Supposedly you came to this page to find out my qualifications for something I wrote so here is a brief synopsis of my qualifications in computer topics:
I have a PhD in Computer Science. In grad school my primary research interest was in programming languages design, semantics, and implementation. I wrote an optimizing compiler for a concurrent constraint programming language as part of my dissertation.
I spent five years as a sort of combo sales engineer/developer/professional services engineer doing user-level applications with graphical user interfaces and typically a SQL back end. I would work with customers to write requirements then write the software (and QA it myself) then deliver and implement at the customer site.
The majority of my career has been on SQL database internals on several different DBMS's. One of these DBMS's was for high performance on data with a small working set. Another one was for "big data" (on the order of terabytes) in a distributed database. Having worked only in small companies, I've done the whole gamut from SQL compiler to planner to execution engine to storage components.