To reach me, please email me at:

f i r s t n a m e at firstname.org.


OHI/O: Ohio State's Hackathon Program

We created the OHI/O Program in 2013, with the goal of fostering the fledgling tech culture at Ohio State. In addition to the flagship annual OHI/O Hackathon that it runs, the program has helped create spinoff events such as the hardware-focused Makeathon, and the community-focused TownHack, and promotes hacker/maker activity on campus through travel scholarships and seed grants. In 3 years, OHI/O has grown from a single grassroots event to the largest hackathon program in Ohio, with over 500 students attending the latest Fall event.

The annual flagship Hackathon at Ohio State focuses on being a healthy and informal learning experience. This is achieved by the presence of mentors and judges (comprised of faculty, staff, and alumni engineers from top tech companies) who guide the students to learn new concepts as they build out their creations. Bootstrapped with approximately $20K from the university, the event is now self-funded, and has more than doubled in attendance each year of its existence: 100+ in 2013, 200+ in 2014. This year, the event grew to over 500 student participants from universities in Ohio and beyond. The organization of the event was an excellent educational experience as well, with over 20 student organizers spanning 6 student groups, over 20 industry partners, 50 mentors, and 60 judges.

As cataloged in our upcoming SIGCSE paper, feedback from students and alumni have been extremely encouraging through the years, and the renewed energy and ideas from the event directly impacted course enrollment and creation of new collaborative research projects.

Team OHI/O 2016

Paper: Hackathons as an Informal Learning Platform

  • Arnab Nandi, Meris Mandernach: “Hackathons as an Informal Learning Platform”, ACM SIGCSE 2016 [pdf]

Slides & Photos


  • 2014 TV report:
  • Ohio State’s President Drake’s Greeting:
  • 2016 Recap:
  • 2014 Recap:

Team OHI/O 2015


Come Work with Arnab!

I am always looking for undergraduate, PhD students and Post-docs to build the next generation of interactive database systems. The group works on fun, fast-paced research in the areas of big data analytics, interactive user interfaces, statistical methods, and next-generation mobile and web technologies.
To work with the group, please contact me with a link to an example of technical work you have done before (e.g., source code or demo of software, a research paper, a startup you founded, a mathematical proof).
Some promo videos on why you should come to Ohio State , and Columbus, OH.

Available (funded) positions in my group:


Postdoctoral Researcher / Research Engineer (1yr term starting immediately, funded by industry partners / OSU Tech Commercialization)

The interactive data systems group has an open position for a postdoctoral researcher / research engineer in the big data analytics research area. The group works on research challenges related to empowering humans to effectively interact with data.

The specific position is related to our current low-latency data cubing efforts project, and other topics related to big data analytics and business intelligence software infrastructure. The goal of the project is to build upon our prior work and develop / test / validate production-ready MVPs in real-world environments. For this specific position you should be interested and have experience in some or all of the following: distributed systems, cloud environments (EC2, Azure, GCE), algorithms (sampling, approximation), Java / Scala, Postgres / Spark / Impala, Pig / Hive.

You should be able to work well in team settings — this includes collaboratively writing code, publishing papers, contributing to the patenting process, and working with industry partners for deployment, testing, and validation. Proven communication skills are essential to be successful.

Your background:

  • Background in data base systems / data infrastructure
  • Research background in database systems, distributed systems, or related fields
  • Some practical work experience in industry research or development
  • At least 5 year experience with Java
  • Experience with large code bases, particularly in open source
  • PhD in computer science, information systems or a related field preferred

To apply, please email Arnab [ firstname @ cse dot osu . edu ] with your (1) resume (2) link to one representative first author paper, and (3) examples of prior codebases you have contributed to (GitHub profile, JIRAs, etc.)


PhD / Undergraduate Researcher (multi-year term starting Fall 2017, funded by National Science Foundation)

The interactive data systems group has an open position for 1 doctoral researcher and 1 undergrad (REU) researcher in the next-generation data experiences research theme. The group works on research challenges related to empowering humans to effectively interact with data. The specific position is related to our current querying beyond keyboards, and other topics related to interactive visualization, gestural querying, and natural user interfaces.

For this specific position you should be interested and have experience in some or all of the following: algorithms, statistics / optimization, data mining, data visualization, with expertise in one or more of Javascript, Unity, iOS, Android, and python.

You should be able to work well in team settings — this includes collaboratively writing code, rapid prototyping, publishing papers, contributing to the patenting process and so forth. Proven communication skills are essential to be successful.

