Re: BUG #17800: ON CONFLICT DO UPDATE fails to detect incompatible fields that leads to a server crash

Hi,

On 2023-02-24 17:12:43 -0500, Tom Lane wrote:
> OK, so this worked out quite well ... it's only about 50 net new lines
> of code, and there's no data structure changes outside the contents of
> compiled expressions, so no reason to fear ABI problems.

Nice.

> I did the renaming you had comments suggesting, but perhaps you want
> to bikeshed those names?

Not really. I guess it'd be mildly nicer to have Expr somewhere in the name,
but whatever.

> @@ -677,20 +680,8 @@ ExecBuildUpdateProjection(List *targetList,
> }
>
> /*
> - * If we're evaluating the tlist, must evaluate any resjunk columns too.
> - * (This matters for things like MULTIEXPR_SUBLINK SubPlans.)
> + * We don't bother evaluating any tlist entries that are marked resjunk.
> */
> - if (evalTargetList)
> - {
> - for_each_cell(lc, targetList, lc)
> - {
> - TargetEntry *tle = lfirst_node(TargetEntry, lc);
> -
> - Assert(tle->resjunk);
> - ExecInitExprRec(tle->expr, state,
> - &state->resvalue, &state->resnull);
> - }
> - }
>
> /*
> * Now generate code to copy over any old columns that were not assigned

The "don't bother" comment looks a bit lonely now :)

Greetings,

Andres Freund