Tom Reyes Email & Phone Number

Austin, Texas Area

Contribute to improving performance of leading edge big data business intelligence systems

1) Take initiative to finally fix query optimizer update statistics problem that has been occurring at HP IT & other HP Neoview customers for over a year. Successfully solve the problem by understanding root cause of the problem (transient failures at intermediate steps that can be retried) and avoiding the mental trap of trying to reproduce & debug customer-reported update statistics failures (that are not reproducible).2) Fix query optimizer histogram reading & caching problem that has progressively worsened into a critical case. Solve the recurring query compiler crash by systematically finding, removing, refactoring semi-working patches that have accreted over time in the fetching & caching of single-column & multi-column histograms. Redesign multi-column histograms to reduce their memory footprint by over 100-fold. This fix has held up to the heavy use of an HP-size EDW.3) Implement risk-premium based robust query optimization techniques that drastically reduced incidence of bad query plans at HP IT & other Neoview customers without unduly sacrificing query performance. HP has applied a patent for this work: “Risk-premium based database query optimization” patent application 20100191720.4) Implement computation and use of maximum cardinality estimates to further improve robustness of plans generated by query optimizer. HP has applied a patent for this work: “System and method for optimizing queries using maximum cardinality estimates” USPTO application 20110060731.5) Implement query plan caching that reduces average compile time without sacrificing query run time & plan quality. HP has patented this work as: a) “Hybrid database query caching” patent 7743053, b) “Selectivity-based optimized query plan caching” patent application 20110029508, andc) “Memento query optimizer” patent application filed April 2011.

Austin, Texas Area

6) Implement embedding of statically compiled SQL modules into NonStop application executable files to simplify configuration & deployment of NonStop static SQL applications. HP patented this work as “Systems and methods for handling multiple static query modules for distinct environments” patent 7765531.7) Implement a Unicode lexer to support Tandem’s internationalization of its NonStop SQL/MX product.

Implemented UniSQL/M multidatabase system to integrate and federate UniSQL/X, Oracle, Microsoft SQL Server, Sybase, Informix, Versant databases, and flat files into a single integrated system as described in the book:Modern Database Systems: The Object Model, Interoperability, and Beyond. Won Kim (editor), ACM Press & Addison-Wesley 1995, ISBN 0-201-59098-0, pp 621-648 “Schema Architecture of the UniSQL/M Multidatabase System”.

1) Helped implement the Amoco Distributed Database System federation of IBM DS/SQL, DB2 MVS, RIM, and flat file data sources.Amoco patented this work as “Fault-tolerant distributed database system and method for the management of correctable subtransaction faults by the global transaction source node” patent 5247664.This work is also described in Modern Database Systems: The Object Model, Interoperability, and Beyond. Won Kim (editor), ACM Press & Addison-Wesley 1995, ISBN 0-201-59098-0, pp 683-701 “Overview of the ADDS System”.2) Implemented a portable screen manager. This work is described in Software Practice and Experience volume 20, issue 10 pages 1007-1014, October 1990 “Implementation of a portable screen manager”.3) Implemented a retargetable Fortran vector code generator for an array processor. This work is described in “A retargetable vector code generator”, 1987 Proceedings of the National Computer Conference, afips, pp. 657.

M.S., Computer Sciences

M. Eng., Industrial Engineering