Re: BUG #17561: Server crashes on executing row() with very long argument list

On Fri, Jul 29, 2022 at 10:41 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> I wrote:
> > I think the parser should've prevented this. It's in charge of
> > rejecting overlength SELECT lists, for example. Also, the limit
> > probably needs to be just MaxTupleAttributeNumber.
>
> Concretely, about as attached.
>
> In the existing code, if you just supply 10000 or so columns you
> reach this error in heaptuple.c:
>
> if (numberOfAttributes > MaxTupleAttributeNumber)
> ereport(ERROR,
> (errcode(ERRCODE_TOO_MANY_COLUMNS),
> errmsg("number of columns (%d) exceeds limit (%d)",
> numberOfAttributes, MaxTupleAttributeNumber)));
>
> I borrowed the errcode from that, but the wording from parse_node.c:
>
> if (pstate->p_next_resno - 1 > MaxTupleAttributeNumber)
> ereport(ERROR,
> (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
> errmsg("target lists can have at most %d entries",
> MaxTupleAttributeNumber)));
>
> I'm a bit inclined to adjust parse_node.c to also use TOO_MANY_COLUMNS
> (54011) instead of the generic PROGRAM_LIMIT_EXCEEDED (54000).

The patch looks good to me. Just wondering if there are any other types
of expressions that need to check for MaxTupleAttributeNumber in
parse_expr.c.

Thanks
Richard