Re: display offset along with block number in vacuum errors

Thanks Michael for looking into this.

On Sat, 25 Jul 2020 at 15:02, Michael Paquier <michael@paquier.xyz> wrote:
>
> On Fri, Jul 24, 2020 at 11:18:43PM +0530, Mahendra Singh Thalor wrote:
> > In commit b61d161(Introduce vacuum errcontext to display additional
> > information), we added vacuum errcontext to display additional
> > information(block number) so that in case of vacuum error, we can identify
> > which block we are getting error.  Addition to block number, if we can
> > display offset, then it will be more helpful for users. So to display
> > offset, here proposing two different methods(Thanks Robert for suggesting
> > these 2 methods):
>
>     new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
>     vacrelstats->blkno = new_rel_pages;
> +   vacrelstats->offnum = InvalidOffsetNumber;
>
> Adding more context would be interesting for some cases, but not all
> contrary to what your patch does in some code paths like
> lazy_truncate_heap() as you would show up an offset of 0 for an
> invalid value.  This could confuse some users.  Note that we are
> careful enough to not print a context message if the block number is
> invalid.

Okay. I agree with you. In case of inavlid offset, we can skip offset
printing. I will do this change in the next patch.

Thanks and Regards
Mahendra Singh Thalor
EnterpriseDB: http://www.enterprisedb.com