Abhijeet Mohapatra

Ph.D. Candidate
Advisor: Michael Genesereth

Computer Science Department
Stanford University

Research Publications and Technical Reports Inventor Profile Internships Teaching Course Projects at Stanford Other Presentations Affiliations Artwork


Aggregates in logic programming.

Other interests: data integration, data mining, data and policy management, column stores, database compression.

Publications and Technical Reports

Author(s) Title Series Year Link
Abhijeet Mohapatra, Michael Genesereth Incremental Maintenance of Aggregate Views FoIKS 2014 pdf
Abhijeet Mohapatra, Michael Genesereth An Incremental Algorithm to Optimally Maintain Aggregate Views LPAR 2013 pdf slides
Abhijeet Mohapatra, Michael Genesereth Reformulating aggregate queries using views SARA 2013 pdf slides
Abhijeet Mohapatra, Michael Genesereth Method and System for Database Storage Management Patent Publication 2013 pdf
Abhijeet Mohapatra, Michael Genesereth Aggregates in Datalog under set semantics Technical Report 2012 pdf
Abhijeet Mohapatra, Ravishankar Ramamurthy, Raghav Kaushik Optimizing fine grained access control using authorization indexes Patent Publication 2012 pdf
Abhijeet Mohapatra, Ravishankar Ramamurthy Efficient database compression Patent Publication 2012 pdf
Abhijeet Mohapatra, Michael Genesereth Incrementally maintaining run-length encoded attributes in column stores IDEAS 2012 pdf slides
Abhijeet Mohapatra Optimal Sort Ordering in Column Stores is NP-Complete Technical Report 2009 pdf
Abhijeet Mohapatra Database techinques in crowd simulations and the scheduling problem in SDF graphs Undergraduate Thesis
Advisor: P. P. Chakrabarti
2008 pdf
Abhijeet Mohapatra, R. K. Shayamsundar Capturing safety properties of stream queries in a temporal logic framework Indian Academy of Sciences Fellowship 2006

Inventor Profile

Patent Reference Invention Summary
A technique to incrementally update compressed relations in column stores. A compressed attribute is updated in time that is logarithmic in the number of the distinct values of that attribute. Batch updates can be performed in time that is constant per updated tuple. No technique can perform faster updates in an asymptotic sense.
Architecture that is an index mechanism which optimizes complex queries that result from enforcing fine grained access control. The architecture addresses the problem of efficient query evaluation in the presence of fine grained access control.
A method for compressing a database relation by leveraging an optimal ordering of tuples and composition of compression operators.


Location Mentor(s) Date Project Summary
Microsoft Research, Redmond Ravishankar Ramamurthy Summer 2010 Auto-Admin Project
Proposed and implemented a mechanism to optimize fine-grained access control in database queries. For a variety of authorization policies, an order of magnitude speed-up was observed on TPC-H benchmark. (USPTO Publication#: 20120330925)
Microsoft Research, Redmond Ravishankar Ramamurthy Summer 2009 Auto-Admin Project
Proposed and implemented an extensible framework to compress database relations by composing compression techniques. The compression achieved on syntenthic as well as real datasets using our framework was an order of magnitude larger than state-of-art compressors such as WinZip and xMill. (USPTO Publication#: 20120150877)
DB Group, Cornell University Johannes Gehrke, Al Demers and Walker White Summer 2007 Scalable Games Project
(a) Proposed a novel architecture which decouples the sequencial modules in a traditional game loop.
(b) Proposed a new algorithm for collision-free navigation in crowd simulations.
IBM Research Lab, New Delhi R. K. Shayamsundar Summer 2006
Developed a formal model to answer continuous queries on complex event streams in the temporal logic framerwork of Lustre.


Teaching Assistant for CS 157: Computational Logic (Fall 2010).

Course Projects at Stanford

Course Date Instructor Topic
CS 322 Fall 2009 Jure Leskovec Item-basket Revenue Maximization pdf
CS 345A Winter 2009 Jeffrey D. Ullman (a) Towards a hybrid approach to Netflix Challenge pdf
(b) Analysis of Netflix Data pdf

Other Presentations

Presenter(s) Title Venue Year Link
Abhijeet Mohapatra Digital Department Stanford CS Annual Affiliates Meeting 2013 slides
Abhijeet Mohapatra Efficiently Updating Column Stores Stanford CS Annual Affiliates Meeting 2012 slides


Stanford Logic Group, Infolab