Hotsos Symposium Speaker – Bryn LLewellyn

Mr. Llewellyn is a returning Hotsos Symposium presenter.


Bryn LlewellynBryn has worked in the software field for 30 years. He joined Oracle UK in 1990, at the European Development Center, to work in the Oracle Designer team. He transferred to the Oracle Text team and then into Consulting as the Text specialist for Europe. He relocated to Redwood Shores in 1996 to join the Oracle Text Technical Marketing Group. He has been the Product Manager for PL/SQL since 2001.

It's hard for Bryn to remember his life before Oracle. He started off doing image analysis and pattern recognition at Oxford University (programming in FORTRAN!) and then worked in Oslo, first at the Norwegian Computing Center and then and in a startup. In Norway, Bryn programmed in Simula (its inventors were his close colleagues). This language is recognized the first object-oriented programming language and was the inspiration for Smalltalk and C++.

Presentation Title

Bryn Llewellyn and Maria Colgan: Implement Extensible In-Database Analytics by Programming MapReduce in SQL and PL/SQL


The MapReduce programming model lets developers without experience with parallel and distributed systems utilize the resources of a large, multi-CPU system. Hadoop clusters can be used to implement this model; but Oracle Database also provides mechanisms to support the same model – and with less programming. SQL's analytic capabilities are more powerful than many experienced programmers suspect; but detecting complex patterns within suitably characterized, independent subsets of the complete data set sometimes needs user-written procedural code. Enter in-database MapReduce: pipelined PL/SQL table functions declaratively specify, with a few keywords, how parallel query should do the "map"; then the procedural body does the "reduce".

Bryn and Maria address ways to implement an application to solve a specific problem where, because of the typically huge volumes of data that must be distilled down to provide interesting information, performance matters. A person whose job it is to work with an installed system, won't be able to use what he explains in his talk to tune its performance.

Presentation Materials

Presentation materials are available online to attendees only.


The speaker schedules can be found at the following links: