Renata Borovica-Gajic

I work as a Lecturer (Assistant Professor) in Data Analytics in the School of Computing and Information Systems (CIS) at the University of Melbourne. I obtained my PhD from EPFL, Switzerland, where I worked in the Data-Intensive Applications and Systems Laboratory (DIAS). My research focuses on enabling faster, more predictable and cheaper data analysis. To optimize performance and cost of data analytics services, I envision database systems as adaptive engines able to adjust their query execution strategy at runtime to fit the characteristics of the queries, data and underlying hardware. I am also interested in the broad topics of scientific data management, data exploration, query optimization, physical database design, and hardware-software co-design. More details can be found in my CV.

Renata Borovica-Gajic photo


Cheap data analysis with Skipper

This project looks at exploiting new hardware to decrease the cost of data analytics storage infrastructure. In particular, Skipper is an end-to-end query processing framework built by using cold storage devices as an underlying storage medium. Skipper employs a (cold) storage-driven query execution model based on multi-way joins combined with efficient cache management and I/O scheduling strategies to hide the non-uniform access latencies of cold storage. As a result, Skipper offers performance comparable to the performance of systems storing data on HDD, with a substantially lower cost. PDF

Predictable query performance with Smooth Scan

Smooth Scan aims at preventing performance degradation coming from suboptimal query plan decisions. To achieve optimal performance for all query inputs, Smooth Scan uses continuous adaptation and morphing at runtime by transforming from one physical alternative to another (i.e., from an index access to sequential scan). With Smooth Scan, an access path strategy is progressively transformed into an optimal form based on the operator selectivity and result distribution observed during query execution. As a result, a system with Smooth Scan requires no access path decisions up front nor does it need accurate statistics to provide good performance. PDF

Fast data exploration with NoDB

NoDB enables fast and efficient data exploration by removing data loading as a prerequisite to data querying. Instead, NoDB enables query processing capabilities directly over data files, and uses the user queries as a driver for partial and incremental data loading and performance tuning. To mask the overhead of raw file data access and speed up future queries, NoDB builds and progressively refines auxiliary design structures (positional indexes, data caches and statistics) during query execution. As a result, NoDB matches the performance of traditional database systems that process already loaded data. PDF


arXiv:1902.07500, 2019. A Note on Bounding Regret of the C2UCB Contextual Combinatorial Bandit. B. Oetomo, M. Perera, R. Borovica-Gajic, B. I. P. Rubinstein. PDF Link

VLDB Journal, 2018. Smooth Scan: Robust Access Path Selection without Cardinality Estimation. R. Borovica-Gajic, S. Idreos, A. Ailamaki, M. Zukowski and C. Fraser. PDF* Link BibTex

DASFAA, 2018. Finding All Nearest Neighbors with a Single Graph Traversal. Y. Xu, J. Qi, R. Borovica-Gajic, and L. Kulik. PDF Slides Link BibTex

Dagstuhl Reports 7(5), 2017. Robust Performance in Database Query Processing (Dagstuhl Seminar 17222). R. Borovica-Gajic, G. Graefe, and A. Lee. PDF BibTex

ADMS, 2017. The five minute rule thirty years later and its impact on the storage hierarchy. R. Appuswamy, R. Borovica-Gajic, G. Graefe, and A. Ailamaki. PDF Slides BibTex

PhD Thesis, EPFL, 2016. Toward timely, predictable and cost-effective data analytics. R. Borovica-Gajic. PDF Slides Poster

VLDB, 2016. Cheap Data Analytics Using Cold Storage Devices. R. Borovica-Gajic, R. Appuswamy, and A. Ailamaki. PDF Slides Poster BibTex

ICDE, 2015. Smooth Scan: Statistics-oblivious Access Paths. R. Borovica-Gajic, S. Idreos, A. Ailamaki, M. Zukowski and C. Fraser. PDF Slides Poster BibTex

CACM, Research Highlights, 2015. NoDB: Efficient Query Execution on Raw Data Files. I. Alagiannis, R. Borovica-Gajic, M. Branco, S. Idreos, and A. Ailamaki. PDF BibTex

VLDB, 2012. NoDB in Action: Adaptive Query Processing on Raw Data (demo). I. Alagiannis, R. Borovica, M. Branco, S. Idreos and A. Ailamaki. PDF Poster BibTex

DBTest, 2012. Automated Physical Designers: What You See is (Not) What You Get. R. Borovica, I. Alagiannis and A. Ailamaki. PDF Slides Poster BibTex

SIGMOD, 2012. NoDB: Efficient Query Execution on Raw Data Files. I. Alagiannis, R. Borovica, M. Branco, S. Idreos and A. Ailamaki. PDF Slides Poster BibTex

DEB, 2011. Challenges and Opportunities in Self-Managing Scientific Databases. T. Heinis, M. Branco, I. Alagiannis, R. Borovica, F. Tauheed and A. Ailamaki. PDF BibTex


US Patent: 9298754. Query management system and engine allowing for efficient query execution on raw details. A. Ailamaki, S. Idreos, I. Alagiannis, R. Borovica, M. Branco. Link


Database Systems (INFO20003). University of Melbourne, 2017, 2018, 2019 (offered every semester).

Programming I (C course) with Prof. Jean-Luc Desbiolles. EPFL, Spring 2014.

Project in informatics (C++ course) with Prof. Jamila Sam. EPFL, Fall 2013.

Introduction to object oriented programming (Java course) with Prof. Jamila Sam. EPFL, Fall 2012.

Computer-aided engineering (C++ course) with Prof. Jamila Sam. EPFL, Spring 2012, 2013.

Introduction to programming (Java course) with Prof. Jamila Sam. EPFL, Fall 2011, 2014.

Programming (Java course) with Prof. Thomas Lochmatter. EPFL, Spring 2011.

Invited talks

A tale of learning databases. Australasian Database Conference (ADC), 2019. Slides

Tips and tricks for effective PhD. University of Queensland, Data Science Colloquium, 2018. Slides

Smooth Scan: Statistics-oblivious access paths under looking glass. Dagstuhl Seminar, 2017. Slides

Towards timely, predictable and cost-effective data analytics. University of Melbourne, 2016. Slides

Professional Service

Conference Program Committee:

  • 2020: SIGMOD, VLDB
  • 2019: ICDE, SIGMOD, VLDB, ADC, WomENcourage, GHC
  • 2018: SYSTOR, DBTest, WomENcourage

Workshop Organizer:

  • R. Borovica-Gajic, G. Graefe, A. Lee. 2017, Dagstuhl Seminar 17222: "Robust Performance in Database Query Processing"  Link


Level 7, Room 7.03
Doug McDonell Building (Bldg 168)
University of Melbourne
Parkville, VIC 3052
Phone: +61 3834 47220
  • *This is a post-peer-review, pre-copyedit version of an article published in VLDB Journal. The final authenticated version is available online at: