Dr. Kitsuregawa graduated from the Department of Electronics Engineering at the University of Tokyo in 1978, completed his doctorate in the Department of Information Engineering at the same university, and received his Ph.D. in 1983. He became a lecturer at the Institute of Industrial Science in 1983, an associate professor in 1984, and a professor in 1997, all at the same university. From 2010, he was director-general of the Earth Observation Data Integration & Fusion Research Initiative at the same university. In 2013, he became a director-general of the National Institute of Informatics (NII), only one national institute for informatics. Since April 2021, he has been an university professor at the University of Tokyo.

Anticipating the arrival of today’s Big Data era, from the 1980s Dr. Kitsuregawa undertook research on boosting the performance of database systems for huge data, and made numerous trailblazing distinguished achievements, and explored a wide variety of application fields.

He demonstrated strong leadership in data engineering in Japan, including his service as a representative for research on “information explosion,” which was the biggest specific area in the information field. This research was started eight years before the Big Data Initiative was launched in the U.S.

In the early 1980s when relational databases operated extremely slowly, he studied hash join, a method for high-speed execution of relational operations. He proposed dynamic staging, bucket tuning and other methods, and achieved high performance in various parallel machines, such as those using shared memory, distributed memory, or distributed shared memory.

Virtually all relational databases being used today have adopted this method. This method is referred to as “Grace hash join” in Wikipedia. It is now a basic method of operating a relational database. In recognition of his achievements in enhancing database performance, including those mentioned above, he received the ACM SIGMOD E. F. Codd Innovations Award, which is the most prestigious award in database systems research. He was the first recipient of this Award to come from Asia. In the early 2000s, he invented an original database execution method for the Big Data era, a method he called “out of order execution.” This method dramatically enhances performance just by making the operation for storage input/output recursive and asynchronous even when the resources, such as CPUs and disks, remain unchanged. Processing speed with this method was boosted by a factor of about 1,000 compared to conventional methods. In collaboration with Hitachi, he developed a commercial system, which became the first to enter the 100-TByte realm, the highest in the TPC-H, a world-standard benchmark. This method boosts the performance not only of disks but also of flash memory devices, and is very effective even for non-relational databases, such as Hadoop. Research on this novel method continues even today.

In recent years, he has been applying out-of-order data processing to solving social issues, such as those in the medical field. He has constructed an epoch-making system that can handle clinical data consisting of about 200 billion records in a matter of minutes. This system is now employed by many users, such as those in the Japanese Society of Hypertension and the Japan Diabetes Society.

Since the 1980s, he has been constructing a gigantic data platform, called DIAS, for handling data related to the global environment. The platform has grown to handle 50 PBytes of data and is accessed by about 8,000 users. A variety of applications have been developed to utilize this platform, such as those relating to real-time prediction of floods and a system for controlling the release of dam water in advance of expected heavy rainfall. The platform is also used to implement countermeasures against floods and drought in Myanmar, Sri Lanka, Brasil and many other countries.

For the achievements mentioned above, he was designated as a fellow by the IEICE, the Information Processing Society of Japan, the IEEE, and ACM, and as an honorary member by the China Computer Federation. He also received many awards, including the Medal with Purple Ribbon, Legion d’Honneur, Chevalier, Japan Academy Medal, IEEE Innovation in Societal Infrastructure Award, C&C Award, and National Invention Award “21st Century Invention Award.”

As mentioned above, Dr. Kitsuregawa’s achievements in the development of the electronic, information and communication fields and his application of the technologies he has developed to solving social issues are truly outstanding. Therefore, we confidently recommend that he be designated a fellow, honorary member of the IEICE.