not similar to each other. In this paper, we formulate the notion of similar-biclique which is a special kind of biclique where all vertices from a designated side are similar to each other, and aim to enumerate all similar-bicliques. The naive approach of first enumerating all maximal bicliques and then extracting all maximal similar-bicliques from them is inefficient, as enumerating maximal bicliques is time consuming. We propose a backtracking algorithm MSBE to directly enumerate maximal similar-bicliques, and power it by vertex reduction and optimization techniques. Furthermore, we design a novel index structure to speed up a time-critical operation of MSBE, as well as to speed up vertex reduction. Efficient index construction algorithms are also developed. Extensive experiments on 17 bipartite graphs as well as case studies are conducted to demonstrate the effectiveness and efficiency of our model and algorithms.
Towards distribution-aware query answering in data markets
Authors: Asudeh Abolfazl , Nargesian Fatemeh
Published: September 2022

Addressing the increasing demand for data exchange has led to the development of data markets that facilitate transactional interactions between data buyers and data sellers. Still, cost-effective and distribution-aware query answering is a substantial challenge in these environments. In this paper, while differentiating different types of data markets, we take the initial steps towards addressing this challenge. In particular, we envision a unified query answering framework and discuss its functionalities. Our framework enables integrating data from different sources in a data market into a dataset that meets user-provided schema and distribution requirements cost-effectively. In order to facilitate consumers' query answering, our system discovers data views in the form of join-paths on relevant data sources, defines a get-next operation to query views, and estimates the cost of get-next on each view. The query answering engine then selects the next views to sample sequentially to collect the output data. Depending on the knowledge of the system from the underlying data sources, the view selection problem can be modeled as an instance of a multi-arm bandit or coupon collector's problem.
Cardinality estimation of approximate substring queries using deep learning
Authors: Kwon Suyong , Jung Woohwan , Shim Kyuseok
Published: September 2022

Cardinality estimation of an approximate substring query is an important problem in database systems. Traditional approaches build a summary from the text data and estimate the cardinality using the summary with some statistical assumptions. Since deep learning models can learn underlying complex data patterns effectively, they have been successfully applied and shown to outperform traditional methods for cardinality estimations of queries in database systems. However, since they are not yet applied to approximate substring queries, we investigate a deep learning approach for cardinality estimation of such queries. Although the accuracy of deep learning models tends to improve as the train data size increases, producing a large train data is computationally expensive for cardinality estimation of approximate substring queries. Thus, we develop efficient train data generation algorithms by avoiding unnecessary computations and sharing common computations. We also propose a deep learning model as well as a novel learning method to quickly obtain an accurate deep learning-based estimator. Extensive experiments confirm the superiority of our data generation algorithms and deep learning model with the novel learning method.
Data station
Authors: Xia Siyuan , Zhu Zhiru , Zhu Chris , Zhao Jinjin , Chard Kyle , Elmore Aaron J. , Foster Ian , Franklin Michael , Krishnan Sanjay , Fernandez Raul Castro
Published: September 2022

Pooling and sharing data increases and distributes its value. But since data cannot be revoked once shared, scenarios that require controlled release of data for regulatory, privacy, and legal reasons default to not sharing. Because selectively controlling what data to release is difficult, the few data-sharing consortia that exist are often built around data-sharing agreements resulting from long and tedious one-off negotiations.

We introduce Data Station, a data escrow designed to enable the formation of data-sharing consortia. Data
owners
share data with the escrow knowing it will not be released without their consent. Data
users
delegate their computation to the escrow. The data escrow relies on delegated computation to execute queries without releasing the data first. Data Station leverages hardware enclaves to generate
trust
among participants, and exploits the centralization of data and computation to generate an audit log.

