EDBT 2026 Demo / reviewers in the wild / expert
Sandeep Tata
dblp:20/1055
· DBLP profile ↗
32ranked-venue papers in the field
9as first author
7since 2021 · last 2024
0009-0007-7785-5516ORCID · corroborated
Domains — venue-derived; a paper can count in several
Database Systems & Data Management · 21 (8 first)Data Mining & Knowledge Discovery · 9 (1 first)Information Retrieval & Web Search · 2
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2024 | FieldSwap: Data Augmentation for Effective Form-Like Document ExtractionabstractExtracting structured data from visually rich documents like invoices, receipts, financial statements, and tax forms is key to automating many business workflows. However, building extraction models in this domain often demands a large collection of high-quality training examples. To address this challenge, we introduce FieldSwap, a novel data augmentation technique specifically designed for such extraction problems. FieldSwap generates synthetic training examples by replacing key phrases indicative of one field with those corresponding to another. Our experiments on five diverse datasets demonstrate that incorporating FieldSwap-augmented data into the training process can enhance model performance by 1–11 F1 points, particularly when dealing with limited training data (10–100 documents). Additionally, we propose algorithms for automatically inferring key phrases from the training data. Our findings indicate that FieldSwap is effective regardless of whether key phrases are manually provided by human experts or inferred automatically. Jing Xie 0002, James B. Wendt, Yichao Zhou 0001, Seth Ebner, Sandeep Tata |
ICDE | 5 |
| 2024 | Measuring an LLM's Proficiency at using APIs: A Query Generation StrategyabstractConnecting Large Language Models (LLMs) with the ability to leverage APIs (Web Search, Charting, Calculators, Calendar, Flight Search, Hotel Search, Data Lookup, etc. ) is likely to allow us to solve a variety of new hard problems.Several research efforts have made this observation and suggested recipes for LLMs to emit API calls, and proposed mechanisms by which they can generate additional text conditioned on the output for the API call.However, in practice, the focus has been on relatively simple slot-filling tasks that make an API call rather unlocking novel capabilities by combining different tools, reasoning over the response from a tool, making multiple invocations, or complex planning.In this paper, we pose the following question: what does it mean to say that an LLM is proficient at using a set of APIs?We answer this question in the context of structured APIs by defining seven capabilities for API-use.We provide an approach for generating synthetic tasks that exercise each of these capabilities given only the description of an API 1 .We argue that this provides practitioners with a principled way to construct a dataset to evaluate an LLM's ability to use a given set of APIs.Through human evaluations, we show that our approach produces high-quality tasks for each of the seven capabilities.We also describe how we used this approach to on-board new API and create principled evaluation sets for multiple LLM-based products. Ying Sheng 0002, Sudeep Gandhe, Bhargav Kanagal, Nicholas Gerard Edmonds, Zachary Fisher, Sandeep Tata, Aarush Selvan |
KDD | 6 |
| 2023 | VRDU: A Benchmark for Visually-rich Document UnderstandingabstractUnderstanding visually-rich business documents to extract structured data and automate business workflows has been receiving attention both in academia and industry. Although recent multi-modal language models have achieved impressive results, we find that existing benchmarks do not reflect the complexity of real documents seen in industry. In this work, we identify the desiderata for a more comprehensive benchmark and propose one we call Visually Rich Document Understanding (VRDU). VRDU contains two datasets that represent several challenges: rich schema including diverse data types as well as hierarchical entities, complex templates including tables and multi-column layouts, and diversity of different layouts (templates) within a single document type. We design few-shot and conventional experiment settings along with a carefully designed matching algorithm to evaluate extraction results. We report the performance of strong baselines and offer three observations: (1) generalizing to new document templates is still very challenging, (2) few-shot performance has a lot of headroom, and (3) models struggle with hierarchical fields such as line-items in an invoice. We plan to open source the benchmark and the evaluation toolkit. We hope this helps the community make progress on these challenging tasks in extracting structured data from visually rich documents. Zilong Wang 0002, Yichao Zhou 0001, Wei Wei 0019, Chen-Yu Lee, Sandeep Tata |
