Re: using index or check in ALTER TABLE SET NOT NULL

Stephen Frost <sfrost@snowman.net> writes:
> Isn't the first concern addressed by using SPI..?

I did not look at the patch yet, but TBH if it uses SPI for sub-operations
of ALTER TABLE I think that is sufficient reason to reject it out of hand.
Doing things that way would create way too much of a vulnerability surface
for code touching a partially-updated table.  At minimum, we'd have to
blow holes in existing protections like CheckTableNotInUse, and I think
we'd be forever finding other stuff that failed to work quite right in
that context.  I do not want ALTER TABLE going anywhere near the planner
or executor; I'm not even happy that it uses the parser (for index
definition reconstruction).
        regards, tom lane