We evaluate Data Station on machine learning and data-sharing applications while running on an untrusted intermediary. In addition to important qualitative advantages, we show that Data Station: i) outperforms federated learning baselines in accuracy and runtime for the machine learning application; ii) is orders of magnitude faster than alternative secure data-sharing frameworks; and iii) introduces small overhead on the critical path.
SCARA
Authors: Liao Ningyi , Mo Dingheng , Luo Siqiang , Li Xiang , Yin Pengcheng
Published: September 2022

Recent advances in data processing have stimulated the demand for learning graphs of very large scales. Graph Neural Networks (GNNs), being an emerging and powerful approach in solving graph learning tasks, are known to be difficult to scale up. Most scalable models apply node-based techniques in simplifying the expensive graph message-passing propagation procedure of GNN. However, we find such acceleration insufficient when applied to million- or even billion-scale graphs. In this work, we propose SCARA, a scalable GNN with feature-oriented optimization for graph computation. SCARA efficiently computes graph embedding from node features, and further selects and reuses feature computation results to reduce overhead. Theoretical analysis indicates that our model achieves sub-linear time complexity with a guaranteed precision in propagation process as well as GNN training and inference. We conduct extensive experiments on various datasets to evaluate the efficacy and efficiency of SCARA. Performance comparison with baselines shows that SCARA can reach up to 100x graph propagation acceleration than current state-of-the-art methods with fast convergence and comparable accuracy. Most notably, it is efficient to process precomputation on the largest available billion-scale GNN dataset Papers100M (111M nodes, 1.6B edges) in 100 seconds.
Velox
Authors: Pedreira Pedro , Erling Orri , Basmanova Masha , Wilfong Kevin , Sakka Laith , Pai Krishna , He Wei , Chattopadhyay Biswapesh
Published: September 2022

The ad-hoc development of new specialized computation engines targeted to very specific data workloads has created a siloed data landscape. Commonly, these engines share little to nothing with each other and are hard to maintain, evolve, and optimize, and ultimately provide an inconsistent experience to data users. In order to address these issues, Meta has created Velox, a novel open source C++ database acceleration library. Velox provides reusable, extensible, high-performance, and dialect-agnostic data processing components for building execution engines, and enhancing data management systems. The library heavily relies on vectorization and adaptivity, and is designed from the ground up to support efficient computation over complex data types due to their ubiquity in modern workloads. Velox is currently integrated or being integrated with more than a dozen data systems at Meta, including analytical query engines such as Presto and Spark, stream processing platforms, message buses and data warehouse ingestion infrastructure, machine learning systems for feature engineering and data preprocessing (PyTorch), and more. It provides benefits in terms of (a) efficiency wins by democratizing optimizations previously only found in individual engines, (b) increased consistency for data users, and (c) engineering efficiency by promoting reusability.
OceanBase
Authors: Yang Zhenkun , Yang Chuanhui , Han Fusheng , Zhuang Mingqiang , Yang Bing , Yang Zhifeng , Cheng Xiaojun , Zhao Yuzhong , Shi Wenhui , Xi Huafeng , Yu Huang , Liu Bin , Pan Yi , Yin Boxue , Chen Junquan , Xu Quanqing
Published: September 2022

We have designed and developed OceanBase, a distributed relational database system from the very basics for a decade. Being a scale-out multi-tenant system, OceanBase is cross-region fault tolerant, which is based on the shared-nothing architecture. Besides sharing many similar goals with alternative distributed DBMS, such as horizontal scalability, fault-tolerance, etc., our design has been driven by the demands of typical RDBMS compatibility as well as both on-premise and off-premise deployments. OceanBase has fulfilled its design goal. It implements the salient features of certain mainstream classical RDBMS, and most applications on them can run on OceanBase, with or without a few minor modifications. Tens of thousands of OceanBase servers have been deployed in Alipay.com as well as many other commercial organizations. It has also successfully passed the TPC-C benchmark test and seized the first place with more than 707 million tpmC. This paper presents the goals, design criteria, infrastructure, and key components of OceanBase including its engines for storage and transaction processing. Further, it details how OceanBase achieves the above leading TPC-C benchmark in a distributed cluster with more than 1,500 servers from 3 zones. It also describes lessons what we have learnt in building OceanBase for more than a decade.
VRE
Authors: Lan Hai , Xie Jiong , Bao Zhifeng , Li Feifei , Tian Wei , Wang Fang , Wang Sheng , Zhang Ailin
Published: September 2022

