Why don't DBMS's support ASSERTION

Question

So I recently learned about ASSERTION in my databases course, and my prof noted that major databases don\'t support it, even though it is in the SQL-92 standard. I tried go

Answer 1

"If you can, please note any database packages that implement it as well"

SIRA_PRISE supports this feature in full. Disclosure : I am the author.

(As for the actual question "why aren't DBMS vendors offering this" : you'd really have to ask the vendors, but (a) it is an extremely difficult problem to solve even in a truly relational system, (b) that complexity is severely exacerbated by the fact that SQL is nowhere near truly relational and (c) it is highly probable that most programmers believe themselves to be competent enough to achieve the same effects as declarative ASSERTIONS using triggers, and this at a not so much higher development cost.)