KDD | 5 |
| 2022 | DI-2022: The Third Document Intelligence WorkshopabstractBusiness documents are central to the operation of all organizations, and they come in all shapes and sizes: project reports, planning documents, technical specifications, financial statements, meeting minutes, legal agreements, contracts, resumes, purchase orders, invoices, and many more. The ability to read, understand and interpret these documents, referred to here as Document Intelligence (DI), is challenging due to not only many domains of knowledge involved, but also their complex formats and structures, internal and external cross references deployed, and even less-than-ideal quality of scans and OCR oftentimes performed on them. This workshop aims to explore and advance the current state of research and practice in answering these challenges. Ani Nenkova, Douglas Burdick, Benjamin Han, Dave Lewis 0003, Sandeep Tata, Dan Tecuci |
KDD | 5 |
| 2022 | Learning Transferable Node Representations for Attribute Extraction from Web DocumentsabstractGiven a web page, extracting an object along with various attributes of interest (e.g. price, publisher, author, and genre for a book) can facilitate a variety of downstream applications such as large-scale knowledge base construction, e-commerce product search, and personalized recommendation. Prior approaches have either relied on computationally expensive visual feature engineering or required large amounts of training data to get to an acceptable precision. In this paper, we propose a novel method, LeArNing TransfErable node RepresentatioNs for Attribute Extraction (LANTERN), to tackle the problem. We model the problem as a tree node tagging task. The key insight is to learn a contextual representation for each node in the DOM tree where the context explicitly takes into account the tree structure of the neighborhood around the node. Experiments on the SWDE public dataset show that LANTERN outperforms the previous state-of-the-art (SOTA) by 1.44% (F1 score) with a dramatically simpler model architecture. Furthermore, we report that utilizing data from a different domain (for instance, using training data about web pages with cars to extract book objects) is surprisingly useful and helps beat the SOTA by a further 1.37%. Yichao Zhou 0001, Ying Sheng 0002, Nguyen Vo, Nicholas Gerard Edmonds, Sandeep Tata |
WSDM | 5 |
| 2021 | DI-2021: The Second Document Intelligence WorkshopabstractBusiness documents are central to the operation of all organizations, and they come in all shapes and sizes: project reports, planning documents, technical specifications, financial statements, meeting minutes, legal agreements, contracts, resumes, purchase orders, invoices, and many more. The ability to read, understand and interpret these documents, referred to here as Document Intelligence (DI), is challenging due to not only many domains of knowledge involved, but also their complex formats and structures, internal and external cross references deployed, and even less-than-ideal quality of scans and OCR oftentimes performed on them. This workshop aims to explore and advance the current state of research and practice in answering these challenges. Benjamin Han, Douglas Burdick, Dave Lewis 0003, Yijuan Lu, Hamid R. Motahari Nezhad, Sandeep Tata |
KDD | 6 |
| 2021 | Glean: Structured Extractions from Templatic DocumentsabstractExtracting structured information from templatic documents is an important problem with the potential to automate many real-world business workflows such as payment, procurement, and payroll. The core challenge is that such documents can be laid out in virtually infinitely different ways. A good solution to this problem is one that generalizes well not only to known templates such as invoices from a known vendor, but also to unseen ones. We developed a system called Glean to tackle this problem. Given a target schema for a document type and some labeled documents of that type, Glean uses machine learning to automatically extract structured information from other documents of that type. In this paper, we describe the overall architecture of Glean, and discuss three key data management challenges : 1) managing the quality of ground truth data, 2) generating training data for the machine learning model using labeled documents, and 3) building tools that help a developer rapidly build and improve a model for a given document type. Through empirical studies on a real-world dataset, we show that these data management techniques allow us to train a model that is over 5 F1 points better than the exact same model architecture without the techniques we describe. We argue that for such information-extraction problems, designing abstractions that carefully manage the training data is at least as important as choosing a good model architecture. Sandeep Tata, Navneet Potti, James B. Wendt, Lauro Beltrão Costa, Marc Najork, Beliz Gunel |
