On Fri, 12 Jun 2015 01:45:50 +0100 Simon Slavin <slavins at bigfraud.org> wrote:
> There are plenty of queries which can be expressed in a SQL database > but can't be answered without a computer which can reprogram itself Are there? Do you mean there are SQL queries like that? Or do you mean there are such queries that could be asked of a relational database but cannot be expressed in SQL? There are queries that cannot be formulated in first order predicate logic, and recursion is the single capability of SQL that exceeds FOPL power. Unless the recursion is circular, I don't see how an SQL query over a finite database could fail to terminate. --jkl