Managing massive trajectory data from various moving objects has always been a demanding task. A desired trajectory data system should be versatile in its supported query types and distance functions, of low storage cost, and be consistently efficient on processing trajectory data of different properties. Unfortunately, none of the existing systems can meet the above three criteria at the same time. To this end, we propose VRE, aversatile,robust, andeconomical trajectory data system.VRE separates the storage from the processing. In the storage layer, we propose a novel segment-based storage model that takes advantage of the strengths of both point-based and trajectory-based storage models. VRE supports these three storage models and ten storage schemas upon them. With the secondary index, VRE reduces the storage cost up to 3x. In the processing layer, we first propose a two-stage processing framework and a pushdown strategy to alleviate full trajectory transmission cost. Then, we design a unified pruning strategy for five widely used trajectory distance functions and numerous tailored processing algorithms for five advanced queries. Extensive experiments are conducted to verify the design choice and efficiency of VRE, from which we present some key insights that are crucial to both VRE and future trajectory system's design.
Beaconnect
Authors: Wingerath Wolfram , Wollmer Benjamin , Bestehorn Markus , Succo Stephan , Ferrlein Sophie , Bücklers Florian , Domnik Jörn , Panse Fabian , Witt Erik , Sener Anil , Gessert Felix , Ritter Norbert
Published: September 2022

Content delivery networks (CDNs) are critical for minimizing access latency in the Web as they efficiently distribute online resources across the globe. But since CDNs can only be enabled on the scope of entire websites (and not for individual users or user groups), the effects of page speed acceleration are often quantified with potentially skewed before-after comparisons rather than statistically sound A/B tests. We introduce the system Beaconnect for collecting and analyzing Web performance data without being subject to these limitations. Our contributions are threefold. First, Beaconnect is natively compatible with A/B testing Web performance as it is built for a custom browser-based acceleration approach and thus does not rely on traditional CDN technology. Second, we present our continuous aggregation pipeline that achieves sub-minute end-to-end latency. Third, we describe and evaluate a scheme for continuous real-time reporting that is especially efficient for large customers and processes data from over 100 million monthly users at Baqend.
Blueprint
Authors: Mishchenko Andrey , Danco Dominique , Jindal Abhilash , Blue Adrian
Published: September 2022

Blueprint is a declarative domain-specific language for document extraction. Users describe document layout using spatial, textual, semantic, and numerical fuzzy constraints, and the language runtime extracts the field-value mappings that best satisfy the constraints in a given document.

We used Blueprint to develop several document extraction solutions in a commercial setting. This approach to the extraction problem proved powerful. Concise Blueprint programs were able to generate good accuracy on a broad set of use cases. However, a major goal of our work was to build a system that non-experts, and in particular non-engineers, could use effectively, and we found that writing declarative fuzzy constraint-based extraction programs was not intuitive for many users: a large up-front learning investment was required to be effective, and debugging was often challenging.

To address these issues, we developed a no-code IDE for Blueprint, called Studio, as well as program synthesis functionality for automatically generating Blueprint programs from training data, which could be created by labeling document samples in our IDE. Overall, the IDE significantly improved the Blueprint development experience and the results users were able to achieve.