Proc. VLDB Endow. | 1 |
| 2020 | Migrating a Privacy-Safe Information Extraction System to a Software 2.0 Design
Ying Sheng 0002, Nguyen Vo, James B. Wendt, Sandeep Tata, Marc Najork |
CIDR | 4 |
| 2020 | Improving Recommendation Quality in Google DriveabstractQuick Access is a machine-learned system in Google Drive that predicts which files a user wants to open. Adding Quick Access recommendations to the Drive homepage cut the amount of time that users spend locating their files in half. Aggregated over the ~1 billion users of Drive, the time saved up adds up to ~1000 work weeks every day. In this paper, we discuss both the challenges of iteratively improving the quality of a personal recommendation system as well as the variety of approaches that we took in order to improve this feature. We explored different deep network architectures, novel modeling techniques, additional data sources, and the effects of latency and biases in the UX. We share both pitfalls as well as successes in our attempts to improve this product, and also discuss how we scaled and managed the complexity of the system. We believe that these insights will be especially useful to those who are working with private corpora as well as those who are building a large-scale production recommendation system. Suming J. Chen, Zhen Qin 0001, Zac Wilson, Brian Calaci, Ryan Evans, Sean Abraham, Donald Metzler, Sandeep Tata, Mike Colagrosso |
KDD | 9 |
| 2020 | FreeDOM: A Transferable Neural Architecture for Structured Information Extraction on Web DocumentsabstractExtracting structured data from HTML documents is a long-studied problem with a broad range of applications like augmenting knowledge bases, supporting faceted search, and providing domain-specific experiences for key verticals like shopping and movies. Previous approaches have either required a small number of examples for each target site or relied on carefully handcrafted heuristics built over visual renderings of websites. In this paper, we present a novel two-stage neural approach, named FreeDOM, which overcomes both these limitations. The first stage learns a representation for each DOM node in the page by combining both the text and markup information. The second stage captures longer range distance and semantic relatedness using a relational neural network. By combining these stages, FreeDOM is able to generalize to unseen sites after training on a small number of seed sites from that vertical without requiring expensive hand-crafted features over visual renderings of the page. Through experiments on a public dataset with 8 different verticals, we show that FreeDOM beats the previous state of the art by nearly 3.7 F1 points on average without requiring features over rendered pages or expensive hand-crafted features. Bill Y. Lin, Ying Sheng 0002, Nguyen Vo, Sandeep Tata |
KDD | 4 |
| 2019 | ItemSuggest: A Data Management Platform for Machine Learned Ranking Services
Sandeep Tata, Vlad Panait, Suming J. Chen, Mike Colagrosso |
CIDR | 1 |
| 2019 | RiSER: Learning Better Representations for Richly Structured EmailsabstractRecent studies show that an overwhelming majority of emails are machine-generated and sent by businesses to consumers. Many large email services are interested in extracting structured data from such emails to enable intelligent assistants. This allows experiences like being able to answer questions such as “What is the address of my hotel in New York?” or “When does my flight leave?”. A high-quality email classifier is a critical piece in such a system. In this paper, we argue that the rich formatting used in business-to-consumer emails contains valuable information that can be used to learn better representations. Most existing methods focus only on textual content and ignore the rich HTML structure of emails. We introduce RiSER (Richly Structured Email Representation) - an approach for incorporating both the structure and content of emails. RiSER projects the email into a vector representation by jointly encoding the HTML structure and the words in the email. We then use this representation to train a classifier. To our knowledge, this is the first description of a neural technique for combining formatting information along with the content to learn improved representations for richly formatted emails. Experimenting with a large corpus of emails received by users of Gmail, we show that RiSER outperforms strong attention-based LSTM baselines. We expect that these benefits will extend to other corpora with richly formatted documents. We also demonstrate with examples where leveraging HTML structure leads to better predictions. Furkan Kocayusufoglu, Ying Sheng 0002, Nguyen Vo, James B. Wendt, Sandeep Tata, Marc Najork |
