I&#x27;m not really sure the point of your post.  Why should I roll my own relational query engine in Scheme when I can use one with hundreds of man-years of development, and thousands of man-years of testing behind it, like PostgreSQL?<p>Also, I sincerely hope you&#x27;re not trying to synthesize ASICs out of code from a language with constructs like call&#x2F;cc.