Re: BUG #18467: postgres_fdw (deparser) ignores LimitOption

Hi,

and 2) ORDER BY must already
> > have been determined to be safe to push down before we get here.
>

When I read the code, the decision for that seems to happen in the next
line where this patch proposes to modify:

/*
> * Also, the LIMIT/OFFSET cannot be pushed down, if their expressions are
> * not safe to remote.
> */
> if (!is_foreign_expr(root, input_rel, (Expr *) parse->limitOffset) ||
> !is_foreign_expr(root, input_rel, (Expr *) parse->limitCount))
> return;

Hence, I thought it is OK to add this new check to this place.

So
> > in that case, if getting here, we can consider that WITH TIES is also
> > safe to push down (if the remote is v13 or later).

See Tom's response here on why it might not be a good idea to pushdown
WITH TIES:
https://www.postgresql.org/message-id/2114796.1715878709%40sss.pgh.pa.us

I think, at least not with this patch, this patch is like a bug-fix. If
intended, it should be possible to
pushdown WITH TIES with a follow-up patch?

Thanks,
Onder