In this paper, we discuss the design, implementation, and deployment of Blueprint and Studio. We compare our system with a state-of-the-art deep-learning based extraction tool and show that our system can achieve comparable accuracy results, with comparable development time, for appropriately-chosen use cases, while providing better interpretability and debuggability.
DuckDB-wasm
Authors: Kohn André , Moritz Dominik , Raasveldt Mark , Mühleisen Hannes , Neumann Thomas
Published: September 2022

We introduce DuckDB-Wasm, a WebAssembly version of the database system DuckDB, to provide fast analytical processing for the Web. DuckDB-Wasm evaluates SQL queries asynchronously in web workers, supports efficient user-defined functions written in JavaScript, and features a browser-agnostic filesystem that reads local and remote data in pages. DuckDB-Wasm outperforms previous data processing libraries for the Web in the TPC-H benchmark at multiple scale factors. We demonstrate the capabilities of an analytical database in the browser using an interactive SQL shell.
LIBKDV
Authors: Chan Tsz Nam , Ip Pak Lon , Zhao Kaiyan , U Leong Hou , Choi Byron , Xu Jianliang
Published: September 2022

Kernel density visualization (KDV) has been widely used in many geospatial analysis tasks, including traffic accident hotspot detection, crime hotspot detection, and disease outbreak detection. Although KDV can be supported by many scientific, geographical, and visualization software tools, none of these tools can support high-resolution KDV with large-scale datasets. Therefore, we develop the first versatile programming library, called LIBKDV, based on the set of our complexity-optimized algorithms. Given the high efficiency of these algorithms, LIBKDV not only accelerates the KDV computation but also enriches KDV-based geospatial analytics, including bandwidth-tuning analysis and spatiotemporal analysis, which cannot be natively and feasibly supported by existing software tools. In this demonstration, participants will be invited to use our programming library to explore interesting hotspot patterns on large-scale traffic accident, crime, and COVID-19 datasets.
AutoDI
Authors: Lan Hai , Zhang Yuanjia , Bao Zhifeng , Dong Yu , Huang Dongxu , Tang Liu , Zhang Jian
Published: September 2022

Manual analysis on plan regression is both labor-intensive and inefficient for a large query plan and numerous queries. In this paper, we demonstrate AutoDI, an automatic detection and inference tool that has been developed to investigate why a sub-optimal plan is obtained by analyzing two different plans of the same query. AutoDI consists of two main modules,Difference FinderandInference.The former aims to find where the two plans are different, and the latter tries to obtain the reasons why the differences come out. In our demonstration, we use a real plan regression in TiDB to show how AutoDI works.
VINCENT
Authors: Huang Kai , Ye Qingqing , Zhao Jing , Zhao Xi , Hu Haibo , Zhou Xiaofang
Published: September 2022

Exploratory search is a search paradigm that plays a vital role in databases, data mining, and information retrieval to assist users to get familiar with the underlying databases. It supports iterative query formulation to explore the data space. Despite its growing importance, exploratory search on graph-structured data has not received adequate attention in the literature. In this paper, we demonstrate a novel system called Vincent that facilitates an efficient exploratory subgraph search in a graph database containing a large collection of small or medium-sized graphs. By automatically generating the content for panels in GUI and diversified patterns from databases and providing a visual result explorer, Vincent supports data-driven visual query formulation, incremental subgraph processing, and efficient query result summarization.
Sigma workbook
Authors: Gale James , Seiden Max , Utkarsh Deepanshu , Frantz Jason , Woollen Rob , Demiralp Çağatay
Published: September 2022

Cloud data warehouses (CDWs) bring large-scale data and compute power closer to users in enterprises. However, existing tools for analyzing data in CDWs are either limited in ad-hoc transformations or difficult to use for business users. Here we introduce Sigma Workbook, a new interactive system that enables business users to easily perform visual analysis of data in CDWs at scale. For this, Sigma Workbook provides an accessible spreadsheet-like interface for analysis through direct manipulation. Sigma Workbook dynamically constructs matching SQL queries from user interactions, building on the versatility and expressivity of SQL. Constructed queries are directly executed on CDWs, leveraging the superior characteristics of the new generation CDWs, including scalability. We demonstrate Sigma Workbook through 3 real-life use cases---cohort analysis, sessionization, and data augmentation---and underline Workbook's ease of use, scalability, and expressivity.
ReMac
Authors: Chen Zihao , Xu Zhizhen , Han Baokun , Xu Chen , Qian Weining , Zhou Aoying
Published: September 2022

