C. Mohan

Chandrasekaran Mohan
Born	(1955-08-03) August 3, 1955 Tamil Nadu, India
Occupation	Computer scientist
Years active	1981–2020 (IBM), 2020–present (academic and advisory roles)
Known for	ARIES recovery algorithm, Presumed Abort commit protocol, database systems research

Chandrasekaran Mohan (born 3 August 1955 in Tamil Nadu, India) is a computer scientist of Indian origin who later became an American citizen. After completing his undergraduate education in Chennai, he relocated to the United States in 1977 to pursue graduate studies and obtained US citizenship in 2007. Mohan concluded a distinguished 38.5-year career at IBM Research by retiring in June 2020 as an IBM Fellow at the IBM Almaden Research Center located in San Jose, California. Presently, he holds the position of visiting professor at Tsinghua University, China, and acts as Honorary Advisor to the Tamil Nadu e-Governance Agency (TNeGA) as well as an advisor to the Kerala Blockchain Academy.

Education

Mohan received his doctorate in computer science from the University of Texas at Austin in 1981. Prior to that, he completed a B.Tech. degree in chemical engineering at IIT Madras in 1977. His earlier schooling took place in Vellore, Tamil Nadu.

Career

Following his PhD completion in database systems in 1981, Mohan joined the IBM Research facility in San Jose, where he contributed to several projects including R*, Starburst, Exotica, and DBCache. Between 1998 and 1999, he was a visiting scientist at INRIA Rocquencourt before returning to IBM. From June 2006 through January 2009, he served as Chief Scientist for IBM India based in Bangalore.

After his tenure in India, Mohan resumed work at the IBM Almaden Research Center, focusing on Storage Class Memory technologies, advancements in Big Data, enhancements for Hybrid Transactional/Analytical Processing (HTAP) within IBM Db2 and Apache Spark, along with blockchain and distributed ledger systems. He has been a frequent keynote speaker addressing topics such as NoSQL, NewSQL, modern relational database system improvements, and Big Data analytics.

Since 2017, Mohan has actively lectured on blockchain and distributed ledger technologies, co-organizing related seminars and presenting keynotes on permissioned blockchain platforms. In August 2016, he was appointed as a visiting professor at Tsinghua University's School of Software.

His extensive publications cover areas including databases, workflow management, transaction processing, and blockchain technology. Per Google Scholar, Mohan holds an h-index of 68 and an i10-index of 141. He is best known as the principal inventor behind the ARIES suite of recovery and concurrency control techniques as well as the widely adopted Presumed Abort commit protocol. His seminal papers on ARIES and Presumed Abort have become foundational references in transaction processing, recovery mechanisms, distributed commit protocols, and locking strategies. These works are featured in the "Red Book" series edited by ACM Turing Award recipient Prof. Michael Stonebraker, under the section "Techniques Everyone Should Know." Leading scholars have acknowledged ARIES as a critical component in database system architecture.

Mohan’s research contributions have shaped numerous products both within IBM and beyond, influencing technologies such as IBM Db2, MQSeries, IBM WebSphere, Informix, Cloudscape, IBM Notes, Microsoft SQL Server, and the IBM System z Parallel Sysplex environment.

An interview published by ACM SIGMOD in 2003 offers valuable perspectives on Mohan’s career at IBM along with his impact on database research and computing progress in India. Throughout his nearly four decades at IBM, he consistently prioritized technical innovation over managerial roles, emphasizing the importance of maintaining technical excellence—particularly relevant for emerging economies like India. His senior technical standing at IBM combined with a prolific patent record has been recognized by prominent business publications including Business Standard.

Awards

Throughout his career, Mohan's innovations, scholarly articles, inventions, and efforts in technology transfer have garnered considerable acclaim both within IBM and in the broader technology community.

In February 2009, he was inducted into the United States National Academy of Engineering (NAE) in recognition of his advancements in locking and recovery algorithms for database systems. That same year, he was honored as a Foreign Fellow by the Indian National Academy of Engineering (INAE). Mohan earned the prestigious 1996 Association for Computing Machinery (ACM) SIGMOD Edgar F. Codd Innovations Award for his groundbreaking contributions to database systems, marking him as the first recipient from outside the U.S. and only the fifth overall. This award has previously been bestowed upon luminaries such as Michael Stonebraker and Jim Gray, the latter of whom later received the ACM Turing Award.

In 2002, Mohan was distinguished as both an ACM Fellow and an IEEE Fellow. At the 1999 VLDB conference, he received the 10 Year Best Paper Award for his ARIES recovery algorithm, which has since become a standard feature in commercial database products and academic programs alike.

The Indian Institute of Technology Madras recognized Mohan as a Distinguished Alumnus in 2003, citing his pioneering contributions to database systems that form the backbone of modern information infrastructure and highlighting his far-reaching impact on research, industry, and society.

During his tenure at IBM, Mohan was the recipient of two Corporate Awards along with eight Outstanding Innovation/Technical Achievement Awards. He holds a portfolio of 50 granted or pending patents and was named an IBM Master Inventor in 1997.

Professional contributions

Mohan has provided an overview of his professional endeavors at IBM and beyond in a concise video presentation. He is a sought-after speaker who has delivered lectures in over 40 countries across North America, Western Europe, and India.

His advisory roles have included membership on the editorial boards of IEEE Spectrum, the VLDB Journal, and Distributed and Parallel Databases. Within IBM, Mohan participated in several key groups such as the Software Group Architecture Board's Steering Council, Technical Leadership Team (TLT), Academy of Technology, and Information Management Architecture Board. His previous appointments also encompass membership on IBM’s Research Management Council (RMC), India's Senior Leadership Team, Asset Architecture Board, as well as technical advisory panels for Bharti and Vodafone. Furthermore, he contributed to academic governance as part of the senate at the International Institute of Information Technology (IIIT) Bangalore.

External links

• Resume of C. Mohan