Optimizer developer for AWS Redshift.

Query engine and optimizer architect for SAP Sybase IQ and HANA Dynamic Tiering. IQ is an ANSI SQL compliant clustered database product designed for the terabyte to petabyte scale data warehouse and data mart markets. IQ’s competitive advantages are its exceptional multi-user performance and its near linear distributed scaling, enabling it to support thousands of concurrent active users. IQ set two Guinness World Record Book performance records, and set price-performance records for the TPC-H decision support benchmark at the 100 gigabyte, 300 gigabyte, 1 terabyte, and 3 terabyte scales.Defined the architectural framework for the query optimizer that compiles the SQL for queries into data-flow trees capable of executing those queries. Refined the associated architecture for the data-flow run-time system. Guided the object-oriented design and C++ implementation efforts of up to twelve query processing engineers. Designed and implemented most of the optimizer, including fundamental representations for query blocks and query operators, and the subsystems for predicate and expression simplification, for predicate inference, and for join topology optimization. Designed and implemented many of the components in the run-time system, including much of the index-based predicate execution subsystem, and twelve different join algorithms. Applied optimization techniques to improve the performance of various algorithms, refined the selection of alternative algorithms, developed new algorithms, optimized code execution paths, replaced synchronous code with multi-threaded parallel and distributed code, and eliminated numerous performance bottlenecks. Analyzed numerous customer performance issues, and used those issues to identify additional optimization opportunities for future product versions.

Architect and Project Lead for the six member RuleWorks product team. RuleWorks was a novel portable modular object-oriented rule-based forward-chaining inference language for building expert systems, which was implemented in C.Project Lead for the six member team developing the DEC OPS5 forward-chaining inference language compiler product.Developed and taught seminars on artificial intelligence, rule-based technology, active values, and neural networks.

Worked on HDTV simulations and artificial intelligence projects.