Your background:

  • BS (for PhD applicants) in computer science, information systems, math, statistics, or a related field
  • Background in data base systems / data infrastructure
  • Research background in database systems, distributed systems, or related fields

To apply, please read this post





Hackathon starts Nov 2 at 3:00pm at 18th Ave. Library

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High-end Computing Systems Group Faculty


Systems Seminar Fridays at 3:30pm in DL 480

Gagan Agrawal
High Performance, Data-Intensive, and Cloud Computing, Middleware/Compilers, Data/Web Mining

Srini Parthasarathy
Data Mining, Parallel & Distributed Computing Systems, Network Science at Scale (Social and Biological Networks)

Arnab Nandi
Database Systems, Large-scale Analytics, Data Interaction

P. (Saday) Sadayappan
Performance Optimization, Compilers/Runtime Systems

Christopher Stewart
Power management, Data-intensive services, Empirical studies

Spyros Blanas
Database Systems, Main Memory Architectures

Radu Teodorescu
Computer Architecture, Energy-efficient computing, Reliability

Xiaodong Zhang
Distributed Systems, Memory Systems (also Networking)

D. K. Panda
Architecture, Networking, Programming Models, Accelerators, Cloud Computing, File systems and Storage, and Power-Aware Designs, Big Data

Feng Qin
Operating Systems, System Security and Dependability, Cloud Computing, and Mobile Computing


Things I have worked on

PhD Research: Usable Database Search Qunits: Queried Units in Database Search Database Autocompletion Effective Phrase Prediction
Non-Thesis Research Using Clicklogs for Schema Matching Large Scale Data Cubing BANKS: Browsing and Keyword Search Searching Personal Information Networks
Other projects BaconSnake: Python UDFs for Pig pdf.cx: PDF Viewing for the Web y!Vmail Magic Bus for the iPhone TimepassTown Blogsnob idya Research

Arnab's plans


Arnab Nandi


Arnab Nandi
Assistant Professor
Computer Science & Engineering
The Ohio State University

Office: DL 687 [send email / phone: 614-292-6377]

Picture of Arnab    

Arnab’s research is in the area of database systems, focusing on user-facing challenges in large-scale data analytics and interactive data exploration. The goal of his group is to empower humans to effectively interact with data. This involves solving problems that span the areas of databases, visualization, human-computer interaction, and information retrieval.

Arnab serves on the organizing committee of the annual Workshop on Human-in-the-Loop Data Analytics (HILDA). Arnab is also a founder of The STEAM Factory, a collaborative interdisciplinary research and public outreach initiative, and faculty director of the OHI/O Hackathon Program, that uses hackathons as an informal learning platform. Arnab is a recipient of the NSF CAREER Award, a Google Faculty Research Award, and the Ohio State College of Engineering Lumley Research Award. He is also the recipient of the IEEE TCDE Early Career Award for contributions towards user-focused data interaction.


Want to work with Arnab? Please read this first.



Selected Projects



  • Our BinGo full paper was awarded Best Paper Honorable Mention at ACM IUI 2017!
  • Meraj’s VLDB full paper on Data Tweening is now available! (Collaboration with Larry Xu and Joe Hellerstein from Berkeley.)
  • Thank you to the volunteers, mentors, judges, sponsors, organizers, and above all the 770+ student participants who made HackOHI/O 2016 a huge success! A video recap is available.



  • Organizer / co-Chair: HILDA 2016
  • Demonstrations Chair: ICDE 2017
  • Publicity co-Chair: SIGMOD 2017
  • Program Committees: SIGMOD (2015, 2016), VLDB (2013, 2014, 2015, 2016, 2017), SOCC (2013), ICDE (2013)
  • Reviewer: SIGMOD, TKDE, TODS, PVLDB, VLDB Journal, WWW
  • Advisory: Ohio State Discovery Themes Data Analytics Collaborative Advisory Committee
  • Informal Learning: Co-founder / faculty director of the OHI/O Hackathon program that fosters a tech culture at Ohio State by hosting Ohio State’s annual hackathons (100+ students in 2013, 200+ in 2014, 500+ in 2015) and supporting related efforts such as the Makeathon hardware hackathon.
  • Collaborative Research and Dissemination: Co-founder / Director of The STEAM Factory initiative that spans over 70 faculty, staff and post-doc members.


Publications [dblp] [citations] [by year]

Gestural Querying: (Supported by NSF CAREER Award #1453582)
Next-generation data interfaces will look a lot different than today’s computers. What happens to databases when gestures are the sole mode of interaction?

