What have you needed out of ANSI SQL that is a gap in its Turing Completeness? Totally serious. A great many things can be dismissed as not being Turing Complete, so please provide us with some examples of why this is bad in ANSI SQL.
I did not mean that ANSI SQL was bad. However, by not being turning complete it has fundamental limitations that limit it from expressing certain logic (as you might need to do in a stored procedure). This frequently means that you must use proprietary extensions to SQL (such as PL/SQL) to accomplish these tasks.
My interpretation of the parent post was that it was a response to a comment about vendor lock in. I was only trying to point out that it is not always possible to ensure compatibility between databases by writing strict ANSI SQL.