WWW | 6 |
| 2019 | Online Template Induction for Machine-Generated EmailsabstractIn emails, information abounds. Whether it be a bill reminder, a hotel confirmation, or a shipping notification, our emails contain useful bits of information that enable a number of applications. Most of this email traffic is machine-generated, sent from a business to a human. These business-to-consumer emails are typically instantiated from a set of email templates, and discovering these templates is a key step in enabling a variety of intelligent experiences. Existing email information extraction systems typically separate information extraction into two steps: an offline template discovery process (called template induction) that is periodically run on a sample of emails, and an online email annotation process that applies discovered templates to emails as they arrive. Since information extraction requires an email's template to be known, any delay in discovering a newly created template causes missed extractions, lowering the overall extraction coverage. In this paper, we present a novel system called Crusher that discovers templates completely online, reducing template discovery delay from a week (for the existing MapReduce-based batch system) to minutes. Furthermore, Crusher has a resource consumption footprint that is significantly smaller than the existing batch system. We also report on the surprising lesson we learned that conventional stream processing systems do not present a good framework on which to build Crusher. Crusher delivers an order of magnitude more throughput than a prototype built using a stream processing engine. We hope that these lessons help designers of stream processing systems accommodate a broader range of applications like online template induction in the future. Michael J. Whittaker, Nicholas Gerard Edmonds, Sandeep Tata, James B. Wendt, Marc Najork |
Proc. VLDB Endow. | 3 |
| 2018 | Recommendations for All: Solving Thousands of Recommendation Problems DailyabstractRecommender systems are a key technology for many online services including e-commerce, movies, music, and news. Online retailers use product recommender systems to help users discover items that they may like. However, building a large-scale product recommender system is a challenging task. The problems of sparsity and cold-start are much more pronounced in this domain. Large online retailers have used good recommendations to drive user engagement and improve revenue, but the complexity involved is a roadblock to widespread adoption by smaller retailers. In this paper, we tackle the problem of generating product recommendations for tens of thousands of online retailers. Sigmund is an industrial-scale system for providing recommendations as a service. Sigmund was deployed to production in early 2014 and has been serving retailers every day. We describe the design choices that we made in order to train accurate matrix factorization models at minimal cost. We also share the lessons we learned from this experience - both from a machine learning perspective and a systems perspective. We hope that these lessons are useful for building future machine-learning services. Bhargav Kanagal, Sandeep Tata |
ICDE | 2 |
| 2018 | Anatomy of a Privacy-Safe Large-Scale Information Extraction System Over EmailabstractExtracting structured data from emails can enable several assistive experiences, such as reminding the user when a bill payment is due, answering queries about the departure time of a booked flight, or proactively surfacing an emailed discount coupon while the user is at that store. This paper presents Juicer, a system for extracting information from email that is serving over a billion Gmail users daily. We describe how the design of the system was informed by three key principles: scaling to a planet-wide email service, isolating the complexity to provide a simple experience for the developer, and safeguarding the privacy of users (our team and the developers we support are not allowed to view any single email). We describe the design tradeoffs made in building this system, the challenges faced and the approaches used to tackle them. We present case studies of three extraction tasks implemented on this platform---bill reminders, commercial offers, and hotel reservations---to illustrate the effectiveness of the platform despite challenges unique to each task. Finally, we outline several areas of ongoing research in large-scale machine-learned information extraction from email. Ying Sheng 0002, Sandeep Tata, James B. Wendt, Jing Xie 0002, Marc Najork |
KDD | 2 |
| 2018 | Hidden in Plain Sight: Classifying Emails Using Embedded Image ContentsabstractA vast majority of the emails received by people today are machine-generated by businesses communicating with consumers. While some emails originate as a result of a transaction (e.g., hotel or restaurant reservation confirmations, online purchase receipts, shipping notifications, etc.), a large fraction are commercial emails promoting an offer (a special sale, free shipping, available for a limited time, etc.). The sheer number of these promotional emails makes it difficult for users to read all these emails and decide which ones are actually interesting and actionable. In this paper, we tackle the problem of extracting information from commercial emails promoting an offer to the user. This information enables an email platform to build several new experiences that can unlock the value in these emails without the user having to navigate and read all of them. For instance, we can highlight offers that are expiring soon, or display a notification when there»s an unexpired offer from a merchant if your phone recognizes that you are at that merchant»s store. A key challenge in extracting information from such commercial emails is that they are often image-rich and contain very little text. Training a machine learning (ML) model on a rendered image-rich email and applying it to each incoming email can be prohibitively expensive. In this paper, we describe a cost-effective approach for extracting signals from both the text and image content of commercial emails in the context of Gmail, an email platform that serves over a billion users around the world. The key insight is to leverage the template structure of emails, and use off-the-shelf OCR techniques to obtain the text from images to augment the existing text features offline. Compared to a text-only approach, we show that we are able to identify 9.12% more email templates corresponding to ~5% more emails being identified as offers. Interestingly, our analysis shows that this 5% improvement in coverage is across the board, irrespective of whether the emails were sent by large merchants or small local merchants, allowing us to deliver an improved experience for everyone. Navneet Potti, James B. Wendt, Sandeep Tata, Marc Najork |
WWW | 4 |
| 2017 | Quick Access: Building a Smart Experience for Google DriveabstractGoogle Drive is a cloud storage and collaboration service used by hundreds of millions of users around the world. Quick Access is a new feature in Google Drive that surfaces the most relevant documents when a user visits the home screen. Our metrics show that users locate their documents in half the time with this feature compared to previous approaches. The development of Quick Access illustrates many general challenges and constraints associated with practical machine learning such as protecting user privacy, working with data services that are not designed with machine learning in mind, and evolving product definitions. We believe that the lessons learned from this experience will be useful to practitioners tackling a wide range of applied machine learning problems. Sandeep Tata, Alexandrin Popescul, Marc Najork, Mike Colagrosso, Julian Gibbons, Alan Green, Alexandre Mah, Michael Smith 0024, Divanshu Garg, Cayden Meyer, Reuben Kan |
KDD | 1 |
| 2014 | Diff-Index: Differentiated Index in Distributed Log-Structured Data StoresabstractLog-Structured-Merge (LSM) Tree gains much attention re-cently because of its superior performance in write-intensive workloads. LSM Tree uses an append-only structure in memory to achieve low write latency; at memory capac-ity, in-memory data are flushed to other storage media (e.g. disk). Consequently, read access is slower comparing to write. These specific features of LSM, including no in-place update and asymmetric read/write performance raise unique challenges in index maintenance for LSM. The structural difference between LSM and B-Tree also prevents mature B-Tree based approaches from being directly applied. To address the issues of index maintenance for LSM, we pro-pose Diff-Index to support a spectrum of index maintenance schemes to suit different objectives in index consistency and performance. The schemes consist of sync-full, sync-insert, async-simple and async-session. Experiments on our HBase implementation quantitatively demonstrate that Diff-Index offers various performance/consistency balance and satisfac-tory scalability while avoiding global coordination. Sync-insert and async-simple can reduce 60%-80 % of the overall index update latency when compared to the baseline sync-full; async-simple can achieve superior index update per-formance with an acceptable inconsistency. Diff-Index ex-ploits LSM features such as versioning and the flush-compact process to achieve goals of concurrency control and failure Wei Tan 0001, Sandeep Tata, Yuzhe Tang, Liana L. Fong |
