Reflexive vs. Recursive Queries and Self-Joins

People (mostly database people) keep asking what I meant by reflexive query in my previous posts. Some thought I was confusing a self-join with a recursive query that would allow my DNS server to answer a DNS query for a domain for which it is not authoritative. What I mean is a query that returns a caller and a callee; and then another query that returns the callee's callees. In a self-join, I can match employers to their managers, since both are in the same table. While the NSA-phone tracking system might use some self-joins, what makes the network part work is getting queries from queries, and jumping from callers to callees. Of course I'd like all the results timestamped, too. Recursive queries are a part of this, and SQL 2005 can do it. If I had a few gigabytes worth of phone data, I'd love to let SQL 2005 loose and see what connections I could see. When I say reflexive, though, I mean that I'm going to use my queries to start other queries, and not just as sub-queries. The recursive part could lead to infinite loops. I wonder if the NSA hit any infinite loops when testing their system. Fortunately, you can specify limits on recursion in SQL 2005.

The scary part of this is what would happen if I had the resources to make it run really fast and tuned it to be as efficient as possible. I could select a target and find all of its connections in a few seconds or a few minutes. The difference between seconds and minutes would make a huge difference. In a system where it takes a couple of seconds to generate results, nobody would notice if I ran a few "unofficial" queries on my friends. If it took a few minutes and precious computer time, then people would notice. Utilitarian ethics.

This begs the question: how much computer time (and tax dollars) does our government use tracking down everyone who calls reporters? Then again, leaking classified information is unethical, but people do it anway. Contextual ethics. Of course, there's also the issue of selective enforcement, but that's a legal issue, not an ethical one.

Thus we're left with utilitarian ethics vs. contextual ethics. Who knew that efficient queries and more processing power could give one type of ethics an advantage over the other?