- Belmpas Theofilos sdi1400119@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, B.Sc. student
- Chalatsis Dimitrios sdi1400219@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, B.Sc. student
- Gkini Orest sdi1400036@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, B.Sc. student
- Kamaras Georgios sdi1400058@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, B.Sc. student
- Michas Georgios sdi1400109@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, B.Sc. student
- Svingos Christoforos csvingos@di.uoa.gr, University of Athens, Department of Informatics and Telecommunications, Ph.D. student (coordinator)
- Professor Yannis Ioannidis yannis@di.uoa.gr, University of Athens
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The team members want to thank Evangelos Nikolopoulos (University of Athens, Madgik Lab) for his fruitful discussions during the development of the algorithms.
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The team members would like to thank professor Yannis Ioannidis (University of Athens, Madgik Lab, Athena RC) for motivating them.
This Join queries project was developed during the Spring of 2018 for the ACM SIGMOD Programming Contest 2018. For more information on the contest, please visit the contest's website.
Each time a batch of queries is received, each query is parsed, cleaned from weak filters and an optimal join tree is created to guide the query execution in the most efficient way. In the end of the batch, the queries are sorted based on a cost estimation and are scheduled for execution accordingly. This way they are executed in parallel in an efficient way and the checksums of their results are collected. For the joins, the Radix Join algorithm utilized. The checksums are then printed in the order that the queries came.
Several cache optimizations and optimizations based on statistics collected during each query's preprocessing phase have been applied during the above process. Also, a Job Scheduler has been used to assist in the optimal parallelization of critical parts of our program, like checksum calculation and filter application.
- Radix Join (MIT License)