EDBT | 2 |
| 2013 | Sparkler: supporting large-scale matrix factorizationabstractLow-rank matrix factorization has recently been applied with great success on matrix completion problems for applications like recommendation systems, link predictions for social networks, and click prediction for web search. However, as this approach is applied to increasingly larger datasets, such as those encountered in web-scale recommender systems like Netflix and Pandora, the data management aspects quickly become challenging and form a road-block. In this paper, we introduce a system called Sparkler to solve such large instances of low rank matrix factorizations. Sparkler extends Spark, an existing platform for running parallel iterative algorithms on datasets that fit in the aggregate main memory of a cluster. Sparkler supports distributed stochastic gradient descent as an approach to solving the factorization problem -- an iterative technique that has been shown to perform very well in practice. We identify the shortfalls of Spark in solving large matrix factorization problems, especially when running on the cloud, and solve this by introducing a novel abstraction called "Carousel Maps" (CMs). CMs are well suited to storing large matrices in the aggregate memory of a cluster and can efficiently support the operations performed on them during distributed stochastic gradient descent. We describe the design, implementation, and the use of CMs in Sparkler programs. Through a variety of experiments, we demonstrate that Sparkler is faster than Spark by 4x to 21x, with bigger advantages for larger problems. Equally importantly, we show that this can be done without imposing any changes to the ease of programming. We argue that Sparkler provides a convenient and efficient extension to Spark for solving matrix factorization problems on very large datasets. Boduo Li, Sandeep Tata, Yannis Sismanis |
EDBT | 2 |
| 2012 | Clydesdale: structured data processing on MapReduceabstractMapReduce has emerged as a promising architecture for large scale data analytics on commodity clusters. The rapid adoption of Hive, a SQL-like data processing language on Hadoop (an open source implementation of MapReduce), shows the increasing importance of processing structured data on MapReduce platforms. MapReduce offers several attractive properties such as the use of low-cost hardware, fault-tolerance, scalability, and elasticity. However, these advantages have required a substantial performance sacrifice. Tim Kaldewey, Eugene J. Shekita, Sandeep Tata |
EDBT | 3 |
| 2012 | Clydesdale: structured data processing on hadoopabstractThere have been several recent proposals modifying Hadoop, radically changing the storage organization or query processing techniques to obtain good performance for structured data processing. We will showcase Clydesdale, a research prototype for structured data processing on Hadoop that can achieve dramatic performance improvements over existing solutions, without any changes to the underlying MapReduce implementation. Clydesdale achieves this through a novel synthesis of several techniques from the database literature and carefully adapting them to the Hadoop environment. On the star schema benchmark, we show that Clydesdale is on average 38x faster than Hive, the dominant approach for structured data processing on Hadoop today. To the best of our knowledge, Clydesdale is the fastest solution for processing workloads on structured data sets that fit a star schema on Hadoop. Attendees will be able to run queries on the data from the star schema benchmark on a remote Hadoop cluster with Clydesdale and Hive installed, and get a breakdown of the time taken to execute the query. Attendees will also be able to pose their own queries using ClyQL -- a novel embedded DSL in Scala that can be used to rapidly prototype star join queries. With this demonstration, we hope to convince the attendees that unlike previously thought, Hadoop can indeed efficiently support structured data processing. Andrey Balmin, Tim Kaldewey, Sandeep Tata |
SIGMOD Conference | 3 |
| 2011 | Column-Oriented Storage Techniques for MapReduceabstractUsers of MapReduce often run into performance problems when they scale up their workloads. Many of the problems they encounter can be overcome by applying techniques learned from over three decades of research on parallel DBMSs. However, translating these techniques to a Map-Reduce implementation such as Hadoop presents unique challenges that can lead to new design choices. This paper describes how column-oriented storage techniques can be incorporated in Hadoop in a way that preserves its popular programming APIs. We show that simply using binary storage formats in Hadoop can provide a 3x performance boost over the naive use of text files. We then introduce a column-oriented storage format that is compatible with the replication and scheduling constraints of Hadoop and show that it can speed up MapReduce jobs on real workloads by an order of magnitude. We also show that dealing with complex column types such as arrays, maps, and nested records, which are common in MapReduce jobs, can incur significant CPU overhead. Finally, we introduce a novel skip list column format and lazy record construction strategy that avoids deserializing unwanted records to provide an additional 1.5x performance boost. Experiments on a real intranet crawl are used to show that our column-oriented storage techniques can improve the performance of the map phase in Hadoop by as much as two orders of magnitude. Avrilia Floratou, Jignesh M. Patel, Eugene J. Shekita, Sandeep Tata |
Proc. VLDB Endow. | 4 |
| 2011 | Using Paxos to Build a Scalable, Consistent, and Highly Available DatastoreabstractSpinnaker is an experimental datastore that is designed to run on a large cluster of commodity servers in a single datacenter. It features key-based range partitioning, 3-way replication, and a transactional get-put API with the option to choose either strong or timeline consistency on reads. This paper describes Spinnaker's Paxos-based replication protocol. The use of Paxos ensures that a data partition in Spinnaker will be available for reads and writes as long a majority of its replicas are alive. Unlike traditional master-slave replication, this is true regardless of the failure sequence that occurs. We show that Paxos replication can be competitive with alternatives that provide weaker consistency guarantees. Compared to an eventually consistent datastore, we show that Spinnaker can be as fast or even faster on reads and only 5% to 10% slower on writes. Jun Rao, Eugene J. Shekita, Sandeep Tata |
Proc. VLDB Endow. | 3 |
| 2011 | Efficient and Accurate Discovery of Patterns in Sequence Data SetsabstractExisting sequence mining algorithms mostly focus on mining for subsequences. However, a large class of applications, such as biological DNA and protein motif mining, require efficient mining of “approximate” patterns that are contiguous. The few existing algorithms that can be applied to find such contiguous approximate pattern mining have drawbacks like poor scalability, lack of guarantees in finding the pattern, and difficulty in adapting to other applications. In this paper, we present a new algorithm called FLexible and Accurate Motif DEtector (FLAME). FLAME is a flexible suffix-tree-based algorithm that can be used to find frequent patterns with a variety of definitions of motif (pattern) models. It is also accurate, as it always finds the pattern if it exists. Using both real and synthetic data sets, we demonstrate that FLAME is fast, scalable, and outperforms existing algorithms on a variety of performance metrics. In addition, based on FLAME, we also address a more general problem, named extended structured motif extraction, which allows mining frequent combinations of motifs under relaxed constraints. Avrilia Floratou, Sandeep Tata, Jignesh M. Patel |
IEEE Trans. Knowl. Data Eng. | 2 |
| 2010 | Efficient and accurate discovery of patterns in sequence datasetsabstractExisting sequence mining algorithms mostly focus on mining for subsequences. However, a large class of applications, such as biological DNA and protein motif mining, require efficient mining of ¿approximate¿ patterns that are contiguous. The few existing algorithms that can be applied to find such contiguous approximate pattern mining have drawbacks like poor scalability, lack of guarantees in finding the pattern, and difficulty in adapting to other applications. In this paper, we present a new algorithm called FLAME (FLexible and Accurate Motif DEtector). FLAME is a flexible suffix tree based algorithm that can be used to find frequent patterns with a variety of definitions of motif (pattern) models. It is also accurate, as it always find the pattern if it exists. Using both real and synthetic datasets, we demonstrate that FLAME is fast, scalable, and outperforms existing algorithms on a variety of performance metrics. Using FLAME, it is now possible to mine datasets that would have been prohibitively difficult with existing tools. Avrilia Floratou, Sandeep Tata, Jignesh M. Patel |
ICDE | 2 |