Distributed matrix computation solutions support query interfaces of linear algebra expressions, which often contain redundancy, i.e., common and loop-constant subexpressions. However, existing solutions fail to find all redundant subexpressions. Moreover, eliminating the found redundancy leads to new execution order of operators, which may have side effect. To exploit the benefits of redundancy elimination, we propose a new system called
ReMac
, which performs
automatic
and
adaptive elimination.
In particular, automatic elimination adopts a block-wise search that exploits the properties of matrix computation for speed-up. Adaptive elimination employs a cost model and a dynamic programming-based method to generate efficient plans with redundancy elimination. In this demonstration, attendees will have an opportunity to experience the effect that automatic and adaptive elimination have on distributed matrix computation.
Pipemizer
Authors: Gakhar Sunny , Cahoon Joyce , Le Wangchao , Li Xiangnan , Ravichandran Kaushik , Patel Hiren , Friedman Marc , Haynes Brandon , Qiao Shi , Jindal Alekh , Leeka Jyoti
Published: September 2022

We demonstrate
Pipemizer
, an optimizer and recommender aimed at improving the performance of queries or jobs in pipelines. These job pipelines are ubiquitous in modern data analytics due to jobs reading output files written by other jobs. Given that more than 650k jobs run on Microsoft's SCOPE job service per day and about 70% have inter-job dependencies, identifying optimization opportunities across query jobs is of considerable interest to both cluster operators and users.
Pipemizer
addresses this need by providing recommendations to users, allowing users to understand their system, and facilitating automated application of recommendations.
Pipemizer
introduces novel optimizations that include holistic pipeline-aware statistics generation, inter-job operator push-up, and job split & merge. This demonstration showcases optimizations and recommendations generated by
Pipemizer
, enabling users to understand and optimize job pipelines.
WebMILE
Authors: He Yuntian , Zhang Yue , Gurukar Saket , Parthasarathy Srinivasan
Published: September 2022

In recent years, we have seen the success of network representation learning (NRL) methods in diverse domains ranging from computational chemistry to drug discovery and from social network analysis to bioinformatics algorithms. However, each such NRL method is typically prototyped in a programming environment familiar to the developer. Moreover, such methods rarely scale out to large-scale networks or graphs. Such restrictions are problematic to domain scientists or end-users who want to scale a particular NRL method-of-interest on large graphs from their specific domain.

In this work, we present a novel system, WebMILE to democratize this process. WebMILE can scale an unsupervised network embedding method written in the user's preferred programming language on large graphs. It provides an easy-to-use Graphical User Interface (GUI) for the end-user. The user provides the necessary input (embedding method file, graph, required packages information) through a simple GUI, and WebMILE executes the input network embedding method on the given input graph. WebMILE leverages a pioneering multi-level method, MILE (alternatively DistMILE if the user has access to a cluster), that can scale a network embedding method on large graphs. The language agnosticity is achieved through a simple Docker interface. In this demonstration, we will showcase how a domain scientist or end-user can utilize WebMILE to rapidly prototype and learn node embeddings of a large graph in a flexible and efficient manner - ensuring the twin goals of high productivity and high performance.
Demonstrating quest
Authors: Geisler Nadja , Hättasch Benjamin , Binnig Carsten
Published: September 2022

Machine learning models are everywhere now; but only few of them are transparent in how they work. To remedy this, local explanations aim to show users how and why learned models produce a certain output for a given input (data sample). However, most existing approaches are oriented around images or text data and, thus, cannot leverage the structure and properties of tabular data. Therefore, we demonstrate Quest, a new framework for generating explanations that are a better fit for tabular data. The main idea is to create explanations in the form of relational predicates (called queries hereafter) that approximate the behavior of a classifier around the given sample. For this demo, we use Quest on different synthetic and real-world tabular data sets and pair it with a user interface intended to be used during model development by a data scientist working on classification models.
IsoBugView
Authors: Ripberger Drew , Gan Yifan , Ren Xueyuan , Blanas Spyros , Wang Yang
Published: September 2022

