Обсуждение: confusing message in check_tuple

hi.

in contrib/amcheck/verify_heapam.c, check_tuple
        report_corruption(ctx,
                          psprintf("number of attributes %u exceeds
maximum expected for table %u",
                                   ctx->natts,
                                   RelationGetDescr(ctx->rel)->natts));
i think it should be
        report_corruption(ctx,
                          psprintf("number of attributes %u exceeds
maximum expected for table %u",
                                   ctx->natts,
                                   RelationGetRelid(ctx->rel)));

or we can rephrase it another way, also mentioning
``RelationGetDescr(ctx->rel)->natts``.

On 12.06.25 08:26, jian he wrote:
> in contrib/amcheck/verify_heapam.c, check_tuple
>          report_corruption(ctx,
>                            psprintf("number of attributes %u exceeds
> maximum expected for table %u",
>                                     ctx->natts,
>                                     RelationGetDescr(ctx->rel)->natts));

Agreed this is misleading.

> i think it should be
>          report_corruption(ctx,
>                            psprintf("number of attributes %u exceeds
> maximum expected for table %u",
>                                     ctx->natts,
>                                     RelationGetRelid(ctx->rel)));
> 
> or we can rephrase it another way, also mentioning
> ``RelationGetDescr(ctx->rel)->natts``.

I think they did want to mention RelationGetDescr(ctx->rel)->natts.  How 
about

"number of attributes %u exceeds maximum expected for table (%u)"

On Tue, Jun 17, 2025 at 1:21 PM Peter Eisentraut <peter@eisentraut.org> wrote:
>
> On 12.06.25 08:26, jian he wrote:
> > in contrib/amcheck/verify_heapam.c, check_tuple
> >          report_corruption(ctx,
> >                            psprintf("number of attributes %u exceeds
> > maximum expected for table %u",
> >                                     ctx->natts,
> >                                     RelationGetDescr(ctx->rel)->natts));
>
> Agreed this is misleading.
>
> > i think it should be
> >          report_corruption(ctx,
> >                            psprintf("number of attributes %u exceeds
> > maximum expected for table %u",
> >                                     ctx->natts,
> >                                     RelationGetRelid(ctx->rel)));
> >
> > or we can rephrase it another way, also mentioning
> > ``RelationGetDescr(ctx->rel)->natts``.
>
> I think they did want to mention RelationGetDescr(ctx->rel)->natts.  How
> about
>
> "number of attributes %u exceeds maximum expected for table (%u)"
>

ctx->natts is "int", so it should be
psprintf( "number of attributes %d exceeds maximum expected for table (%u)",
         ctx->natts, RelationGetRelid(ctx->rel));
?

we also need change src/bin/pg_amcheck/t/004_verify_heapam.pl
in there, we have

        push @expected,
          qr/${$header}number of attributes 67 exceeds maximum
expected for table 3/;

        push @expected,
          qr/${$header}number of attributes 2047 exceeds maximum
expected for table 3/;

Hi,

On Tue, Jun 17, 2025 at 07:21:13AM +0200, Peter Eisentraut wrote:
> On 12.06.25 08:26, jian he wrote:
> > in contrib/amcheck/verify_heapam.c, check_tuple
> >          report_corruption(ctx,
> >                            psprintf("number of attributes %u exceeds
> > maximum expected for table %u",
> >                                     ctx->natts,
> >                                     RelationGetDescr(ctx->rel)->natts));
> 
> Agreed this is misleading.
> 
> > i think it should be
> >          report_corruption(ctx,
> >                            psprintf("number of attributes %u exceeds
> > maximum expected for table %u",
> >                                     ctx->natts,
> >                                     RelationGetRelid(ctx->rel)));
> > 
> > or we can rephrase it another way, also mentioning
> > ``RelationGetDescr(ctx->rel)->natts``.
> 
> I think they did want to mention RelationGetDescr(ctx->rel)->natts.

+1, I think that we usually want to be able to compare actual vs expected.

> How
> about
> 
> "number of attributes %u exceeds maximum expected for table (%u)"

I thought about adding the table name in the message but it looks like it's already
there:

"
Expected corruption message output stdout /(?^:(?^ms:heap table "postgres\.public\.test", block 0, offset 9:\s+)number
ofattributes 2047 exceeds maximum expected for table 3)
 
"

So that your proposal makes sense to me.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com