Re: generic plans and "initial" pruning

On Thu, Dec 5, 2024 at 2:32 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Tomas Vondra <tomas(at)vondra(dot)me> writes:
> > I'm not forcing you to do elog, if you think ereport() is better. I'm
> > only asking because AFAIK the "policy" is that ereport is for cases that
> > think can happen (and thus get translated), while elog(ERROR) is for
> > cases that we believe shouldn't happen.
>
> The proposed coding looks fine from that perspective, because it uses
> errmsg_internal and errdetail_internal which don't give rise to
> translatable strings. Having said that, if we think this is a
> "can't happen" case then it's fair to wonder why go to such lengths
> to format it prettily. Also, I'd argue that the error message
> style guidelines still apply, but this errdetail doesn't conform.

Thinking about this further, perhaps an Assert is sufficient here. An
Append/MergeAppend node's part_prune_index not pointing to the correct
entry in the global "flat" list of PartitionPruneInfos would indicate
a bug. It seems unlikely that user actions could cause this issue.

--
Thanks, Amit Langote