  • Arnab Nandi: Querying Without Keyboards: CIDR 2013 (Vision Track: Best Paper Award) [pdf] [concept video]
  • Juan Felipe Beltran, Ziqi Huang, Azza Abouzied, Arnab Nandi: Don’t Just Swipe Left, Tell Me Why:Enhancing Gesture-based Feedback with Reason Bins: IUI 2017 [to appear] [pdf]
  • Jiongqian Liang, David Fuhry, David Maung, Roger Crawfis, Lynne Gauthier, Arnab Nandi, Srinivasan Parthasarathy: Data Analytics Framework for A Game-based Rehabilitation System: SDM Workshop on Data Mining for Medicine and Healthcare 2016 [pdf]
  • Lilong Jiang, Arnab Nandi: SnapToQuery: Providing Interactive Feedback during Exploratory Query Specification: VLDB 2015 [pdf] [video]
  • Lilong Jiang, Arnab Nandi: Designing Interactive Query Interfaces to Teach Database Systems in the Classroom: CHI 2015 (Work-In-Progress) [pdf] [slides]
  • Arnab Nandi: Breathing Life into Database Textbooks: CIDR 2015 (Extended Abstract) [pdf]
  • Ziqi Huang, Juan Felipe Beltran, Azza Abouzied, Arnab Nandi: Beyond Binary Gestures: Exploring Documents using Touch Interfaces: CHI 2015 (Work-In-Progress) [pdf]
  • Arnab Nandi, Lilong Jiang, Michael Mandel: Gestural Query Specification: VLDB 2014 [pdf] [slides] [video]
  • Lilong Jiang, Arnab Nandi, Michael Mandel: GestureQuery: A Multitouch Database Query Interface: VLDB 2013 (demo) [pdf]
  • Arnab Nandi, Michael Mandel: The Interactive Join: Recognizing Gestures for Database Queries: CHI 2013 (Work-In-Progress) [pdf]

Large Scale / Interactive Analytics: (Supported by NSF Awards #1422977 and #1527779)
How do we support low-latency, human-in-the-loop, visual, and exploratory analysis over extremely large datasets?

  • Meraj Ahmed Khan, Larry Xu, Arnab Nandi, Joseph Hellerstein: Data Tweening: Incremental Visualization of Data Transforms: VLDB 2017 [pdf]
  • Roee Ebenstein, Niranjan Kamat, Arnab Nandi: FluxQuery: An Execution Framework for Highly Interactive Query Workloads: SIGMOD 2016 [pdf]
  • Niranjan Kamat, Arnab Nandi: A Closer Look at Variance Implementations In Modern Database Systems: SIGMOD Record 2015 [arXiv preview]
  • Eugene Wu, Arnab Nandi: Towards Perception-aware Interactive Data Visualization Systems: Data Systems for Interactive Analysis (DSIA) Workshop 2015
  • Arnab Nandi, Ziqi Huang, Man Cao, Micha Elsner, Lilong Jiang, Srinivasan Parthasarathy, Ramiya Venkatachalam: Interactive Tweaking of Text Analytics Dashboards DNIS 2015 / Springer LNCS [pdf]
  • Prasanth Jayachandran, Niranjan Kamat, Kathik Tunga, Arnab Nandi: Combining User Interaction, Speculative Query Execution and Sampling in the DICE System: VLDB 2014 (demo) [pdf] [video]
  • Niranjan Kamat, Prasanth Jayachandran, Kathik Tunga, Arnab Nandi: Distributed Interactive Cube Exploration: ICDE 2014 [pdf] [slides]
  • Arnab Nandi, Cong Yu, Philip Bohannon, Raghu Ramakrishnan: Data Cube Materialization and Mining over MapReduce: IEEE TKDE “Best Papers in ICDE 2011” Special Issue [pdf]

Guided Interaction:

  • David Fuhry, Yang Zhang, Venu Satuluri, Arnab Nandi, Srinivasan Parthasarathy: PLASMA-HD: Probing the LAttice Structure and MAkeup of High-dimensional Data: VLDB 2013 (demo) [pdf]
  • Manish Singh, Arnab Nandi, H. V. Jagadish: Skimmer: Rapid Scrolling of Relational Query Results: SIGMOD 2012 [pdf] [slides]
  • Arnab Nandi, H. V. Jagadish: Guided Interaction: Rethinking the Query-Result Paradigm: VLDB 2011 (Challenges & Visions Track) [pdf] [slides]