Database applications frequently use weaker isolation levels, such as Read Committed, for better performance, which may lead to bugs that do not happen under Serializable. Although a number of works have proposed methods to identify such isolation-related bugs, the difficulty of analyzing reported bugs is often underestimated, since these bugs often involve multiple complicated transactions interleaved in a specific order and they often require users' feedback to improve the accuracy of bug analysis.

This paper presents IsoBugView, a tool to visualize isolation bugs and incorporate users' feedback: to address the challenge that a complicated bug may include much information and thus is hard to present, IsoBugView displays a high-level overview of the bug first and displays further information of individual pieces if the developer needs further investigation. To incorporate users' feedback, IsoBugView embeds hook functions into the backend analysis tool to preprocess a dependency graph and postprocess a found cycle and further allows a user to apply predefined hook functions in its graphic user interface. Our experience shows that IsoBugView has greatly improved our productivity of analyzing isolation bugs.
Demonstration of accelerating machine learning inference queries with correlative proxy models
Authors: Yang Zhihui , Huang Yicong , Wang Zuozhi , Gao Feng , Lu Yao , Li Chen , Wang X. Sean
Published: September 2022

We will demonstrate a prototype query-processing engine, which utilizes correlations among predicates to accelerate machine learning (ML) inference queries on unstructured data. Expensive operators such as feature extractors and classifiers are deployed as user-defined functions (UDFs), which are not penetrable by classic query optimization techniques such as predicate push-down. Recent optimization schemes (e.g., Probabilistic Predicates or PP) build a cheap proxy model for each predicate offline, and inject proxy models in the front of expensive ML UDFs under the independence assumption in queries. Input records that do not satisfy query predicates are filtered early by proxy models to bypass ML UDFs. But enforcing the independence assumption may result in sub-optimal plans. We use correlative proxy models to better exploit predicate correlations and accelerate ML queries. We will demonstrate our query optimizer called CORE, which builds proxy models online, allocates parameters to each model, and reorders them. We will also show end-to-end query processing with or without proxy models.
Demonstration of collaborative and interactive workflow-based data analytics in texera
Authors: Liu Xiaozhen , Wang Zuozhi , Ni Shengquan , Alsudais Sadeem , Huang Yicong , Kumar Avinash , Li Chen
Published: September 2022

Collaborative data analytics is becoming increasingly important due to the higher complexity of data science, more diverse skills from different disciplines, more common asynchronous schedules of team members, and the global trend of working remotely. In this demo we will show how Texera supports this emerging computing paradigm to achieve high productivity among collaborators with various backgrounds. Based on our active joint projects on the system, we use a scenario of social media analysis to show how a data science task can be conducted on a user friendly yet powerful platform by a multi-disciplinary team including domain scientists with limited coding skills and experienced machine learning experts. We will present how to do collaborative editing of a workflow and collaborative execution of the workflow in Texera. We will focus on data-centric features such as synchronization of operator schemas among the users during the construction phase, and monitoring and controlling the shared runtime during the execution phase.
Transformers for tabular data representation
Authors: Badaro Gilbert , Papotti Paolo
Published: September 2022

In the last few years, the natural language processing community witnessed advances in neural representations of free texts with transformer-based language models (LMs). Given the importance of knowledge available in relational tables, recent research efforts extend LMs by developing neural representations for tabular data. In this tutorial, we present these proposals with two main goals. First, we introduce to a database audience the potentials and the limitations of current models. Second, we demonstrate the large variety of data applications that benefit from the transformer architecture. The tutorial aims at encouraging database researchers to engage and contribute to this new direction, and at empowering practitioners with a new set of tools for applications involving text and tabular data.