For those that are curious, she did some very important work in the development of relational database technology--specifically, on query optimization ( <a href="http:&#x2F;&#x2F;www.cs.columbia.edu&#x2F;~coms4111&#x2F;docs&#x2F;selinger.pdf" rel="nofollow">http:&#x2F;&#x2F;www.cs.columbia.edu&#x2F;~coms4111&#x2F;docs&#x2F;selinger.pdf</a> ).