Database Usability:

  • H. V. Jagadish , Arnab Nandi, Li Qian: Organic Databases: DNIS 2011 [pdf]
  • Arnab Nandi, H. V. Jagadish: Qunits: queried units in database search: CIDR 2009 [html] [pdf] [slides]
  • H. V. Jagadish, Adriane Chapman, Aaron Elkiss, Magesh Jayapandian, Yunyao Li, Arnab Nandi, Cong Yu: Making database systems usable: SIGMOD 2007 [pdf]
  • Magesh Jayapandian, Adriane Chapman, V. Glenn Tarcea, Cong Yu, Aaron Elkiss, Angela Ianni, Bin Liu, Arnab Nandi, Carlos Santos, Philip Andrews, Brian D. Athey, David J. States, H. V. Jagadish: Michigan Molecular Interactions (MiMI): putting the jigsaw puzzle together: Nucleic Acids Research 35(Database-Issue) 2007

Human-powered Computation:

  • Akash Das Sarma, Ayush Jain, Arnab Nandi, Aditya Parameswaran, Jennifer Widom: JellyBean: Crowd-Powered Image Counting Algorithms: Technical Report [pdf]
  • Manirupa Das, Micha Elsner, Arnab Nandi, Rajiv Ramnath: TopChurn: Maximum Entropy Churn Prediction Using Topic Models Over Heterogeneous Signals: WWW Web Science 2015 (Invited to Journal of Web Science as one of the Best Papers from WWW Web Science) [pdf]

Search / Query Log Mining / Data Integration / Privacy / Social / Education:

  • Yi Wang, Arnab Nandi, Gagan Agrawal: SAGA: array storage as a DB with support for structural aggregations: SSDBM 2014 [pdf]
  • Arnab Nandi, Meris Mandernach: Hackathons as an Informal Learning Platform: SIGCSE 2016 [pdf]
  • Arnab Nandi, Stelios Paparizos, John Shafer, Rakesh Agrawal: With a Little Help from My Friends: ICDE 2013 (demo) [pdf]
  • Daniel Fabbri, Arnab Nandi, Kristen LeFevre, H. V. Jagadish: PrivatePond: Outsourced Management of Web Corpuses: WebDB 2009 [html] [pdf]
  • Soumen Chakrabarti, Jeetendra Mirchandani, Arnab Nandi: SPIN: searching personal information networks: SIGIR 2005 (demo) [pdf]

This research is made possible through the support of the National Science Foundation, National Institutes of Health, Yahoo! Labs, and Google Research.


I also have a sporadically maintained blog.



Arnab received his Ph.D. in Computer Science from the University of Michigan where he was awarded the Yahoo! Research PhD Fellowship. At Michigan, he was part of the Database Research Group and was advised by H. V. Jagadish. His thesis addressed the problem of making search in databases easier, as part of the group’s broader goal of making databases usable. During internships at Yahoo! Research, Google and Microsoft Research, Arnab worked on various large-scale systems, dealing with problems in web and social search, data integration and data cubing.

During his PhD, Arnab was involved with the Michigan CSE Graduate Society board in various capacities including Secretary, Treasurer and President.
Before graduate school, he worked with Prof. Soumen Chakrabarti and Prof. S. Sudarshan at IIT Bombay. Arnab was part of the BANKS and SPIN projects, where he worked on various aspects of ranking graph-based data.
During his undergraduate years at the University of Delhi, Arnab teamed up with 2 of his college-mates to start idya Research , where he developed novel web-based applications.
He has also had the opportunity of interning with Media Lab Asia, and the technical research group at Yahoo! Bangalore. He worked with the Question Answering group at Google in the summer of 2007, the Database Group at Microsoft Research in the summer of 2008, the Web Information Management Group at Yahoo! Research in the summer of 2009 and the Search Labs group at Microsoft Research Silicon Valley in the summer of 2011.
Apart from research, he has also been a contributor to Drupal, the framework that runs this website. Arnab created the Captcha and Similar Entries modules, which are now maintained by other members of the Drupal community. He also wrote BaconSnake, parts of which eventually made its way into Apache Pig 0.8’s Jython UDF feature.


TimepassTown.com was the website I had created when I was fresh out of high school. With the aim of coming up with a better way to pass time on the Internet, TpT (as we fondly called it) evolved in three iterations into a community-based literary showcase. People would submit poetry, stories, weblog posts, and other interesting content covering a myriad of topics.

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