| 2008 | FLAME: Shedding Light on Hidden Frequent Patterns in Sequence DatasetsabstractExisting database sequence mining algorithms focus on mining for subsequences. However, for many emerging applications, the subsequence model is inadequate for detecting interesting patterns. Often, an approximate substring model better accommodates the notion of a noisy pattern. In this paper, we present a powerful new model for approximate pattern mining. We show that this model can be used to capture the notion of an approximate match for a variety of different applications. We also present a novel, suffix tree based pattern mining algorithm called FLAME and demonstrate that it is a fast, accurate, and scalable method for discovering hidden patterns in large sequence databases. Sandeep Tata, Jignesh M. Patel |
ICDE | 1 |
| 2008 | SQAK: doing more with keywordsabstractToday's enterprise databases are large and complex, often relating hundreds of entities. Enabling ordinary users to query such databases and derive value from them has been of great interest in database research. Today, keyword search over relational databases allows users to find pieces of information without having to write complicated SQL queries. However, in order to compute even simple aggregates, a user is required to write a SQL statement and can no longer use simple keywords. This not only requires the ordinary user to learn SQL, but also to learn the schema of the complex database in detail in order to correctly construct the required query. This greatly limits the options of the user who wishes to examine a database in more depth. Sandeep Tata, Guy M. Lohman |
SIGMOD Conference | 1 |
| 2007 | Periscope/SQ: Interactive Exploration of Biological Sequence Databases
Sandeep Tata, Willis Lang, Jignesh M. Patel |
VLDB | 1 |
| 2006 | Declarative Querying for Biological SequencesabstractThe ongoing revolution in life sciences research is producing vast amounts of genetic and proteomic sequence data. Scientists want to pose increasingly complex queries on this data, but current methods for querying biological sequences are primitive and largely procedural. This limits the ease with which complex queries can be posed, and often results in very inefficient query plans. There is a growing and urgent need for declarative and efficient methods for querying biological sequence data. In this paper, we introduce a system called Periscope/SQ which addresses this need. Queries in our system are based on a well-defined extension of relational algebra. We introduce new physical operators and support for novel indexes in the database. As part of the optimization framework, we describe a new technique for selectivity estimation of string pattern matching predicates that is more accurate than previous methods. We also describe a simple, yet highly effective algorithm to optimize sequence queries. Finally, using a real-world application in eye genetics, we show how Periscope/SQ can be used to achieve a speedup of two orders of magnitude over existing procedural methods! Sandeep Tata, Jignesh M. Patel, James S. Friedman, Anand Swaroop |
ICDE | 1 |
| 2005 | Practical methods for constructing suffix trees
Yuanyuan Tian 0001, Sandeep Tata, Richard A. Hankins, Jignesh M. Patel |
VLDB J. | 2 |
| 2004 | Practical Suffix Tree Construction
Sandeep Tata, Richard A. Hankins, Jignesh M. Patel |
VLDB | 1 |
| 2003 | PiQA: An Algebra for Querying Protein Data SetsabstractLife science researchers frequently need to query large protein data sets in a variety of different ways. Protein data sets have a rich structure that includes its primary structure, which is described as a sequence of amino acids, and its secondary structure, which is described as a sequence of folding patterns of the protein. Both these structures are important as the amino acid sequence is often used to find homologous proteins, and the secondary structure can produce important hints about the functionality of proteins. While there are tools for querying each of these structures independently, there are no tools for declarative querying on both these structures. Even the tools that allow querying on either one of these structures are not based on any formal algebra, and as a result require complex rewriting of the tools programming logic when the "query evaluation plan" changes. This paper introduces PiQA, a Protein Query Algebra, which provides a rich set of algebraic operations on both the primary and secondary structure of proteins. Using PiQA one can pose several interesting complex queries involving both the primary and the secondary structure of proteins. In addition, simple existing tools that query only on the primary structure, such as BLAST, can also be expressed in this algebra. PiQA is an important first step in developing an algebra that can form the basis of a declarative querying language for querying protein data sets. Sandeep Tata, Jignesh M. Patel |
SSDBM | 1 |