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Konstantinos Krikellas
Electrical and Computer Engineer
PhD candidate in Database Systems
| Email : K <dot> Krikellas <at> sms <dot> ed <dot> ac <dot> uk |
I am a PhD candidate in the Database Group at the School of Informatics, University of Edinburgh.
I am supervised by Stratis Viglas and Marcelo Cintra.
I have graduated from the School of Electrical and Computer Engineering, National Technical University of Athens.
Research interests
My research interests cover databases, hardware architecture and distributed systems. More specifically, I am currently examining:
- Compiler optimization techniques for database applications
- Processor architecture: features and trends
- Query evaluation using template-based code generation
- Parallelism in Chip Multi-core Processors (CMPs)
- Query optimization based on hardware performance metrics
- Thread scheduling for intra-query parallelism on CMPs
- Consistency issues in database replication
Research projects
- My PhD research project concerns the development the Holistic Integrated QUery Engine (HIQUE), a query engine prototype
that adopts per-query code generation and implements all basic query operations (sort, hash partition, join, aggregate) in ways
that maximize cache locality and exploit hardware prefetching, so as to minimize processor stalls during query evaluation. HIQUE
incorporates an NSM-based storage system and can be used in both IO- and CPU-bound environments without any compromises in
concurrency control or recovery. It efficiently uses multithreading to adapt to multicore architectures and mitigate the
bottlenecks of memory accesses and thread synchronization.
- During my internship at Microsoft Research Cambridge I have developed a middleware-based replicated database prototype in C# on top
of the SQL Server 2008. The system incorporates the state-of-the-art in database replication and consists of the load balancer, the
transaction certifier and a number of database replicas, each hosting a standalone DBMS and a proxy. The system was used to examine
techniques for providing strong consistency, i.e. ensuring that the updates of each committed transaction are immediately visible to
all clients. Strong consistency so far required eager replication. We introduce lazy techniques that exploit workload information to
guarantee strong consistency without penalizing scalability.
Publications
- Konstantinos Krikellas, Marcelo Cintra, Stratis Viglas
Generating code for holistic query evaluation
(to appear in ICDE 2010)
- Konstantinos Krikellas, Sameh Elnikety, Zografoula Vagena, Orion Hodson
Strongly consistent replication for a bargain
(to appear in ICDE 2010)
Technical reports
- Konstantinos Krikellas, Marcelo Cintra, Stratis Viglas
Multithreaded query execution on multicore processors
(submitted for publication)
- Konstantinos Krikellas, Marcelo Cintra, Stratis Viglas
Scheduling threads for intra-query parallelism on multicore processors
(submitted for publication)
Internships
- Systems and Networking group,
Microsoft Research (MSR) Cambridge, United Kingdom
Period : May 2008 – Aug 2008, Apr 2009 – June 2009
Mentors: Zografoula Vagena, Sameh Elnikety and Orion Hodson
Teaching experience
- Tutor for Object Oriented Programming, 2nd semester, BSc Computer Science, University of Edinburgh (2008, 2009)
- Tutor for Computer Systems & Software Engineering, 3nd semester, BSc Computer Science, University of Edinburgh (2008)
- Tutor for Advanced Database Systems, MSc Computer Science, University of Edinburgh (2008, 2009)
Personal
I enjoy playing football and volleyball, cycling, swimming, hunting and travelling.
I am a member of the Edinburgh University's Volleyball team.
