Re: TABLESAMPLE patch is really in pretty sad shape

> > If it's
> > to stay, it *must* get a line-by-line review from some committer-level
> > person; and I think there are other more important things for us to be
> > doing for 9.5.
> >
>
> Honestly, I am very surprised by this.

Tom's partial review found quite a crop of unvarnished bugs:

1. sample node can give different tuples across rescans within an executor run
2. missing dependency machinery to restrict dropping a sampling extension
3. missing "pg_dump --binary-upgrade" treatment
4. "potential core dumps due to dereferencing values that could be null"
5. factually incorrect comments
6. null argument checks in strict functions
7. failure to check for constisnull
8. "failure to sanity-check" ntuples
9. arithmetic errors in random_relative_prime()

(That's after sifting out design counterproposals, feature requests, and other
topics of regular disagreement.  I erred on the side of leaving things off
that list.)  Finding one or two like that during a complete post-commit review
would be business as usual.  Finding nine in a partial review diagnoses a
critical shortfall in pre-commit review vigilance.  Fixing the bugs found to
date will not cure that shortfall.  A qualified re-review could cure it.